JP3549951B2 - Ultra-trace nitrogen component measurement device - Google Patents

Description

【００３１】
前記試料反応管１１の試料取出し口１３は、加熱配管１８を介して本実施例で脱塩、脱ハロゲンのために新たに付加される液体ハロゲンスクラバー１９の供給側に接続されている。
【００３２】
ここで、前記加熱配管１８は、試料反応管１１内での熱酸化分解によって発生する酸化窒素（ＮＯ）とハロゲンとを含む分解ガスＣ、及び水蒸気Ｄ等が、液体アルカリスクラバー１９に達する以前に管路内に吸着されないように加温する。また、前記液体アルカリスクラバー１９は、図３に示す如く、吸収瓶（内容積・約１００ｍｌ）２０の内部にハロゲン吸収溶液（０．１Ｎ−ＮａＨＣＯ_３ ）２１を所要量（５０ｍｌ程度）容納すると共に、前記加熱配管１８の排出端に設けたガラスフィルター２２を瓶内底部、つまりはハロゲン吸収溶液２１内に開口させ、且つ瓶内上部空間部から次に述べる管路２３を取出して構成され、前記加熱配管１８を通して給送される反応後の酸化窒素（ＮＯ）とハロゲンとを含む分解ガスＣ、及び水蒸気Ｄ等からの脱塩、脱ハロゲンを行なう。
【００３３】
前記液体アルカリスクラバー１９の排出側は、管路２３を介して電子除湿器２４の供給側に接続されている。
【００３４】
ここで、前記電子除湿器２４は、管路２３を通して給送される脱塩、脱ハロゲン後の分解ガスＣ、水蒸気Ｄ等のうちから水分を除湿し、該除湿された水分はドレンポット２４ａに排出される。
【００３５】
前記電子除湿器２４の排出側は、管路２５を介してガス混合器２６の供給側に接続されている。
【００３６】
ここで、前記ガス混合器２６は、管路２５を通して給送される脱水後の分解ガスＣを混合して均一化する。
【００３７】
前記ガス混合器２６の排出側は、管路２７を介して化学発光セル部２８に接続されており、且つ前記キャリアガス（Ｏ_２ ）もまたオゾナイザー２９を経た上で、生成されたオゾン（Ｏ_３ ）Ｅが同様に化学発光セル部２８に供給される。
【００３８】
ここで、前記化学発光セル部２８では、管路２７を通して給送される除湿後の分解ガスＣ、この場合、酸化窒素（ＮＯ）と、前記オゾナイザー２９を経たオゾン（Ｏ_３）とが次の式２のように気相反応されるが、該気相反応の過程において５９０〜２５００ｎｍの波長域の光を発して化学発光する。そして、この場合、図示省略したが、発生した光を光電子増倍管で受光後、その受光信号データ出力を増幅して指示計、つまり、ＮＯ（酸化窒素）計で示すと共に、該信号データＦをデータ処理器３０に出力して波形解析し、窒素分濃度に演算処理した上で、このようにして得た窒素成分の分析・測定結果をプリントアウトする。
【００３９】
【式２】

