JP3694449B2 - Solution concentration measuring method and solution concentration measuring apparatus - Google Patents

Solution concentration measuring method and solution concentration measuring apparatus Download PDF

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JP3694449B2
JP3694449B2 JP2000278797A JP2000278797A JP3694449B2 JP 3694449 B2 JP3694449 B2 JP 3694449B2 JP 2000278797 A JP2000278797 A JP 2000278797A JP 2000278797 A JP2000278797 A JP 2000278797A JP 3694449 B2 JP3694449 B2 JP 3694449B2
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test solution
concentration
reagent
solution
mixing
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JP2001194308A (en
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達朗 河村
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Panasonic Corp
Panasonic Holdings Corp
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Panasonic Corp
Matsushita Electric Industrial Co Ltd
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【0001】
【発明の属する技術分野】
本発明は、被検溶液中に溶解している溶質の濃度、例えばタンパク質濃度および旋光性物質の濃度を計測する方法および装置に関するものである。
【0002】
【従来の技術】
従来の溶液濃度計測装置としては、分光器、液クロマトグラフィなどがある。また、尿検査装置としては、試薬を含浸した試験紙などに尿を浸し、これの呈色反応を分光器などによって観測し、尿の成分を検査するものがあった。
ここで使用される試験紙は、グルコース、タンパク質等の個々の検査項目に応じてそれぞれ用意されている。
【0003】
しかしながら、上記のような方式においては、装置が大規模になるという問題があった。また、計測できる濃度範囲が限定されており、限定濃度範囲を超えた被検溶液は希釈して供試する必要があり、工程が煩雑になる問題もあった。さらに、被検溶液そのものの濁りや光学窓の汚れに影響されて、正確な計測結果が得られない場合があった。また、被検溶液中に浮遊している各種粒子や泡等が、計測に使用されている光の光路中に存在すると、これによって誤動作が引き起こされるという問題があった。
【0004】
【発明が解決しようとする課題】
本発明は、上記の問題を解決して、信頼性が高く、小型で維持管理が容易な溶液濃度計測装置およびその装置設計を可能にする計測方法を提供することを目的とする。また、本発明は、簡便で高精度な尿検査を可能にする手段を提供することを目的とする。
【0005】
【課題を解決するための手段】
上記問題点を解決すべく、本発明は、被検溶液中の特定成分の濃度を計測する方法であって、前記特定成分に起因する被検溶液の光学特性を変化させる試薬を混入する前後の前記被検溶液の透過光強度および散乱光強度を計測し、前記試薬混入後の散乱光強度の計測値から、低濃度域の前記被検溶液中の前記特定成分の濃度を決定し、前記試薬混入後の透過光強度の計測値から、高濃度域の前記被検溶液中の前記特定成分の濃度を決定することを特徴とする溶液濃度計測方法を提供する。
【0006】
た、前記試薬混入前後の透過光強度の計測値と前記試薬混入前後の散乱光強度の計測値とを照合することにより、前記被検溶液中の浮遊粒子による誤計測の有無を検知するのが有効である。
【0007】
た、濃度が既知の基準溶液と前記被検溶液とについて、前記試薬混入前後の透過光強度および散乱光強度の少なくとも一方を同条件で計測し、前記基準溶液の計測値により、前記被検溶液の計測値を補正して前記被検溶液中の前記特定成分の濃度を求めるのが有効である。
前記基準溶液は、前記特定成分を含まない水であるのが有効である。
【0008】
さらに本発明は、上記溶液濃度計測方法によって前記被検溶液のタンパク質濃度を求め、前記試薬混入以前に前記被検溶液の旋光度を計測することによって前記被検溶液中の旋光性物質濃度を求め、ついで前記タンパク質濃度および前記旋光性物質濃度から、前記タンパク質以外の旋光性物質の濃度を求めることを特徴とする溶液濃度計測方法も提供する。
【0010】
また、本発明は、被検溶液に光を照射する光源と、前記光が前記被検溶液を透過するように前記被検溶液を保持するサンプルセルと、前記被検溶液を透過した光を検知する光センサー1と、前記被検溶液中を前記光が伝搬する際に発生した散乱光を検知する光センサー2と、前記被検溶液に前記被検溶液中の特定成分のみの光学特性を変化させる試薬を混入する混入機と、前記混入機を制御し、前記光センサーの出力信号を解析するコンピューターとを備え、前記試薬混入前後の前記光センサー1の出力信号の計測値から、高濃度域の前記被検溶液中の特定成分の濃度を求め、前記試薬混入前後の前記光センサー2の出力信号の計測値から、低濃度域の前記被検溶液中の特定成分の濃度を求めることを特徴とする溶液濃度計測装置も提供する。
【0011】
記試薬混入前後の前記光センサー1の出力信号の計測値と前記試薬混入前後の前記光センサー2の出力信号の計測値とを照合することにより、前記被検溶液中の浮遊粒子による誤計測の有無を検知するのが有効である。
【0013】
さらに、略平行光を投射する単色光源と、前記略平行光のうち特定方向の偏光成分のみを透過する偏光子と、前記被検溶液に磁場を印加する手段と、前記磁場を制御する磁場制御手段と、前記磁場を制御する際に前記磁場を振動変調する磁場変調手段と、前記被検溶液を透過した光のうち特定方向の偏光成分のみを透過する検光子と、前記検光子を透過した光を検知する光センサー3と、前記光センサー3の出力信号を前記磁場変調手段の振動変調信号を参照信号として位相敏感検波するロックインアンプと、前記磁場制御手段の磁場制御信号と前記ロックインアンプの出力信号にもとづいて前記被検溶液の旋光度を算出 し、これを旋光性物質の濃度に換算する手段とを備え、前記サンプルセルは前記偏光子を透過した光が透過するように前記被検溶液を保持しており、前記試薬混入前後に計測した被検溶液の透過光強度の計測値から、または前記光センサー3の出力信号を前記透過光の信号と見なして、前記光センサー3の出力信号の計測値から、前記被検溶液のタンパク質濃度を求め、前記算出された旋光度と前記タンパク質濃度から、前記被検溶液の前記タンパク質濃度と前記タンパク質以外の旋光性物質の濃度を確定することも有効である。
【0014】
【発明の実施の形態】
上述のように、本発明の溶液濃度計測方法は、被検溶液中の特定成分の濃度を計測する方法であって、前記特定成分に起因する被検溶液の光学特性を変化させる試薬を混入する前後の前記被検溶液の透過光強度および/または散乱光強度を計測し、これらの計測値にもとづいて、前記被検溶液中の特定成分の濃度を求めることを特徴とするものである。
【0015】
上記の試薬は、被検溶液中の濃度測定対象とする特定成分のみと反応して、変色や濁りなどを生じ、前記被検溶液にその特定成分の濃度に対応した度合いの光学的変化を引き起こすものである。このような試薬を被検溶液に混入させることで、被検溶液の光学特性を変化させ、この特定成分の濃度を測定することができる。例えば、尿を被検溶液とした場合には、試薬を混入してタンパク質成分を凝集させることで尿の光学特性を変化させ、試薬混入前後の散乱光強度の差(試薬混入後の散乱光強度−試薬混入前の散乱光強度)および/または試薬混入前後の透過光強度の比(試薬混入後の透過光強度/試薬混入前の透過光強度)から、尿中のタンパク質を求めることができる。
【0016】
さらに、本発明の溶液濃度計測装置は、前記被検溶液に光を照射する光源と、前記光が前記被検溶液を透過するように前記被検溶液を保持するサンプルセルと、前記被検溶液を透過した光を検知する光センサー1および/または前記被検溶液中を前記光が伝搬する際に発生した散乱光を検知するように配置した光センサー2と、前記被検溶液に前記被検溶液中の特定成分に起因する被検溶液の光学特性を変化させる試薬を混入する混入機と、前記混入機を制御し、前記光センサー1および/または光センサー2の出力信号を解析するコンピューターとを備え、前記試薬混入前後の前記光センサー1および/または光センサー2の出力信号の計測値から、前記被検溶液中の特定成分の濃度を求めることを特徴とするものである。
【0017】
上記の本発明による溶液濃度計測方法あるいは装置により、前記試薬混入前後の透過光強度または散乱光強度の少なくとも何れか一方を計測することによって、前記被検溶液中の特定成分の濃度を求めることができる。そして、透過光強度と散乱光強度の双方を計測することにより、さらに下記の利点が付加される。
まず、前記試薬混入前後の散乱光強度の計測値から、低濃度域の前記被検溶液中の前記特定成分の濃度を決定し、前記試薬混入前後の透過光強度の計測値から、高濃度域の前記被検溶液中の前記特定成分の濃度を決定することにより、より広い濃度範囲の被検溶液について、高精度に前記特定成分の濃度を求めることができる。なお、本発明においていう「高濃度」および「低濃度」については、後述する。
【0018】
さらに、前記試薬混入前後の透過光強度の計測値と前記試薬混入前後の散乱光強度の計測値とを照合することにより、前記被検溶液中における泡、未溶解の各種塩、ほこり、ゴミなどの浮遊粒子による誤計測の有無を検知することができ、誤測定や装置の誤作動を防止することができる。
また、濃度が既知の基準溶液と前記被検溶液とについて、前記試薬混入前後の透過光強度および/または前記試薬混入前後の散乱光強度を同条件で計測し、前記基準溶液の計測値により、前記被検溶液の計測値を補正して前記被検溶液中の前記特定成分の濃度を求めることにより、光学窓層などの透過率低下などの影響が消去され、さらに高精度な計測が可能になる。この場合、前記特定成分を含まない水を簡便な基準溶液として用いることができる。
【0019】
さらに、本発明においては、前記試薬混入以前に前記被検溶液の旋光度を計測するとともに、上記本発明によるいずれかの溶液濃度計測方法によって、前記被検溶液のタンパク質濃度を求め、前記タンパク質濃度と前記旋光度とから、前記タンパク質濃度と前記タンパク質以外の旋光性物質の濃度を確定することができる。この方法により被検溶液中のタンパク質とタンパク質以外の旋光性物質との度を同時に測定するために、下記の装置を用いることができる。
【0020】
即ち、略平行光を投射する単色光源と、前記略平行光のうち特定方向の偏光成分のみを透過する偏光子と、前記偏光子を透過した光が透過するように被検溶液を保持するサンプルセルと、前記被検溶液に磁場を印加する手段と、前記磁場を制御する磁場制御手段と、前記磁場を制御する際に前記磁場を振動変調する磁場変調手段と、前記被検溶液を透過した光のうち特定方向の偏光成分のみを透過する検光子と、前記検光子を透過した光を検知する光センサーと、前記光センサーの出力信号を前記磁場変調手段の振動変調信号を参照信号として位相敏感検波するロックインアンプと、前記磁場制御手段の磁場制御信号と前記ロックインアンプの出力信号にもとづいて前記被検溶液の旋光度を算出し、これを旋光性物質の濃度に換算する手段と、前記被検溶液に前記被検溶液中の特定成分のみの光学特性を変化させる試薬を混入する混入機と、前記混入機を制御し、前記光センサーの出力信号を解析するコンピューターとを備えた装置である。
【0021】
この装置により計測された前記試薬混入前後の前記透過光強度の計測値から、前記被検溶液のタンパク質濃度を求め、前記算出された旋光度と前記タンパク質濃度から、前記タンパク質濃度と前記タンパク質以外の前記被検溶液の旋光性物質の濃度を確定する。この場合、前記光センサーの出力信号を前記透過光の信号見なして、前記光センサーの出力信号の計測から、前記被検溶液のタンパク質濃度を計測することができる。
【0022】
さらに、上記の装置に加えて、前記略平行光を変調する手段を備えることにより、前記被検溶液に試薬を混入し、前記光センサーの出力信号を計測する際に、前記ロックインアンプの参照信号を前記略平行光の変調信号として前記光センサーの出力信号を位相敏感検波し、前記ロックインアンプの出力信号を前記透過光の信号と見なして、前記試薬混入前後の前記ロックインアンプの出力信号の計測値から、前記被検溶液のタンパク質濃度を求め、前記旋光度と前記タンパク質濃度から、前記タンパク質濃度と前記タンパク質以外の前記被検溶液の旋光性物質の濃度を確定することもできる。
【0023】