【００４０】
一方、前記化学発光セル部２８には、活性炭のカートリッジからなるオゾンスクラバー３１を介して真空ポンプ３２が接続されており、オゾンスクラバー３１おいては、化学発光で消費されなかった過剰のＯ_３ をＣＯ_２ に分解し、また、真空ポンプ３２では、化学発光セル部２８を減圧すると共に、分解されたＣＯ_２ を外部に排出するのである。
【００４１】
続いて、本実施例による窒素成分測定装置を用いた実験例について述べる。
【００４２】
【実験例】
本窒素成分測定装置を用いた実験例において使用する試薬の種類、及び分析・測定条件は、次の通りである。
【００４３】
試薬
（ａ）０．１Ｍ−ＮａＨＣＯ_３
和光純薬 容量分析用０．１Ｍ−ＮａＨＣＯ_３ ，８．４ｇを純水に溶解し、１０００ｃｃに増量して使用
（ｂ）純水
ヤマト科学 オートスチル ＷＡ−５２
（ｃ）窒素標準液
和光純薬 試薬特級硫酸アンモニウム（（ＮＨ_４ ）_２ ＳＯ_４ ，ＭＷ＝１３２．１４）
Ｎ−１０００ｐｐｍ原液−（ＮＨ_４ ）_２ ＳＯ_４ ，４．７２ｇを純水に溶解し、１０００ｃｃに増量して使用
低濃度窒素標準液は、Ｎ−１０００ｐｐｍ原液を希釈して使用
【００４４】
測定条件
（ａ）窒素成分測定装置
ＩＮＬＥＴ ：６５０℃
ＣＡＴＡＬＹＳＴ：８００℃
Ｏ_２ ：５００ｍｌ／ｍｉｎ
ＮＯ計 ：２ｐｐｍ ＲＡＮＧＥ
ＲＥＣＯＲＤＥＲ：５００ｍＶ／Ｓ ＲＡＮＧＥ
（ｂ）自動ビュレット装置
ＩＮＪ．Ｓ． ：２０μｌ／ｓｅｃ
ＩＮＪ．Ｖ． ：２００μｌ，４００μｌ，１０００μｌ，５０００μｌ
【００４５】
先にも述べた如く、定量下限０．１ｐｐｍを目標としたときに、試料注入量としては、２００μｌ〜１０００μｌを考慮する必要があるが、多量の試料を注入した場合には、そのクエンチングが問題になる。これは、多量の試料を注入したときに発生する水蒸気が、従来の窒素分析装置に組み込まれた電子除湿器では完全に回収されずに、その水分が化学発光セル部に対して導入され、減光作用を生ずることによるものである。
【００４６】
先ず最初に、既存の電子除湿器の能力を再確認するために、Ｈ_２ Ｏを５００μｌ注入したところ、該電子除湿器のアウト側から水蒸気が排出されることが確認された。
【００４７】
そこで、除湿能力を強化するために、先に述べた如くに液体アルカリスクラバーを設置することにより、前記と同様に、Ｈ_２ Ｏを５００μｌ注入しても、電子除湿器のアウト側からの水蒸気の排出がないことを確認できた。
【００４８】
従って、ここでの多量試料注入法には、電子除湿器の前流側に液体アルカリスクラバーを設置するのである。
【００４９】
このようにしてなされた試料（硫安標準液）注入量が夫々に２００μｌ，４００μｌ，１０００μｌ，５０００μｌの各場合の注入結果は、次の表１及び図４のグラフ、表２及び図５のグラフ、表３及び図６のグラフ、表４及び図７のグラフの通りであり、また、そのときの注入検量線は、図８のグラフの通りである。
【００５０】
これらの実験結果から、本実施例装置が、塩分を含有する被測定試料中の超微量窒素成分の測定に極めて有効であることが分かる。
【００５１】
【表１】