上記の本発明による溶液濃度計測方法あるいは溶液濃度計測装置により、尿を始めとする髄液、血清、血漿、唾液などの体液や、乳製品、酒、食酢などの食品、培養液などの産業用液、および人工透析液やその廃液などの被検溶液中に含まれる特定成分の濃度を求めることができる。これらの被検溶液中の濃度測定対象とする特定物質としては、ホルモン、酵素などの各種タンパク質、コレステロールなどの脂質、ウイルス、および細菌などが挙げられる。また、これらの特定物質の濃度を求める際に用いる試薬としては、トリクロロ酢酸、スルホサリチル酸などの酸性溶液や抗体溶液などを用いることができる。
【0024】
また、上記の本発明による溶液濃度計測方法あるいは溶液濃度計測装置により、上記被検溶液の測定可能な濃度範囲が拡大でき、被検溶液中のタンパク質などの上記特定成分の正確な濃度を簡便に計測できる。さらに、前記被検溶液の旋光度を計測した後、前記試薬を混入してタンパク質濃度を計測することで、タンパク質の濃度とグルコースなどのタンパク質以外の旋光性物質を同時に決定することができる。これらのことから、本発明による溶液濃度計測方法あるいは溶液濃度計測装置は、尿を被検溶液として尿タンパク濃度や尿糖値を測定して検査する場合に特に有用であり、検査の信頼性や精度を向上させ、検査工程を大幅に簡略化することができる。
以下、本発明の実施の形態を具体的な例を挙げて詳細に説明する。
【0025】
《実施の形態1》
被検溶液に、被検溶液に含まれる特定成分に起因して前記被検溶液の光学特性を変化させる試薬を混入する前後の透過光強度および/または散乱光強度を計測し、それらの計測値から被検溶液中の特定成分の濃度を求める例について、以下に詳細に説明する。
【0026】
図1は溶液濃度測定装置の構成を模式的に示す正面図で、図2は図1の光学系のみを模式的に示す平面図である。図1および2において、1は半導体レーザモジュールからなる光源を示し、波長780nm、強度3.0mW、ビーム直径2.0mmの略平行光2を投射する。サンプルセル3は、ガラス製で上部に開放された開口部を有し、底面が10×10mm、高さが50mmの直方体状容器であり、側面は透明な光学窓である。このサンプルセル3は、その内部に収容された被検溶液10に略平行光2を照射することができ、また、透過光および散乱光9を外部に取り出すことができる。被検溶液10を透過した光を検知する光センサー4および被検溶液中を光が伝搬する際に発生した散乱光9を検知する光センサー5により、それぞれ透過光および散乱光が検知される。試薬を注入する注入口6はサンプルセル3の底部に位置している。ピペッタ7により、サンプルセル3中の被検溶液に注入口6を通じて、試薬を所定容量注入する。コンピューター8は、光源1およびピペッタ7を制御し、光センサー4および5の出力信号を解析する。
【0027】
上記の溶液濃度測定装置を用いて、尿を被検溶液として尿タンパク濃度を検査する場合の動作は次の通りである。
まず、被検溶液10をサンプルセル3へ導入する。コンピューター8が光源1を動作させ、同時に光センサー4および5の出力信号のモニターを開始する。次に、コンピューター8がピペッタ7を制御して、注入口6を通じてスルホサリチル酸試薬(硫酸ナトリウムを2−ヒドロキシ−5−スルホ安息香酸水溶液に溶解させた試薬)をサンプルセル3へ導入する。被検溶液にスルホサリチル酸試薬が混入されると、タンパク質成分が凝集して被検溶液10が濁り、透過光強度が低下し、散乱光強度が増加する。この試薬の混入の前後の光センサー4および5のそれぞれの出力信号の計測値を解析することで、タンパク質濃度を求める。
【0028】
タンパク質濃度が2mg/dlの被検溶液10を用い、上記の方法で測定した透過光強度および散乱光強度、即ち、光センサー4および5の出力信号をそれぞれ図3および4に示す。同様に、タンパク質濃度が15mg/dlの被検溶液を用いた時の各出力信号を図5および6に示し、タンパク質濃度が100mg/dlの被検溶液を用いた時の各出力信号を図7および8に示す。図3〜8において、横軸は試薬混入後の経過時間(秒)を示し、混入前60秒から混入後300秒までの透過光あるいは散乱光の強度変化を示している。図3、5および7から、透過光の強度(光センサー4の出力信号)は、タンパク質が高濃度になるほど低下していることがわかる。また、図4、6および8から散乱光の強度(光センサー5の出力信号)は、タンパク質が高濃度になるほど増加していることがわかる。
【0029】
このような、散乱光強度の変化および透過光強度の変化とタンパク質濃度との関関係をそれぞれ図9および10に示す。図9においては、試薬混入後300秒経過時の散乱光強度と混入前の散乱光強度との差(試薬混入後の散乱光強度−試薬混入前の散乱光強度)を縦軸に示した。図10においては、試薬混入前の透過光強度と混入後300秒経過時の透過光強度との比(試薬混入後の透過光強度/試薬混入前の透過光強度)を縦軸に示した。なお、図9および10には前記の被検溶液以外に、タンパク質濃度が0、5、30、60mg/dlの尿を被検溶液としてそれぞれ追加して計測した結果を示した。これらの場合、計測した被検溶液はすべて、試薬の混入前には光学的に水と同程度に透明であり、透過光強度と散乱光強度は水と同じであった。従って、これらから得られた図9および図10の前記相関関係は、それぞれ尿中のタンパク質濃度を計測する際の標準的な検量線として使用できる。
【0030】
図9において、各実測値をスムーズに結んで実線で示し、散乱光強度の変化量(試薬混入前後の散乱光強度の差)に対して直線的に変化しているタンパク質濃度0〜15mg/dlの領域の実測値を結んだ直線を延長させて点線で示した。この実線と点線から明らかなように、タンパク質濃度が約15mg/dlまでは実線と点線が重なり、散乱光強度の変化量はタンパク質濃度に比例している。
しかし、これより高濃度になるにつれて、次第に比例関係よりも低い実測値を示している。これは、タンパク質濃度が高くなり、光が散乱される確率が高くなると、散乱光が発生した地点からサンプルセルの外まで伝搬する際に、再び散乱される確率も高くなり、光センサー5に散乱光が到達する確率が低下するからである。従って、散乱光強度の変化から濃度を算出する場合には、直線性が確保できる低濃度域(約15mg/dl以下)において、より高精度な濃度を求めることができる。
【0031】
図10において、横軸はタンパク質濃度を、縦軸(対数表示)は試薬混入前後の透過光強度の比を示す。各実測値をスムーズに結んで実線で示し、直線的に変化しているタンパク質濃度15〜100mg/dlでの実測値を結んだ直線を延長させて点線で示した。図10で示したように、タンパク質濃度が2mg/dlや5mg/dlのような低濃度の場合には、この点線から外れる場合がある。これは、図3と図5および7を比較すると明らかなように、全出力信号に比べて変化割合が小さすぎるため、各種ノイズの影響を受けやすいからである。このことから、透過光強度の計測値からタンパク質濃度を算出する場合において、各種ノイズの影響を避けるためには、被検溶液が高濃度域(約15mg/dl以上)にあることがより望ましいことが分かる。
【0032】
以上のようにして、試薬混入前後の透過光強度あるいは試薬混入前後の散乱光強度を計測することにより、被検溶液の特定成分の濃度を求めることができる。
さらに、上記双方の強度を計測することにより、低濃度域の被検溶液については、散乱光強度の計測値から溶液濃度を算出し、高濃度域の被検溶液については、透過光強度の計測値から溶液濃度を算出することで、実質的に高精度に測定できる被検溶液の濃度範囲、即ちダイナミックレンジを拡大できる。
これにより、従来必要であった高濃度被検溶液の希釈等の工程が不要になり、計測および検査の高精度化、効率化、省力化に有効な実用的効果を高めることができる。
尚、本実施の形態では、試薬混入直前と300秒経過時点の透過光強度および散乱光強度の計測値から溶液濃度を求めたが、この時間差は計測装置、被検溶液や試薬などの特性に応じて適宜に設定すればよい。
【0033】
本実施の形態においては、低濃度域を約15mg/dl以下、高濃度域を約15mg/dl以上とし、低濃度域では散乱光強度を計測し、高濃度域では透過光強度を計測すると高精度な結果が得られる。
しかし、本実施の形態における低濃度および高濃度の範囲は、サンプルセル3の光路長、散乱光9の被検溶液中における伝搬距離、および光学系の配置などの種々のファクタによって異なるため、上記数値範囲に限定されるものではない。
したがって、本発明においていう「低濃度」とは、被検溶液の特定成分濃度と散乱光強度の変化との関係を示すグラフにおいて(図9)、直線性を有する部分に対応する濃度範囲をいい、「高濃度」とは、被検溶液の特定成分濃度と透過光強度の比との関係を示すグラフにおいて(図10)、直線性を有する部分に対応する濃度範囲をいう。これらは、当業者であれば、本発明に係る方法を実施する前にあらかじめ決定しておくことができる。
【0034】
実際に透過光の光路長を上述した10mmよりも長くすれば、15mg/dl以下の濃度においても、透過光強度を高精度で計測することができる。
ただし、このように光路長を長くすると、高濃度域においては光センサー4の出力信号が小さくなりすぎ(約10-4V)、濃度を求めることが困難になる。さらに、光路長を長くすると、装置全体の規模も必然的に拡大することになり、実用上あまり好ましくはない。
以上のように、本発明によれば、装置の構成および規模が一定の制約を受ける場合において、散乱光および透過光の双方を利用することにより、高濃度域および低濃度域のすべてにおいて精度良く濃度を計測することができ、ダイナミックレンジを拡大することができる。
【0035】
《実施の形態2》
次に、図1および2の計測装置を用いて、各種塩などが析出して混濁した尿を被検溶液として特定成分の濃度を求める例について詳細に説明する。
まず、被検溶液10としてタンパク質濃度15mg/dlの混濁した尿をサンプルセル3へ導入し、実施の形態1の場合と同様にして、試薬混入前後の光センサー4および/または光センサー5の出力信号の変化を観測する。
この試薬混入前後の光センサー5および4の出力信号の経時変化をそれぞれ図11および12に示す。これらの図は、図3〜8と同様に試薬混入前60秒から混入後300秒までの出力信号の変化を示している。
【0036】
図11から明らかなように、試薬の混入前、即ち−60〜0秒における光センサー5の出力信号(散乱光強度)は0.05V程度である。実施の形態1に用いたような混濁が無い被検溶液の場合は、混入前の光センサー5の出力信号は0.0Vであることから、この出力信号の差が本実施の形態の被検溶液元来の混濁程度を示しているといえる。この値は図9を検量線として、タンパク質濃度に換算すると4〜5mg/dlに相当する。
一方、試薬を混入後300秒経過した時点の光センサー5の出力信号は、0.22Vで、0秒時点の出力信号との差は0.17Vとなる。図9を検量線として、この出力信号の差(0.17V)をタンパク質濃度に換算すると15mg/dlとなり、この濃度が予め計測された既知濃度に一致する。このことから、混濁が無い被検溶液から求めた図9の検量線を用いて、試薬混入前後の光センサー5の出力信号の差から混濁被検溶液のタンパク質濃度を正確に求められることが確認できた。
以上のように、試薬の混入前後の散乱光強度の差より、溶液濃度を算出することで、混濁等の影響が消去された正確な溶液濃度を求めることが可能になる。
【0037】
また、図12において、試薬の混入前、即ち−60〜0秒において、光センサー4の出力信号(透過光強度)は0.55Vである。一方、実施の形態1に用いたような混濁が無い透明な被検溶液の場合は、混入前の光センサー4の出力信号は0.6Vであることから、この相違は被検溶液の混濁によるものといえる。図12から、試薬混入前での光センサー4の出力信号が0.55V、混入後300秒経過した時点での出力信号が0.42Vであり、その比は0.76となる。図10を検量線として、この出力信号の比(0.76)をタンパク質濃度に換算すると15mg/dlとなり、この濃度は予め計測された既知濃度に一致する。このことから、図10を検量線として用いて、試薬混入前後の光センサー4の出力信号の比を求め、混濁が無い被検溶液から求めた図10を検量線として、タンパク質濃度に換算することで、混濁した被検溶液の正確なタンパク質濃度が求められることが確認できた。
【0038】
また、透過光強度の変化からタンパク質濃度を求める場合においては、上記の試薬のほかに、ビューレット試薬(酒石酸カリウムナトリウムと硫酸銅を水酸化ナトリウム溶液に溶解させた試薬)を用いることも可能である。ただし、この場合には、波長が540nm程度の光源を使用するのが好ましい。これを用いて、混濁した被検溶液を計測する場合でも、本実施の形態のように、混濁等の影響を受けず、正確に濃度を求めることが可能になる。
【0039】
《実施の形態3》
次に、図1および2に示した計測装置を用い、実施の形態1と同様の方法により、光センサー4および光センサー5の双方の出力信号を計測して両者を照合することにより、浮遊粒子、泡等による計測妨害の有無を検知する例を説明する。
被検溶液中に、浮遊粒子や泡が存在し、これらが略平行光2の光路に侵入すると、これらに略平行光2が強く散乱されて透過光強度および/または散乱光強度の正確な計測が妨害される。この場合、透過光強度は大きく減少し、一方、散乱光強度は光センサー5の視野角、および浮遊粒子や泡が光路中に存在する位置などによって、大きく減少する場合と増加する場合がある。
【0040】
これら浮遊粒子や泡による妨害が無い場合は、図9および10で示したように、散乱光強度の計測値と透過光強度の計測値には、一定の関係が存在する。例えば、被検溶液のタンパク質濃度が、15mg/dlの時、試薬混入前後の散乱光強度の差は0.17Vで、試薬混入前後の透過光強度の比は0.76である。ところが、上記のような妨害が存在すると、このような関係から外れた値が計測されることになる。