【００５２】
【表２】

【００５３】
【表３】

【００５４】
【表４】

【００５５】
【発明の効果】
以上、実施の態様によって詳述したように、本発明の超微量窒素成分の測定装置によれば、キャリアガス（Ｏ_２ ）を合わせて注入される塩分を含有した多量の被測定試料を加熱反応手段によって酸化反応させ、且つまた、該加熱反応後の酸化窒素、ハロゲンを含む分解ガス中から脱塩、脱ハロゲン手段によって塩分とハロゲンとを除去した上で、該脱塩、脱ハロゲン処理された分解ガスを除湿手段によって除湿させ、さらに、該除湿処理された分解ガスにオゾン（Ｏ_３ ）を合わせて化学発光手段によって化学発光させると共に、該発光信号データをデータ処理手段で演算処理するようにしたので、従来装置に比較するとき、除湿手段の前流側に脱塩、脱ハロゲン手段を介在させるだけの極めて簡単な構成であるにも拘らず、ここで求めようとする塩分を含有した被測定試料中の窒素分濃度を正確且つ容易に測定できるという実用上有益な特長を有するものである。
【図面の簡単な説明】
【図１】本発明の一実施例を適用した窒素成分測定装置の概要構成を示すブロック図である。
【図２】同上実施例装置における試料滴定部としての自動ビュレット装置の詳細構成を模式的に示す説明図である。
【図３】同上実施例装置に組み込まれる液体アルカリスクラバーの詳細構成を模式的に示す説明図である。
【図４】同上実施例装置に対して試料（硫安標準液）を２００μｌ注入したときの結果を示すグラフである。
【図５】同上実施例装置に対して試料（硫安標準液）を４００μｌ注入したときの結果を示すグラフである。
【図６】同上実施例装置に対して試料（硫安標準液）を１０００μｌ注入したときの結果を示すグラフである。
【図７】同上実施例装置に対して試料（硫安標準液）を５０００μｌ注入したときの結果を示すグラフである。
【図８】従来の窒素成分測定装置の概要構成を示すブロック図である。
【符号の説明】
１１ 試料反応管
１２ 試料反応管の試料注入口
１３ 試料反応管の試料取出し口
１４ 試料反応炉
１５ 加熱コイル
１６ 自動ビュレット装置
１６ａ ＬＣ用ニードル
１７ ガス流量計
１８ 加熱配管
１９ 液体ハロゲンスクラバー
２０ 吸収瓶
２１ ハロゲン吸収溶液
２２ ガラスフィルター
２３ 管路
２４ 電子除湿器
２４ａ 電子除湿器のドレンポット
２５ 管路
２６ ガス混合器
２７ 管路
２８ 化学発光セル部
２９ オゾナイザー
３０ データ処理器
３１ オゾンスクラバー
３２ 真空ポンプ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for measuring an ultra-trace amount of nitrogen, and more particularly, to an apparatus for measuring the amount of nitrogen in an aqueous sample applied to water quality control or the like. The present invention relates to an apparatus for measuring an ultra-trace amount of a nitrogen component, which can be accurately and easily analyzed and measured.
[0002]
[Prior art]
In general, this type of aqueous component nitrogen component measuring device is widely known as a means for analyzing and measuring the total nitrogen component amount in various types of aqueous samples to be analyzed with high sensitivity based on a catalytic oxidation / chemiluminescence method as an analysis principle. It is effectively used for water quality control and the like, for example, for controlling nitrogen components in environmental water (river water, groundwater, seawater, industrial wastewater) and pure water (for semiconductor production and nuclear power generation).
[0003]
FIG. 8 shows a schematic configuration of a conventional nitrogen component measuring device that has been used conventionally.
[0004]
That is, in the configuration of the conventional nitrogen component measuring apparatus shown in FIG. 8, reference numeral 41 denotes a sample reaction tube in which a sample inlet 42 is formed on the upper side, and a sample outlet 43 is formed on the lower side. This is a sample reaction furnace that constitutes an electric furnace by surrounding a required heating coil 45 around the outer periphery of a tube 41.
[0005]
Here, the sample reaction tube 41 is formed of a quartz tube filled with an oxidation catalyst (a platinum-supported catalyst), and a carrier gas (eg, a gas through a gas flow meter 46 from outside) is provided in the sample reaction tube 41. O ₂ ) The sample A to be measured is injected (10 μl to 5000 μl) from the sample injection port 42 by using a sample injection device (not shown) at the same time as the introduction of O ₂ ) B. The sample A to be measured, which is injected into the sample reaction tube 41, is heated (heating range: 0 to 1000 ° C.) in accordance with the introduction of, and thermal decomposition is performed.
[0006]
The sample outlet 43 of the sample reaction tube 41 is connected to a supply side of an electronic dehumidifier 48 via a heating pipe 47.
[0007]
Here, the heating pipe 47 is connected to a pipe before the decomposition gas C containing nitrogen oxide (NO) and halogen generated by thermal decomposition in the sample reaction tube 41 and the steam D reach the electronic dehumidifier 48. The electronic dehumidifier 48 removes moisture from the reaction-decomposed gas C, water vapor D, and the like, which is fed through the heating pipe 47, so that the water is not adsorbed in the passage. The drained water is discharged to the drain pot 48a.
[0008]
The discharge side of the electronic dehumidifier 48 is connected to the supply side of a gas mixer 50 via a pipe 49.