従って、試薬混入前後の光センサー4の計測値から図9の検量線にもとづいて求めたタンパク質濃度と、光センサー5の出力信号の計測値から図10の検量線にもとづいて求めたタンパク質濃度との、双方の濃度値が一致するか否かを照合することで、前記の妨害の有無を検知することができる。
【0041】
以上のように本実施の形態によれば、試薬混入前後の透過光強度および試薬混入前後の散乱光強度の双方を測定し、これらを照合することで、泡、未溶解の各種塩、ほこり、ゴミなどの浮遊粒子による妨害を検知して誤計測を防止できる。これにより、計測の信頼性を向上させることができ、その実用的効果は極めて大きく、計測および検査の高信頼化および省力化が可能になる。
【0042】
《実施の形態4》
次に、図1および2に示した計測装置におけるサンプルセルの汚損などによる光学窓の透過率の低下が生じた場合に、被検溶液と基準溶液についての双方の、光センサー4および/または光センサー5の出力信号を同条件で計測し、基準溶液の計測値により被検溶液の計測値を補正して、被検溶液中の特定成分の濃度を求める例について説明する。
サンプルセル3を長期間使用したような場合には、各種の残留物質が付着して、各光学窓の透過率が低下する。この場合、透過光強度の絶対値が低下するため、試薬混入前後の透過光強度の比の精度が低下し、試薬混入前後の散乱光強度の差は減少することになる。従って、これらの場合には、精度良く溶液濃度を求めることができない。
【0043】
このような長期間使用による光学窓の透過率低下の影響を、タンパク質濃度が既知の被検溶液(基準溶液)についての計測をすることで補正することができる。例えば、予め、タンパク質濃度が15mg/dlの基準溶液について計測する。この際、スルホサリチル酸試薬の混入前と混入後300秒経過後の散乱光強度の差が、0.15Vの場合は、次のように実施の形態1で得られた図9の検量線を補正する。即ち、図9では、タンパク質濃度が15mg/dlの時の上記散乱光強度の差は0.17Vであるため、図9の検量線より得られる濃度を0.17/0.15倍して補正した新たな検量線を用いて溶液濃度を求める。
上記のように、基準溶液の試薬混入前後の散乱光強度の変化を計測し、既知の検量線と照合することで、光学窓の透過率の低下の影響を補正した新たな検量線を求めることができる。これを用いることにより、光学窓の透過率が低下した場合でも、正確な濃度測定が可能となる。
【0044】
《実施の形態5》
実施の形態4で述べた光学窓の透過率の低下の影響を補正するための基準溶液として、特定成分を含有しない水を用いた例について説明する。
被検溶液が特定成分を含有しない水の場合は、試薬混入によって反応して水の光学特性を変化させる特定成分の濃度がゼロなので、実施の形態4で示したような散乱光強度の差は発生しない。そのため、補正に要する数値を算出することができない。そこで、サンプルセル3に水を入れた状態の透過光強度を計測する。例えば、この時の透過光強度が0.5Vの場合は、次のように補正する。図3、5および7より、試薬を混入前の透明な状態では透過光強度は0.6Vであるので、図9の検量線より得られた濃度を0.6/0.5倍する補正を行うことにより正確な濃度を求めることができる。
【0045】
上記のように、基準溶液として水を用いて透過光強度を計測することで、光学窓の透過率低下の影響を補正することができる。また、残留物質の付着具合が同等な場合には、透過光が出射する光学窓と、散乱光が出射する光学窓との透過率の低下が同じであるため、水に対する上記の透過光強度の低下から、散乱光強度の変化量を補正することもできる。
以上のように本実施の形態によれば、基準溶液として水を使用することができるため、簡単に光学窓の透過率の低下を補正することができる。特に、タンパク質水溶液を管理保管することが難しい家庭などにおいては、簡便なので実用的効果は極めて大きい。
【0046】
《実施の形態6》
次に、試薬混入前に被検溶液の旋光度を計測するとともに、試薬混入前後に被検溶液の透過光強度を計測し、これらの計測値から、タンパク質濃度とタンパク質以外の旋光性物質の濃度を確定する方法の例について詳細に説明する。
図13は本実施の形態の計測方法に基づく計測装置の模式図である。半導体レーザモジュールの光源1から、波長670nm、強度3.0mW、ビーム直径2.0mmの略平行光2を投射する。偏光子11は、紙面に平行な偏光成分の光のみを透過する。被検溶液を収容するサンプルセル12は、被検溶液に略平行光2の伝搬方向に磁場を印加できるようにソレノイドコイル13を巻いた構造になっており、実質光路長は10mmである。これは、被検溶液の光ファラデー効果を用いて、ソレノイドコイル13に流す電流を変調しながら制御することによって、略平行光2の偏光方向を変調しながら制御するものである。このように、被検溶液自身のファラデー効果によって、旋光度を計測する方式の基本原理は、特開平9−145605号公報に記載されている。
【0047】
試薬は注入口14からサンプルセル12に混入され、空気は通気口15から出入りする。検光子16は、紙面に垂直な偏光成分の光のみを透過するように配置されている。検光子16を透過した略平行光2を光センサー17で検出する。
コイルドライバー18により、ソレノイドコイル13に流す電流を制御し、信号発生器19により、ソレノイドコイル13に流す電流を変調する変調信号をコイルドライバー18に供給する。ロックインアンプ20により、ソレノイドコイル13の変調信号を参照信号として光センサー17の出力信号を位相敏感検波する。被検溶液の旋光度を計測する際は、コンピューター21により、ロックインアンプ20の出力信号がゼロになるように、コイルドライバー18に制御電流信号を供給する。
【0048】
本実施の形態の場合は、ソレノイドコイル13に、振幅0.001アンペア、周波数1.3kHzの変調電流を流している。これらによって、ロックインアンプ20の出力信号がゼロになる制御電流信号を見いだし、旋光度を算出する。ここでは、被検溶液中の旋光性物質であるタンパク質やグルコースによって生じた旋光度と、磁場印加による被検溶液の溶媒水のファラデー効果による偏光方向の回転角が一致する磁場を与える制御電流信号によって前記旋光度を求める方法を採った。
そして、ピペッタ22は、チューブ23を通じて、注入口14より、サンプルセル12中の被検溶液に試薬を所定量注入する。コンピューター21は、光源1およびピペッタ22を制御し、光センサー17の出力信号を解析する。
【0049】
上記の装置を用いて、尿を被検溶液としてグルコース濃度(尿糖値)と、尿タンパク濃度を検査する場合の動作は次の通りである。
まず、被検溶液をサンプルセル12へ導入する。コンピューター21で光源1とコイルドライバー18を動作させ、被検溶液の旋光度を計測する。
次に、コンピューター21でコイルドライバー18の動作を停止させ、同時に光センサー17の出力信号のモニターを開始する。次に、コンピューター21でピペッタ22を制御して、注入口14よりスルホサリチル酸試薬をサンプルセル12中の被検溶液へ混入する。この混入の前後の光センサー17の出力信号の変化を、透過光強度の変化と見なして、解析された試薬混入前後の透過光強度の比から、実施の形態1と同様な方法により、図10に相当する検量線を作製しておく。
【0050】
上記の計測の例として、尿糖値が100mg/dl、尿タンパク濃度が15mg/dlの尿を被検溶液として用いた場合の旋光度の計測値は、0.0034°であった。この波長(670nm)におけるグルコースの比旋光度は40°deg/cm・dl/kgであるので、計測された旋光度がすべてグルコースにより発現されていると仮定すると、グルコース濃度即ち尿糖値は85mg/dlと計算される。一方、透過光強度の比から求めたタンパク質濃度は15mg/dlであったので、タンパク質の比旋光度が−40°deg/cm・dl/kgであることから、タンパク質により発現された旋光度は−0.0006°と算出される。従って、グルコースにより発現された真の旋光度は前記の0.0034°から−0.0006°を差し引いた0.0040°となり、この旋光度に対応するグルコース濃度は100mg/dlと算出される。
【0051】
これらのことから、本実施の形態により、試薬混入前の被検溶液の旋光度と試薬混入前後の透過光強度の比を計測することにより、尿糖値と尿タンパク濃度を同時に正確に確定できることが確認できた。尚、前記タンパク質濃度(15mg/dl)の計測は、光センサー17の出力信号を透過光強度の信号と見なして、その試薬混入前後の値を計測し、予め作製しておいた前記検量線と照合することにより行った。
以上のように本実施の形態によれば、タンパク質濃度と、タンパク質以外の旋光性物質としてグルコースの濃度を同時に測定することができるので、尿を被検溶液とした場合に、特にその実用性が高い。その理由を以下に述べる。
【0052】
尿タンパク濃度が正常な場合は、尿中の旋光性物質としては、グルコースが支配的なので、尿の旋光度を計測することでおよその尿糖値を検査できる。しかし、尿タンパク濃度を旋光度計測以外の計測方式で求めることにより、より正確な尿検査ができる。なぜなら、グルコースとともに、タンパク質も旋光性物質であるため、グルコースより発現された旋光度と、タンパク質により発現された旋光度を加算した旋光度が尿の旋光度として計測されるからである。そこで、本実施の形態のように、旋光度の計測とともに、上記のように試薬混入前後の光学的物性変化からタンパク質濃度を求め、この濃度により、旋光度の計測結果を補正することにより、尿糖値と尿タンパク濃度を正確に確定することができる。
ちなみに、旋光度の計測前に試薬を混入すると、タンパク質成分が凝集あるいは着色するので、被検溶液中を光が透過しないことや、タンパク質が変性して旋光度を変化させることがあり、尿糖値と尿タンパク濃度を正確に測定できない。
【0053】
《実施の形態7》
次に、被検溶液のタンパク質濃度とタンパク質以外の旋光性物質の濃度とを同時に計測する他の例について詳細に説明する。
図14は本実施の形態による計測装置の模式図であり、図13の装置に光変調器24を付加したもので、光変調器24以外の符号は図13と同じである。光変調器24は、コンピューター21から指令があると、信号発生器19の変調周波数で、略平行光2を強度変調する。旋光度を計測している時は、コンピューター21の指令に基づき、変調は行わず、略平行光2をすべて透過している状態に固定しておく。
【0054】
本実施の形態では、旋光度は実施の形態6と同様に計測する。タンパク質濃度を計測する際は、ソレノイドコイル13には電流を流さず、コンピューター21の指令により、光変調器24により、略平行光2を強度変調する。この時も、ロックインアンプ20は、信号発生器19の出力信号を参照信号として、光センサー17の出力信号を位相敏感検波している。このロックインアンプ20の出力信号は、実質的に被検溶液の透過率を反映しているため、ロックインアンプ20の出力信号を透過光強度と見なせる。従って、コンピューター21がピペッタ22を制御して、注入口14よりスルホサリチル酸試薬をサンプルセル12へ混入して、この混入の前後のロックインアンプ20の出力信号の変化を解析することで、タンパク質濃度を正確に計測できる。計測されたタンパク質濃度と旋光度から、実施の形態6と同様にして、タンパク質以外の旋光性物質の濃度を確定することができる。
【0055】
尚、本実施の形態と実施の形態6ではいずれも、偏光子11と検光子16がクロスニコル配置にあるため、光センサー17に到達する光の強度は非常に小さい。従って、本実施の形態のように、略平行光2を強度変調し、光センサー17の出力信号を位相敏感検波して帯域を制限することで、信号対雑音比(S/N)を向上させる効果が非常に大きくなり、タンパク質濃度の測定精度が向上する。
以上のように本実施の形態により、略平行光2を変調することで、タンパク質濃度を高精度で計測できる。本実施の形態は、被検溶液が尿の時に、特にその実用性が高い。
また、上記本発明の実施の各形態においては、試薬を混入する場合、試薬を直接被検溶液にピペッタ等で注入する形態を示したが、被検溶液に試薬を滴下する形態でも同様の効果が得られる。
【0056】
【発明の効果】
以上のように本発明によれば、被検溶液元来の混濁や着色の影響、光学窓等の透過率低下の影響などを補正することができ、タンパク質などの特定成分の正確な濃度を求めることができる。また、計測可能な被検溶液の濃度範囲を拡大することができる。
その結果、被検溶液中の特定成分の濃度を高精度で求めることができ、しかも、高信頼性で実用性が高い省力化された溶液濃度の測定、とりわけ尿中のタンパク質濃度の測定が可能になる。
また、被検溶液中のタンパク質とタンパク質以外の旋光性物質の双方の濃度を求めることもでき、特に被検溶液が尿の場合、尿タンパク濃度と尿糖値を同時に正確に測定できるので、尿検査工程を大幅に簡略化でき、その実用的効果は極めて大きい。
【図面の簡単な説明】
【図1】 本発明による溶液濃度計測装置の第一の例の模式的な正面図である。
【図2】 上記溶液濃度計測装置の光学系の模式的な平面図である。
【図3】 上記溶液濃度計測装置により計測した第一例の被検溶液の透過光強度を示す図である。
【図4】 上記溶液濃度計測装置により計測した被検溶液の散乱光強度を示す図である。
【図5】 上記溶液濃度計測装置により計測した第二例の被検溶液の透過光強度を示す図である。
【図6】 上記溶液濃度計測装置により計測した被検溶液の散乱光強度を示す図である。
【図7】 上記溶液濃度計測装置により計測した第三例の被検溶液の透過光強度を示す図である。
【図8】 上記溶液濃度計測装置により計測した被検溶液の散乱光強度を示す図である。
【図9】 本発明により散乱光強度から尿タンパク濃度を求める検量線の例を示す図である。
【図10】 本発明により透過光強度から尿タンパク濃度を求める検量線の例を示す図である。
【図11】 前記溶液濃度計測装置により計測した懸濁被検溶液の散乱光強度を示す図である。
【図12】 前記溶液濃度計測装置により計測した懸濁被検溶液の透過光強度を示す図である。
【図13】 本発明による溶液濃度計測装置の第二の例の模式的な正面図である。
【図14】 本発明による溶液濃度計測装置の第三の例の模式的な正面図である。
【符号の説明】
1 光源
2 略平行光
3、12 サンプルセル
4、17 透過光を検知する光センサー(光センサー1)
5 散乱光を検知する光センサー(光センサー2)
6 注入口
7 22 ピペッタ
8、21 コンピューター
9 散乱光
10 被検溶液
11 偏光子
13 ソレノイドコイル
14 注入口
15 通気口
16 検光子
18 コイルドライバー
19 信号発生器
20 ロックインアンプ
23 チューブ
24 光変調器
[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method and an apparatus for measuring the concentration of a solute dissolved in a test solution, such as a protein concentration and a concentration of an optical rotatory substance.
[0002]
[Prior art]
  Conventional solution concentration measuring apparatuses include a spectroscope and liquid chromatography. As a urine test apparatus, there is a urine test apparatus in which urine is immersed in a test paper impregnated with a reagent, a color reaction of the urine is observed with a spectroscope or the like, and a urine component is tested.
  The test paper used here is prepared for each test item such as glucose and protein.
[0003]
  However, the above method has a problem that the apparatus becomes large-scale. In addition, the concentration range that can be measured is limited, and it is necessary to dilute a test solution that exceeds the limited concentration range, so that the process becomes complicated. Furthermore, there are cases where accurate measurement results cannot be obtained due to the turbidity of the test solution itself and the contamination of the optical window. In addition, if various particles, bubbles, etc. floating in the test solution are present in the optical path of the light used for measurement, this causes a problem of causing malfunction.
[0004]
[Problems to be solved by the invention]
  An object of the present invention is to solve the above-described problems, and to provide a solution concentration measuring device that is highly reliable, small in size, easy to maintain, and a measuring method that enables the device design. Another object of the present invention is to provide a means for enabling a simple and highly accurate urinalysis.
[0005]
[Means for Solving the Problems]
  In order to solve the above problems, the present invention is a method for measuring the concentration of a specific component in a test solution, which contains a reagent that changes the optical properties of the test solution due to the specific component.BeforeMeasure the transmitted light intensity and scattered light intensity of the test solution later, and mix the reagentPreviousDetermine the concentration of the specific component in the test solution in the low concentration range from the measured value of the scattered light intensity later, and mix the reagentPreviousA solution concentration measuring method is provided, wherein the concentration of the specific component in the test solution in a high concentration region is determined from the measured value of the transmitted light intensity later.
[0006]
  MaIn addition, by comparing the measured value of transmitted light intensity before and after mixing of the reagent with the measured value of scattered light intensity before and after mixing of the reagent, it is possible to detect the presence or absence of erroneous measurement due to suspended particles in the test solution. It is valid.
[0007]
  MaIn addition, for the reference solution having a known concentration and the test solution, at least one of transmitted light intensity and scattered light intensity before and after mixing of the reagent is measured under the same conditions, and the test solution is determined based on the measured value of the reference solution. It is effective to obtain the concentration of the specific component in the test solution by correcting the measured value.
  It is effective that the reference solution is water not containing the specific component.
[0008]
  Further, the present invention obtains the protein concentration of the test solution by the solution concentration measuring method, and obtains the optical rotation substance concentration in the test solution by measuring the optical rotation of the test solution before mixing the reagent. Then, a solution concentration measuring method is also provided, wherein the concentration of the optical rotatory substance other than the protein is determined from the protein concentration and the optical rotatory substance concentration.
[0010]
The present invention also detects a light source that irradiates the test solution with light, a sample cell that holds the test solution so that the light passes through the test solution, and light that has passed through the test solution. An optical sensor 1 that detects the scattered light generated when the light propagates through the test solution, and changes optical characteristics of only a specific component in the test solution to the test solution. And a computer for controlling the mixer and analyzing the output signal of the photosensor, and from the measured value of the output signal of the photosensor 1 before and after the reagent mixture, The concentration of the specific component in the test solution is obtained, and the concentration of the specific component in the test solution in a low concentration range is obtained from the measured value of the output signal of the photosensor 2 before and after mixing of the reagent. A solution concentration measuring device is also provided.
[0011]
  PreviousBy comparing the measured value of the output signal of the photosensor 1 before and after mixing the reagent with the measured value of the output signal of the photosensor 2 before and after mixing the reagent, erroneous measurement due to suspended particles in the test solution is performed. It is effective to detect the presence or absence.
[0013]
  Furthermore, a monochromatic light source that projects substantially parallel light, a polarizer that transmits only a polarized light component in a specific direction of the substantially parallel light, means for applying a magnetic field to the test solution, and magnetic field control that controls the magnetic field Means, a magnetic field modulation means for vibrationally modulating the magnetic field when controlling the magnetic field, an analyzer that transmits only a polarized component in a specific direction out of the light transmitted through the test solution, and the analyzer that has passed through the analyzer An optical sensor 3 that detects light; a lock-in amplifier that detects a phase-sensitive detection of an output signal of the optical sensor 3 using a vibration modulation signal of the magnetic field modulation means as a reference signal; a magnetic field control signal of the magnetic field control means; Calculate the optical rotation of the test solution based on the output signal of the amplifier The sample cell holds the test solution so that the light transmitted through the polarizer is transmitted and measured before and after mixing the reagent. The protein concentration of the test solution is determined from the measured value of the transmitted light intensity of the test solution, or the output signal of the photosensor 3 is regarded as the signal of the transmitted light, and the measured value of the output signal of the photosensor 3. It is also effective to determine the concentration of the optical rotatory substance other than the protein concentration and the protein in the test solution from the calculated optical rotation and the protein concentration.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
  As described above, the solution concentration measuring method of the present invention is a method for measuring the concentration of a specific component in a test solution, and includes a reagent that changes the optical characteristics of the test solution caused by the specific component. The transmitted light intensity and / or scattered light intensity of the test solution before and after is measured, and the concentration of the specific component in the test solution is obtained based on these measured values.
[0015]
  The reagent reacts only with a specific component whose concentration is to be measured in the test solution, causing discoloration, turbidity, etc., and causing an optical change of the degree corresponding to the concentration of the specific component in the test solution. Is. By mixing such a reagent into the test solution, the optical properties of the test solution can be changed, and the concentration of this specific component can be measured. For example, when urine is used as the test solution, the optical properties of the urine are changed by agglutinating the protein component by agglutinating the reagent, and the difference in scattered light intensity before and after mixing the reagent (scattered light intensity after mixing the reagent) -The protein in urine can be determined from the ratio of the scattered light intensity before mixing the reagent) and / or the ratio of the transmitted light intensity before and after mixing the reagent (transmitted light intensity after mixing the reagent / transmitted light intensity before mixing the reagent).
[0016]
  Furthermore, the solution concentration measuring apparatus of the present invention includes a light source that irradiates light to the test solution, a sample cell that holds the test solution so that the light passes through the test solution, and the test solution An optical sensor 1 for detecting light transmitted through the optical sensor and / or an optical sensor 2 arranged to detect scattered light generated when the light propagates in the test solution, and the test solution in the test solution A mixing machine that mixes a reagent that changes the optical characteristics of a test solution caused by a specific component in the solution; a computer that controls the mixing machine and analyzes an output signal of the optical sensor 1 and / or the optical sensor 2; The concentration of the specific component in the test solution is obtained from the measured value of the output signal of the photosensor 1 and / or the photosensor 2 before and after mixing of the reagent.
[0017]
  The concentration of a specific component in the test solution can be determined by measuring at least one of transmitted light intensity and scattered light intensity before and after mixing of the reagent by the solution concentration measuring method or apparatus according to the present invention. it can. Then, by measuring both the transmitted light intensity and the scattered light intensity, the following advantages are further added.
  First, from the measured value of scattered light intensity before and after mixing of the reagent, the concentration of the specific component in the test solution in a low concentration range is determined, and from the measured value of transmitted light intensity before and after mixing of the reagent, By determining the concentration of the specific component in the test solution, the concentration of the specific component can be determined with high accuracy for a test solution in a wider concentration range. The “high concentration” and “low concentration” in the present invention will be described later.
[0018]
  Furthermore, by comparing the measured value of transmitted light intensity before and after mixing of the reagent with the measured value of scattered light intensity before and after mixing of the reagent, bubbles, undissolved various salts, dust, dust, etc. in the test solution The presence or absence of erroneous measurement due to suspended particles can be detected, and erroneous measurement and malfunction of the apparatus can be prevented.
  In addition, for the reference solution having a known concentration and the test solution, the transmitted light intensity before and after mixing the reagent and / or the scattered light intensity before and after mixing the reagent are measured under the same conditions, and the measured value of the reference solution, By correcting the measurement value of the test solution to obtain the concentration of the specific component in the test solution, the influence of the transmittance reduction of the optical window layer and the like is eliminated, and more accurate measurement is possible. Become. In this case, water that does not contain the specific component can be used as a simple reference solution.
[0019]
  Furthermore, in the present invention, the optical rotation of the test solution is measured before mixing the reagent, and the protein concentration of the test solution is obtained by any one of the solution concentration measuring methods according to the present invention, and the protein concentration And the optical rotation can determine the concentration of the protein and the concentration of the optical rotatory substance other than the protein. In order to simultaneously measure the degree of the protein in the test solution and the optical rotatory substance other than the protein by this method, the following apparatus can be used.
[0020]
  That is, a monochromatic light source that projects substantially parallel light, a polarizer that transmits only a polarized light component in a specific direction among the substantially parallel light, and a sample that holds a test solution so that light transmitted through the polarizer is transmitted. A cell, a means for applying a magnetic field to the test solution, a magnetic field control means for controlling the magnetic field, a magnetic field modulation means for vibration-modulating the magnetic field when controlling the magnetic field, and transmitted through the test solution An analyzer that transmits only a polarized light component in a specific direction of light, an optical sensor that detects light transmitted through the analyzer, and an output signal of the optical sensor as a reference signal using a vibration modulation signal of the magnetic field modulation means as a reference signal A lock-in amplifier for sensitive detection; a means for calculating the optical rotation of the test solution based on a magnetic field control signal of the magnetic field control means and an output signal of the lock-in amplifier; An apparatus comprising: a mixing machine that mixes a reagent that changes only the optical properties of a specific component in the test solution into the test solution; and a computer that controls the mixing machine and analyzes an output signal of the optical sensor. It is.
[0021]
  From the measured value of the transmitted light intensity before and after mixing of the reagent measured by this apparatus, the protein concentration of the test solution is obtained, and the protein concentration and the protein concentration other than the protein are calculated from the calculated optical rotation and the protein concentration. The concentration of the optical rotatory substance in the test solution is determined. In this case, it is possible to measure the protein concentration of the test solution from the measurement of the output signal of the photosensor by regarding the output signal of the photosensor as the signal of the transmitted light.
[0022]
  Furthermore, in addition to the above-described device, by providing means for modulating the substantially parallel light, when the reagent is mixed into the test solution and the output signal of the photosensor is measured, the lock-in amplifier is referred to The output signal of the lock-in amplifier before and after mixing of the reagent is obtained by phase-sensitive detection of the output signal of the optical sensor using the signal as the modulation signal of the substantially parallel light and regarding the output signal of the lock-in amplifier as the signal of the transmitted light. The protein concentration of the test solution can be obtained from the measured value of the signal, and the protein concentration and the concentration of the optical rotatory substance in the test solution other than the protein can be determined from the optical rotation and the protein concentration.
[0023]
  By using the solution concentration measuring method or solution concentration measuring apparatus according to the present invention as described above, industrial fluids such as urine and other body fluids such as cerebrospinal fluid, serum, plasma and saliva, foods such as dairy products, sake and vinegar, and culture solutions. The concentration of the specific component contained in the test solution such as the solution and the artificial dialysis solution or its waste solution can be determined. Specific substances whose concentration is to be measured in these test solutions include various proteins such as hormones and enzymes, lipids such as cholesterol, viruses, and bacteria. Moreover, as a reagent used when calculating | requiring the density | concentration of these specific substances, acidic solutions, antibody solutions, etc., such as a trichloroacetic acid and a sulfosalicylic acid, can be used.
[0024]
  Further, the solution concentration measuring method or the solution concentration measuring apparatus according to the present invention described above can expand the measurable concentration range of the test solution, so that the accurate concentration of the specific component such as protein in the test solution can be easily obtained. It can be measured. Furthermore, after measuring the optical rotation of the test solution, the protein concentration is measured by mixing the reagent, whereby the protein concentration and the optical rotatory substance other than protein such as glucose can be determined simultaneously. Therefore, the solution concentration measuring method or the solution concentration measuring apparatus according to the present invention is particularly useful when testing by measuring urine protein concentration or urine sugar value using urine as a test solution, The accuracy can be improved and the inspection process can be greatly simplified.
  Hereinafter, embodiments of the present invention will be described in detail with specific examples.
[0025]
Embodiment 1
  Measure transmitted light intensity and / or scattered light intensity before and after mixing a reagent that changes the optical properties of the test solution due to a specific component contained in the test solution into the test solution. An example of obtaining the concentration of the specific component in the test solution from the above will be described in detail below.
[0026]
  FIG. 1 is a front view schematically showing the configuration of the solution concentration measuring apparatus, and FIG. 2 is a plan view schematically showing only the optical system of FIG. 1 and 2, reference numeral 1 denotes a light source composed of a semiconductor laser module, which projects substantially parallel light 2 having a wavelength of 780 nm, an intensity of 3.0 mW, and a beam diameter of 2.0 mm. The sample cell 3 is a rectangular parallelepiped container made of glass and having an opening opened at the top, a bottom surface of 10 × 10 mm and a height of 50 mm, and a side surface is a transparent optical window. The sample cell 3 can irradiate the test solution 10 accommodated therein with the substantially parallel light 2 and can extract transmitted light and scattered light 9 to the outside. Transmitted light and scattered light are detected by an optical sensor 4 that detects light transmitted through the test solution 10 and an optical sensor 5 that detects scattered light 9 generated when the light propagates through the test solution, respectively. The inlet 6 for injecting the reagent is located at the bottom of the sample cell 3. A predetermined amount of reagent is injected into the test solution in the sample cell 3 through the injection port 6 by the pipettor 7. The computer 8 controls the light source 1 and the pipetter 7 and analyzes the output signals of the optical sensors 4 and 5.
[0027]
  The operation in the case of examining the urine protein concentration using urine as a test solution using the above solution concentration measuring apparatus is as follows.
  First, the test solution 10 is introduced into the sample cell 3. The computer 8 operates the light source 1 and starts monitoring the output signals of the optical sensors 4 and 5 at the same time. Next, the computer 8 controls the pipetter 7 to introduce a sulfosalicylic acid reagent (a reagent in which sodium sulfate is dissolved in a 2-hydroxy-5-sulfobenzoic acid aqueous solution) into the sample cell 3 through the inlet 6. When the sulfosalicylic acid reagent is mixed into the test solution, the protein components aggregate to make the test solution 10 cloudy, the transmitted light intensity decreases, and the scattered light intensity increases. By analyzing the measured values of the output signals of the optical sensors 4 and 5 before and after mixing of the reagent, the protein concentration is obtained.
[0028]
  FIGS. 3 and 4 show the transmitted light intensity and scattered light intensity measured by the above method using the test solution 10 having a protein concentration of 2 mg / dl, that is, the output signals of the optical sensors 4 and 5, respectively. Similarly, FIGS. 5 and 6 show output signals when a test solution with a protein concentration of 15 mg / dl is used, and FIG. 7 shows output signals when a test solution with a protein concentration of 100 mg / dl is used. And 8. 3 to 8, the horizontal axis represents the elapsed time (seconds) after mixing the reagent, and shows the intensity change of transmitted light or scattered light from 60 seconds before mixing to 300 seconds after mixing. 3, 5 and 7, it can be seen that the intensity of the transmitted light (the output signal of the optical sensor 4) decreases as the protein concentration increases. In addition, it can be seen from FIGS. 4, 6 and 8 that the intensity of the scattered light (the output signal of the optical sensor 5) increases as the protein concentration increases.
[0029]
  FIGS. 9 and 10 show the relationship between the change in scattered light intensity, the change in transmitted light intensity, and the protein concentration, respectively. In FIG. 9, the vertical axis indicates the difference between the scattered light intensity after 300 seconds from the mixing of the reagent and the scattered light intensity before mixing (scattered light intensity after mixing the reagent−scattered light intensity before mixing the reagent). In FIG. 10, the ratio between the transmitted light intensity before mixing the reagent and the transmitted light intensity after 300 seconds from mixing (transmitted light intensity after mixing the reagent / transmitted light intensity before mixing the reagent) is shown on the vertical axis. 9 and 10 show the results of measurement by adding urine having protein concentrations of 0, 5, 30, and 60 mg / dl as test solutions in addition to the test solution. In these cases, all of the measured test solutions were optically transparent as much as water before the reagent was mixed, and transmitted light intensity and scattered light intensity were the same as water. Therefore, the correlation shown in FIG. 9 and FIG. 10 obtained from these can be used as a standard calibration curve when measuring the protein concentration in urine.
[0030]
  In FIG. 9, each measured value is smoothly connected and indicated by a solid line, and the protein concentration changes linearly with respect to the amount of change in scattered light intensity (difference in scattered light intensity before and after mixing of the reagent) 0-15 mg / dl The straight line connecting the actual measurement values in the area is extended with a dotted line. As is apparent from the solid line and the dotted line, the solid line and the dotted line overlap each other up to a protein concentration of about 15 mg / dl, and the amount of change in scattered light intensity is proportional to the protein concentration.
  However, as the concentration becomes higher than this, actually measured values lower than the proportional relationship are shown. This is because when the protein concentration increases and the probability that light is scattered increases, the probability that the light is scattered again increases from the point where the scattered light is generated to the outside of the sample cell. This is because the probability that the light will reach decreases. Therefore, when calculating the concentration from the change in the scattered light intensity, it is possible to obtain a more accurate concentration in a low concentration region (about 15 mg / dl or less) where linearity can be ensured.
[0031]
  In FIG. 10, the horizontal axis represents the protein concentration, and the vertical axis (logarithmic display) represents the ratio of transmitted light intensity before and after the reagent mixing. Each measured value was smoothly connected and indicated by a solid line, and a straight line connecting the actually measured values at a protein concentration of 15 to 100 mg / dl changing linearly was extended and indicated by a dotted line. As shown in FIG. 10, when the protein concentration is as low as 2 mg / dl or 5 mg / dl, it may deviate from this dotted line. This is because the rate of change is too small compared to the total output signal and is easily affected by various types of noise, as is clear when FIG. 3 is compared with FIGS. Therefore, when calculating the protein concentration from the measured value of transmitted light intensity, it is more desirable that the test solution is in a high concentration range (about 15 mg / dl or more) in order to avoid the influence of various noises. I understand.
[0032]
  As described above, the concentration of the specific component of the test solution can be obtained by measuring the transmitted light intensity before and after mixing the reagent or the scattered light intensity before and after mixing the reagent.
  Furthermore, by measuring both the above intensities, the solution concentration is calculated from the measured value of the scattered light intensity for the low concentration test solution, and the transmitted light intensity is measured for the high concentration test solution. By calculating the solution concentration from the value, the concentration range of the test solution that can be measured with substantially high accuracy, that is, the dynamic range can be expanded.
  As a result, steps such as diluting a high-concentration test solution, which have been necessary in the past, are no longer necessary, and practical effects effective for high accuracy, efficiency, and labor saving of measurement and inspection can be enhanced.
  In the present embodiment, the solution concentration is obtained from the measured values of transmitted light intensity and scattered light intensity immediately before mixing of the reagent and at the time when 300 seconds have elapsed, but this time difference depends on the characteristics of the measuring device, the test solution, the reagent, and the like. What is necessary is just to set suitably according to it.
[0033]
  In the present embodiment, the low concentration region is about 15 mg / dl or less, the high concentration region is about 15 mg / dl or more, the scattered light intensity is measured in the low concentration region, and the transmitted light intensity is measured in the high concentration region. Accurate results can be obtained.
  However, the low concentration range and the high concentration range in the present embodiment differ depending on various factors such as the optical path length of the sample cell 3, the propagation distance of the scattered light 9 in the test solution, and the arrangement of the optical system. It is not limited to a numerical range.
  Therefore, “low concentration” in the present invention refers to a concentration range corresponding to a portion having linearity in a graph showing the relationship between the concentration of a specific component of a test solution and the change in scattered light intensity (FIG. 9). “High concentration” refers to a concentration range corresponding to a portion having linearity in a graph showing the relationship between the concentration of a specific component of a test solution and the ratio of transmitted light intensity (FIG. 10). These can be determined in advance by those skilled in the art before carrying out the method according to the invention.
[0034]
  If the optical path length of the transmitted light is actually made longer than 10 mm, the transmitted light intensity can be measured with high accuracy even at a concentration of 15 mg / dl or less.
  However, when the optical path length is increased in this way, the output signal of the optical sensor 4 becomes too small in the high concentration range (about 10%).-FourV) It becomes difficult to obtain the concentration. Furthermore, if the optical path length is increased, the scale of the entire apparatus inevitably increases, which is not preferable in practice.
  As described above, according to the present invention, when the configuration and scale of the apparatus are subject to certain restrictions, by using both scattered light and transmitted light, high precision and low density can be obtained with high accuracy. The concentration can be measured and the dynamic range can be expanded.
[0035]
<< Embodiment 2 >>
  Next, an example in which the concentration of a specific component is determined using urine that is turbid as a result of precipitation of various salts and the like using the measurement device of FIGS. 1 and 2 will be described in detail.
  First, turbid urine having a protein concentration of 15 mg / dl is introduced into the sample cell 3 as the test solution 10, and the output of the optical sensor 4 and / or the optical sensor 5 before and after the reagent mixing is performed in the same manner as in the first embodiment. Observe signal changes.
  FIGS. 11 and 12 show changes with time in the output signals of the optical sensors 5 and 4 before and after the reagent mixing, respectively. These figures show the change in the output signal from 60 seconds before mixing the reagent to 300 seconds after mixing, as in FIGS.
[0036]
  As is apparent from FIG. 11, the output signal (scattered light intensity) of the optical sensor 5 before the reagent is mixed, that is, between -60 and 0 seconds is about 0.05V. In the case of a test solution having no turbidity as used in the first embodiment, the output signal of the optical sensor 5 before mixing is 0.0 V. Therefore, the difference between the output signals is the test signal of the present embodiment. It can be said that it shows the original turbidity of the solution. This value corresponds to 4 to 5 mg / dl in terms of protein concentration using FIG. 9 as a calibration curve.
  On the other hand, the output signal of the optical sensor 5 at the time when 300 seconds have elapsed after mixing the reagent is 0.22 V, and the difference from the output signal at the time of 0 seconds is 0.17 V. When the difference (0.17 V) of this output signal is converted into the protein concentration using FIG. 9 as a calibration curve, it becomes 15 mg / dl, and this concentration matches the known concentration measured in advance. From this, it is confirmed that the protein concentration of the turbid test solution can be accurately obtained from the difference in the output signal of the optical sensor 5 before and after the reagent mixing, using the calibration curve of FIG. 9 obtained from the test solution having no turbidity. did it.
  As described above, by calculating the solution concentration from the difference in scattered light intensity before and after mixing of the reagent, it is possible to obtain an accurate solution concentration in which the influence of turbidity or the like is eliminated.
[0037]
  In FIG. 12, the output signal (transmitted light intensity) of the optical sensor 4 is 0.55 V before the reagent is mixed, that is, between -60 and 0 seconds. On the other hand, in the case of a transparent test solution having no turbidity as used in the first embodiment, the output signal of the photosensor 4 before mixing is 0.6 V, so this difference is due to the turbidity of the test solution. It can be said that. From FIG. 12, the output signal of the optical sensor 4 before mixing the reagent is 0.55 V, the output signal when 300 seconds have passed after mixing is 0.42 V, and the ratio is 0.76. When the ratio (0.76) of this output signal is converted to the protein concentration using FIG. 10 as a calibration curve, it becomes 15 mg / dl, and this concentration matches the known concentration measured in advance. From this, using FIG. 10 as a calibration curve, the ratio of the output signal of the optical sensor 4 before and after mixing of the reagent is obtained, and converted to the protein concentration using FIG. 10 obtained from the test solution without turbidity as the calibration curve. Thus, it was confirmed that an accurate protein concentration of the turbid test solution was obtained.
[0038]
  In addition, when determining the protein concentration from the change in transmitted light intensity, it is also possible to use a burette reagent (a reagent in which potassium sodium tartrate and copper sulfate are dissolved in a sodium hydroxide solution) in addition to the above-mentioned reagents. is there. However, in this case, it is preferable to use a light source having a wavelength of about 540 nm. Even when a turbid test solution is measured using this, the concentration can be accurately obtained without being affected by turbidity or the like as in the present embodiment.
[0039]
<< Embodiment 3 >>
  Next, by using the measurement apparatus shown in FIGS. 1 and 2, the output signals of both the optical sensor 4 and the optical sensor 5 are measured by the same method as in the first embodiment, and both are collated, thereby floating particles. An example of detecting the presence or absence of measurement interference due to bubbles or the like will be described.
  When suspended particles and bubbles are present in the test solution and they enter the optical path of the substantially parallel light 2, the substantially parallel light 2 is strongly scattered by them, and the transmitted light intensity and / or the scattered light intensity is accurately measured. Is disturbed. In this case, the transmitted light intensity is greatly reduced, while the scattered light intensity may be greatly reduced or increased depending on the viewing angle of the optical sensor 5 and the position where suspended particles or bubbles are present in the optical path.
[0040]
  When there is no obstruction by these suspended particles or bubbles, as shown in FIGS. 9 and 10, there is a certain relationship between the measured value of scattered light intensity and the measured value of transmitted light intensity. For example, when the protein concentration of the test solution is 15 mg / dl, the difference in scattered light intensity before and after mixing of the reagent is 0.17 V, and the ratio of transmitted light intensity before and after mixing of the reagent is 0.76. However, if there is an interference as described above, a value deviating from such a relationship will be measured.
  Therefore, the protein concentration determined based on the calibration curve of FIG. 9 from the measured value of the optical sensor 4 before and after the reagent mixing, and the protein concentration determined based on the calibration curve of FIG. 10 from the measured value of the output signal of the optical sensor 5 The presence or absence of the interference can be detected by checking whether or not the two density values match.
[0041]
  As described above, according to the present embodiment, by measuring both the transmitted light intensity before and after mixing the reagent and the scattered light intensity before and after mixing the reagent, and collating them, bubbles, various undissolved salts, dust, Detection of interference caused by suspended particles such as garbage can prevent erroneous measurement. As a result, the reliability of measurement can be improved, and its practical effect is extremely large, and high reliability and labor saving of measurement and inspection can be achieved.
[0042]
<< Embodiment 4 >>
  Next, when the transmittance of the optical window is reduced due to contamination of the sample cell in the measurement apparatus shown in FIGS. 1 and 2, the optical sensor 4 and / or the light for both the test solution and the reference solution are used. An example will be described in which the output signal of the sensor 5 is measured under the same conditions, the measurement value of the test solution is corrected with the measurement value of the reference solution, and the concentration of the specific component in the test solution is obtained.
  When the sample cell 3 is used for a long period of time, various residual substances are attached, and the transmittance of each optical window is lowered. In this case, since the absolute value of the transmitted light intensity decreases, the accuracy of the ratio of the transmitted light intensity before and after mixing of the reagent decreases, and the difference in scattered light intensity before and after mixing of the reagent decreases. Therefore, in these cases, the solution concentration cannot be obtained with high accuracy.
[0043]
  The influence of the decrease in transmittance of the optical window due to such long-term use can be corrected by measuring a test solution (reference solution) having a known protein concentration. For example, a reference solution having a protein concentration of 15 mg / dl is measured in advance. At this time, when the difference in scattered light intensity before mixing of the sulfosalicylic acid reagent and after 300 seconds from mixing is 0.15 V, the calibration curve of FIG. 9 obtained in Embodiment 1 is corrected as follows. To do. That is, in FIG. 9, since the difference in the scattered light intensity when the protein concentration is 15 mg / dl is 0.17 V, the concentration obtained from the calibration curve in FIG. 9 is corrected by multiplying by 0.17 / 0.15. The solution concentration is determined using the new calibration curve.
  As described above, a change in the scattered light intensity before and after mixing of the reagent in the reference solution is measured and collated with a known calibration curve to obtain a new calibration curve that corrects the effect of a decrease in the transmittance of the optical window. Can do. By using this, accurate density measurement is possible even when the transmittance of the optical window is lowered.
[0044]
<< Embodiment 5 >>
  An example in which water that does not contain a specific component is used as a reference solution for correcting the influence of the decrease in the transmittance of the optical window described in the fourth embodiment will be described.
  In the case where the test solution does not contain a specific component, the concentration of the specific component that reacts to change the optical characteristics of the water by reacting with the reagent is zero, so the difference in scattered light intensity as shown in Embodiment 4 is Does not occur. Therefore, the numerical value required for correction cannot be calculated. Therefore, the transmitted light intensity in a state where water is put into the sample cell 3 is measured. For example, when the transmitted light intensity at this time is 0.5 V, the correction is performed as follows. 3, 5 and 7, since the transmitted light intensity is 0.6 V in the transparent state before mixing the reagent, the correction obtained by multiplying the concentration obtained from the calibration curve of FIG. 9 by 0.6 / 0.5 is made. By doing so, an accurate concentration can be obtained.
[0045]
  As described above, by measuring the transmitted light intensity using water as the reference solution, it is possible to correct the influence of the decrease in the transmittance of the optical window. In addition, when the degree of adhesion of the residual material is the same, the decrease in the transmittance of the optical window from which the transmitted light is emitted and the optical window from which the scattered light is emitted are the same. The amount of change in scattered light intensity can also be corrected from the decrease.
  As described above, according to the present embodiment, since water can be used as the reference solution, it is possible to easily correct the decrease in the transmittance of the optical window. Particularly in homes where it is difficult to manage and store protein aqueous solutions, the practical effect is extremely great because of its simplicity.
[0046]
<< Embodiment 6 >>
  Next, the optical rotation of the test solution is measured before mixing the reagent, and the transmitted light intensity of the test solution is measured before and after mixing the reagent. From these measured values, the protein concentration and the concentration of the optical rotatory substance other than the protein are measured. An example of a method for confirming will be described in detail.
  FIG. 13 is a schematic diagram of a measurement apparatus based on the measurement method of the present embodiment. A substantially parallel light 2 having a wavelength of 670 nm, an intensity of 3.0 mW, and a beam diameter of 2.0 mm is projected from the light source 1 of the semiconductor laser module. The polarizer 11 transmits only light having a polarization component parallel to the paper surface. The sample cell 12 containing the test solution has a structure in which a solenoid coil 13 is wound around the test solution so that a magnetic field can be applied in the propagation direction of the substantially parallel light 2, and the actual optical path length is 10 mm. This is to control the polarization direction of the substantially parallel light 2 by modulating the current flowing through the solenoid coil 13 by using the optical Faraday effect of the test solution. Thus, the basic principle of the method for measuring the optical rotation based on the Faraday effect of the test solution itself is described in Japanese Patent Laid-Open No. 9-145605.
[0047]
  The reagent is mixed into the sample cell 12 from the inlet 14, and the air enters and exits from the vent 15. The analyzer 16 is disposed so as to transmit only light having a polarization component perpendicular to the paper surface. The substantially parallel light 2 transmitted through the analyzer 16 is detected by the optical sensor 17.
  The coil driver 18 controls the current that flows through the solenoid coil 13, and the signal generator 19 supplies a modulation signal that modulates the current that flows through the solenoid coil 13 to the coil driver 18. The lock-in amplifier 20 performs phase sensitive detection of the output signal of the optical sensor 17 using the modulation signal of the solenoid coil 13 as a reference signal. When measuring the optical rotation of the test solution, the computer 21 supplies a control current signal to the coil driver 18 so that the output signal of the lock-in amplifier 20 becomes zero.
[0048]
  In the case of the present embodiment, a modulation current having an amplitude of 0.001 ampere and a frequency of 1.3 kHz is passed through the solenoid coil 13. As a result, a control current signal at which the output signal of the lock-in amplifier 20 becomes zero is found, and the optical rotation is calculated. Here, a control current signal that gives a magnetic field in which the optical rotation generated by protein or glucose, which is an optical rotatory substance in the test solution, matches the rotation angle of the polarization direction due to the Faraday effect of the solvent water of the test solution by applying a magnetic field The method for obtaining the optical rotation was used.
  Then, the pipetter 22 injects a predetermined amount of reagent into the test solution in the sample cell 12 from the injection port 14 through the tube 23. The computer 21 controls the light source 1 and the pipetter 22 and analyzes the output signal of the optical sensor 17.
[0049]
  The operation in the case of examining glucose concentration (urine sugar value) and urine protein concentration using urine as a test solution using the above apparatus is as follows.
  First, the test solution is introduced into the sample cell 12. The computer 21 operates the light source 1 and the coil driver 18 to measure the optical rotation of the test solution.
  Next, the operation of the coil driver 18 is stopped by the computer 21 and simultaneously the monitoring of the output signal of the optical sensor 17 is started. Next, the pipette 22 is controlled by the computer 21, and the sulfosalicylic acid reagent is mixed into the test solution in the sample cell 12 from the inlet 14. The change in the output signal of the optical sensor 17 before and after the mixing is regarded as a change in the transmitted light intensity, and the ratio of the transmitted light intensity before and after the mixed reagent is analyzed by the same method as in the first embodiment, as shown in FIG. A calibration curve corresponding to is prepared.
[0050]
  As an example of the above measurement, the measured value of the optical rotation when urine having a urine sugar value of 100 mg / dl and a urine protein concentration of 15 mg / dl was used as a test solution was 0.0034 °. Since the specific rotation of glucose at this wavelength (670 nm) is 40 ° deg / cm · dl / kg, assuming that all the measured rotations are expressed by glucose, the glucose concentration, that is, the urine sugar value is 85 mg. / Dl. On the other hand, since the protein concentration determined from the ratio of transmitted light intensity was 15 mg / dl, the specific rotation of the protein was −40 ° deg / cm · dl / kg, so the optical rotation expressed by the protein was Calculated as -0.0006 °. Therefore, the true optical rotation expressed by glucose is 0.0040 ° obtained by subtracting −0.0006 ° from the above 0.0034 °, and the glucose concentration corresponding to this optical rotation is calculated as 100 mg / dl.
[0051]
   Therefore, according to the present embodiment, the urine sugar value and the urine protein concentration can be accurately determined simultaneously by measuring the ratio between the optical rotation of the test solution before mixing the reagent and the transmitted light intensity before and after mixing the reagent. Was confirmed. The protein concentration (15 mg / dl) is measured by regarding the output signal of the optical sensor 17 as a transmitted light intensity signal, measuring values before and after mixing the reagent, and the calibration curve prepared in advance. This was done by matching.
  As described above, according to the present embodiment, the protein concentration and the glucose concentration as an optical rotatory substance other than protein can be measured simultaneously. Therefore, when urine is used as a test solution, its practicality is particularly good. high. The reason is described below.
[0052]
  When the urinary protein concentration is normal, glucose is dominant as the optical rotatory substance in urine, so the approximate urinary sugar level can be examined by measuring the optical rotation of urine. However, a more accurate urine test can be performed by obtaining the urine protein concentration by a measurement method other than the optical rotation measurement. This is because, together with glucose, protein is also an optical rotatory substance, and thus the optical rotation obtained by adding the optical rotation expressed from glucose and the optical rotation expressed by protein is measured as the optical rotation of urine. Therefore, as in the present embodiment, along with the measurement of the optical rotation, the protein concentration is obtained from the change in the optical physical properties before and after mixing with the reagent as described above, and the measurement result of the optical rotation is corrected by this concentration, thereby The sugar level and urine protein concentration can be accurately determined.
  By the way, if a reagent is mixed before measuring the optical rotation, the protein component will aggregate or color, so light may not pass through the test solution, and protein may denature and change the optical rotation. Value and urine protein concentration cannot be measured accurately.
[0053]
<< Embodiment 7 >>
  Next, another example of simultaneously measuring the protein concentration of the test solution and the concentration of the optical rotatory substance other than protein will be described in detail.
  FIG. 14 is a schematic diagram of a measuring apparatus according to the present embodiment, in which an optical modulator 24 is added to the apparatus of FIG. When instructed by the computer 21, the optical modulator 24 intensity-modulates the substantially parallel light 2 at the modulation frequency of the signal generator 19. When the optical rotation is being measured, the modulation is not performed based on a command from the computer 21 and the substantially parallel light 2 is completely transmitted.
[0054]
  In the present embodiment, the optical rotation is measured as in the sixth embodiment. When measuring the protein concentration, no current is passed through the solenoid coil 13, and the intensity of the substantially parallel light 2 is modulated by the light modulator 24 according to a command from the computer 21. Also at this time, the lock-in amplifier 20 performs phase-sensitive detection of the output signal of the optical sensor 17 using the output signal of the signal generator 19 as a reference signal. Since the output signal of the lock-in amplifier 20 substantially reflects the transmittance of the test solution, the output signal of the lock-in amplifier 20 can be regarded as the transmitted light intensity. Therefore, the computer 21 controls the pipetter 22, mixes the sulfosalicylic acid reagent into the sample cell 12 from the injection port 14, and analyzes the change in the output signal of the lock-in amplifier 20 before and after the mixing, so that the protein concentration Can be measured accurately. From the measured protein concentration and optical rotation, the concentration of the optical rotatory substance other than protein can be determined in the same manner as in the sixth embodiment.
[0055]
  In both the present embodiment and the sixth embodiment, since the polarizer 11 and the analyzer 16 are in a crossed Nicols arrangement, the intensity of light reaching the optical sensor 17 is very small. Therefore, as in this embodiment, the intensity of the substantially parallel light 2 is modulated, and the output signal of the optical sensor 17 is phase-sensitively detected to limit the band, thereby improving the signal-to-noise ratio (S / N). The effect becomes very large and the measurement accuracy of protein concentration is improved.
  As described above, according to the present embodiment, the protein concentration can be measured with high accuracy by modulating the substantially parallel light 2. This embodiment is particularly useful when the test solution is urine.
  In each of the embodiments of the present invention described above, when a reagent is mixed, the reagent is directly injected into the test solution with a pipetter or the like. Is obtained.
[0056]
【The invention's effect】
  As described above, according to the present invention, it is possible to correct the original turbidity and coloring effect of the test solution, the influence of the transmittance decrease of the optical window, etc., and to obtain the exact concentration of a specific component such as protein. be able to. In addition, the measurable concentration range of the test solution can be expanded.
  As a result, it is possible to determine the concentration of a specific component in a test solution with high accuracy, and to measure a highly reliable and practical and labor-saving solution concentration, especially the protein concentration in urine. become.
  It is also possible to determine the concentrations of both proteins and optically rotatory substances other than proteins in the test solution. Especially when the test solution is urine, the urine protein concentration and urinary sugar level can be accurately measured simultaneously. The inspection process can be greatly simplified, and its practical effect is extremely large.
[Brief description of the drawings]
FIG. 1 is a schematic front view of a first example of a solution concentration measuring apparatus according to the present invention.
FIG. 2 is a schematic plan view of an optical system of the solution concentration measuring apparatus.
FIG. 3 is a diagram showing transmitted light intensity of a test solution of the first example measured by the solution concentration measuring device.
FIG. 4 is a diagram showing scattered light intensity of a test solution measured by the solution concentration measuring device.
FIG. 5 is a diagram showing transmitted light intensity of a test solution of a second example measured by the solution concentration measuring device.
FIG. 6 is a diagram showing scattered light intensity of a test solution measured by the solution concentration measuring device.
FIG. 7 is a diagram showing transmitted light intensity of a test solution of a third example measured by the solution concentration measuring device.
FIG. 8 is a diagram showing the scattered light intensity of the test solution measured by the solution concentration measuring apparatus.
FIG. 9 is a diagram showing an example of a calibration curve for obtaining urine protein concentration from scattered light intensity according to the present invention.
FIG. 10 is a diagram showing an example of a calibration curve for obtaining urinary protein concentration from transmitted light intensity according to the present invention.
FIG. 11 is a diagram showing scattered light intensity of a suspension test solution measured by the solution concentration measuring device.
FIG. 12 is a diagram showing transmitted light intensity of a suspension test solution measured by the solution concentration measuring device.
FIG. 13 is a schematic front view of a second example of the solution concentration measuring apparatus according to the present invention.
FIG. 14 is a schematic front view of a third example of the solution concentration measuring apparatus according to the present invention.
[Explanation of symbols]
      1 Light source
      2 Nearly parallel light
      3, 12 sample cells
      4, 17 Optical sensor for detecting transmitted light (Photosensor 1)
      5 Light sensor to detect scattered light (light sensor 2)
      6 Inlet
      7 22 Pipetta
      8, 21 Computer
      9 Scattered light
    10 Test solution
    11 Polarizer
    13 Solenoid coil
    14 Inlet
    15 Vent
    16 Analyzer
    18 Coil driver
    19 Signal generator
    20 Lock-in amplifier
    23 tubes
    24 Optical modulator

Claims (8)

被検溶液中の特定成分の濃度を計測する方法であって、前記特定成分に起因する被検溶液の光学特性を変化させる試薬を混入する前後の前記被検溶液の透過光強度および散乱光強度を測定し、前記試薬混入前後の散乱光強度の計測値から、低濃度域の前記被検溶液中の前記特定成分の濃度を決定し、前記試薬混入前後の透過光強度の計測値から、高濃度域の前記被検溶液中の前記特定成分の濃度を決定することを特徴とする溶液濃度計測方法。  A method for measuring the concentration of a specific component in a test solution, the transmitted light intensity and scattered light intensity of the test solution before and after mixing a reagent that changes the optical properties of the test solution caused by the specific component From the measured value of the scattered light intensity before and after mixing the reagent, determine the concentration of the specific component in the test solution in a low concentration region, and from the measured value of the transmitted light intensity before and after mixing the reagent, A solution concentration measuring method, comprising determining a concentration of the specific component in the test solution in a concentration range. 前記試薬混入前後の透過光強度の計測値と前記試薬混入前後の散乱光強度の計測値とを照合することにより、前記被検溶液中の浮遊粒子による誤計測の有無を検知することを特徴とする請求項記載の溶液濃度計測方法。By comparing the measured value of transmitted light intensity before and after mixing of the reagent with the measured value of scattered light intensity before and after mixing of the reagent, it is possible to detect the presence or absence of erroneous measurement due to suspended particles in the test solution. The solution concentration measuring method according to claim 1 . 濃度が既知の基準溶液と前記被検溶液とについて、前記試薬混入前後の透過光強度および散乱光強度の少なくとも一方を同条件で計測し、前記基準溶液の計測値により、前記被検溶液の計測値を補正して前記被検溶液中の前記特定成分の濃度を求めることを特徴とする請求項または記載の溶液濃度計測方法。For the reference solution having a known concentration and the test solution, at least one of transmitted light intensity and scattered light intensity before and after mixing of the reagent is measured under the same conditions, and the test solution is measured based on the measured value of the reference solution. solution concentration measuring method according to claim 1 or 2, wherein the corrected values determine the concentration of the specific component in the test solution. 前記基準溶液が、前記特定成分を含まない水であることを特徴とする請求項記載の溶液濃度計測方法。4. The solution concentration measuring method according to claim 3 , wherein the reference solution is water not containing the specific component. 請求項1〜のいずれかに記載の溶液濃度計測方法によって前記被検溶液のタンパク質濃度を求め、前記試薬混入以前に前記被検溶液の旋光度を計測することによって前記被検溶液中の旋光性物質濃度を求め、ついで前記タンパク質濃度および前記旋光性物質濃度から、前記タンパク質以外の旋光性物質の濃度を求めることを特徴とする溶液濃度計測方法。Optical rotation in the test solution by obtaining a protein concentration of the test solution by the solution concentration measuring method according to any one of claims 1 to 4 and measuring an optical rotation of the test solution before mixing with the reagent. A solution concentration measuring method comprising: obtaining a concentration of an active substance, and then obtaining a concentration of an optical rotatory substance other than the protein from the protein concentration and the optical rotatory substance concentration. 被検溶液に光を照射する光源と、前記光が前記被検溶液を透過するように前記被検溶液を保持するサンプルセルと、前記被検溶液を透過した光を検知する光センサー1と、前記被検溶液中を前記光が伝搬する際に発生した散乱光を検知する光センサー2と、前記被検溶液に前記被検溶液中の特定成分のみの光学特性を変化させる試薬を混入する混入機と、前記混入機を制御し、前記光センサーの出力信号を解析するコンピューターとを備え、前記試薬混入前後の前記光センサー1の出力信号の計測値から、高濃度域の前記被検溶液中の特定成分の濃度を求め、前記試薬混入前後の前記光センサー2の出力信号の計測値から、低濃度域の前記被検溶液中の特定成分の濃度を求めることを特徴とする溶液濃度計測装置。  A light source for irradiating the test solution with light, a sample cell for holding the test solution so that the light passes through the test solution, a photosensor 1 for detecting light transmitted through the test solution, An optical sensor 2 that detects scattered light generated when the light propagates in the test solution, and a mixture that mixes a reagent that changes the optical characteristics of only a specific component in the test solution into the test solution And a computer for controlling the mixing device and analyzing the output signal of the photosensor, and from the measured value of the output signal of the photosensor 1 before and after mixing the reagent, in the test solution in the high concentration range The concentration of the specific component is determined, and the concentration of the specific component in the test solution in the low concentration range is determined from the measured value of the output signal of the photosensor 2 before and after mixing the reagent. . 前記試薬混入前後の前記光センサー1の出力信号の計測値と前記試薬混入前後の前記光センサー2の出力信号の計測値とを照合することにより、前記被検溶液中の浮遊粒子による誤計測の有無を検知することを特徴とする請求項記載の溶液濃度計測装置。By comparing the measured value of the output signal of the photosensor 1 before and after mixing of the reagent with the measured value of the output signal of the photosensor 2 before and after mixing of the reagent, erroneous measurement due to suspended particles in the test solution 7. The solution concentration measuring device according to claim 6, wherein presence or absence is detected. さらに、略平行光を投射する単色光源と、前記略平行光のうち特定方向の偏光成分のみを透過する偏光子と、前記被検溶液に磁場を印加する手段と、前記磁場を制御する磁場制御手段と、前記磁場を制御する際に前記磁場を振動変調する磁場変調手段と、前記被検溶液を透過した光のうち特定方向の偏光成分のみを透過する検光子と、前記検光子を透過した光を検知する光センサー3と、前記光センサー3の出力信号を前記磁場変調手段の振動変調信号を参照信号として位相敏感検波するロックインアンプと、前記磁場制御手段の磁場制御信号と前記ロックインアンプの出力信号にもとづいて前記被検溶液の旋光度を算出し、これを旋光性物質の濃度に換算する手段とを備え、前記サンプルセルは前記偏光子を透過した光が透過するように前記被検溶液を保持しており、
前記試薬混入前後に計測した被検溶液の透過光強度の計測値から、または前記光センサー3の出力信号を前記透過光の信号と見なして、前記光センサー3の出力信号の計測値から、前記被検溶液のタンパク質濃度を求め、前記算出された旋光度と前記タンパク質濃度から、前記被検溶液の前記タンパク質濃度と前記タンパク質以外の旋光性物質の濃度を確定することを特徴とする請求項または記載の溶液濃度計測装置
Furthermore, a monochromatic light source that projects substantially parallel light, a polarizer that transmits only a polarized light component in a specific direction of the substantially parallel light, means for applying a magnetic field to the test solution, and magnetic field control that controls the magnetic field Means, a magnetic field modulation means for vibrationally modulating the magnetic field when controlling the magnetic field, an analyzer that transmits only a polarized component in a specific direction out of the light transmitted through the test solution, and the analyzer that has passed through the analyzer An optical sensor 3 that detects light; a lock-in amplifier that detects a phase-sensitive detection of an output signal of the optical sensor 3 using a vibration modulation signal of the magnetic field modulation means as a reference signal; a magnetic field control signal of the magnetic field control means; Means for calculating the optical rotation of the test solution based on the output signal of the amplifier, and converting the optical rotation into the concentration of the optically-rotating substance, and the sample cell is arranged so that the light transmitted through the polarizer is transmitted. Holds the test solution,
From the measured value of the transmitted light intensity of the test solution measured before and after mixing of the reagent, or the output signal of the optical sensor 3 is regarded as the transmitted light signal, and from the measured value of the output signal of the optical sensor 3, claim, characterized in that determined the protein concentration of the test solution, from the protein concentration and the calculated optical rotation, to determine the concentration of the optical active substance of the protein concentration and other than said protein of said sample solution 6 Alternatively, the solution concentration measuring device according to 7 .
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