[0009]
Here, the gas mixer 50 mixes and homogenizes the decomposed gas C from which water has been removed by the electronic dehumidifier 48.
[0010]
The discharge side of the gas mixer 50 is connected to a chemiluminescence cell section 52 via a pipe line 51, and the carrier gas (O ₂ ) also passes through an ozonizer 53, and then the ozone (O ₂ ) ₃ ) is similarly supplied to the chemiluminescent cell section 52, where the nitric oxide (NO) supplied from the gas mixer 50 side reacts with ozone (O ₃ ) passed through the ozonizer 53. And emits chemiluminescence.
[0011]
On the other hand, a vacuum pump 55 is connected to the chemiluminescent cell section 52 via an ozone scrubber 54 composed of an activated carbon cartridge. In the ozone scrubber 54, excess O ₃ not consumed by chemiluminescence is removed. It is decomposed into CO ₂ , and the vacuum pump 55 reduces the pressure of the chemiluminescent cell unit 53. The electrical signal obtained by the reaction between NO and O _{3 in the} chemiluminescent cell section 52 is subjected to waveform analysis by a data processor 56 to calculate the nitrogen concentration, and the analysis of the nitrogen component thus obtained is performed.・ The measurement result is printed out.
[0012]
[Problems to be solved by the invention]
By the way, in the analysis and measurement concentration of the total amount of nitrogen components in an aqueous sample using a nitrogen component measurement device of this type, generally, high-precision measurement to 0.1 ppm or less is required. Under measurement conditions, its analysis and measurement are extremely difficult.
[0013]
In addition, among the water-based samples to be measured, particularly, in the case of a large amount of salt such as seawater or some factory wastewater, the large amount of salt is contained in the sample by injecting the large amount of salt into the reaction section. There is a case where some salt is deposited in a system from the reaction part to the detection part, particularly in a heating pipe, and blocks the pipe. On the other hand, depending on the halogen gas generated when the large salt sample is injected into the reaction section, heated, and subjected to the oxidation reaction, corrosion may occur in the chemiluminescent cell section, the vacuum pump, and the like incorporated in the system. is there.
[0014]
Looking at each of these points with this type of nitrogen component measuring device from the measurement results, in the short term, the daily fluctuation of the total nitrogen component measurement value is caused, while in the long term, NO (nitrogen oxide) There is a disadvantage that the sensitivity of the meter is lowered and troubles occur in the chemiluminescent cell portion, the vacuum pump, and the like.
[0015]
As a countermeasure, conventional nitrogen analyzers are generally used to prevent clogging of a heating pipe or the like due to salt contained in an aqueous sample to be measured and to prevent corrosion of a chemiluminescent cell portion, a vacuum pump, and the like. Used a solid halogen scrubber.However, such a solid halogen scrubber has a short service life due to the fact that the salt content finishes coating the scrubber surface, and furthermore, the solid halogen scrubber has a comparative dehalogenation effect. However, it was not always effective due to its low quality.
[0016]
The present invention has been made in order to solve such a conventional problem, and an object thereof is to desalinate and dehalogenate in an apparatus an ultra-trace nitrogen component which can be easily formed. It is to provide a measuring device.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, a measuring apparatus according to the present invention is an apparatus for measuring an ultra-trace amount of nitrogen component by injecting a large amount of a sample containing a salt to be measured from a sample injecting means. A heating reaction means for injecting a large amount of the sample to be contained in accordance with the introduction of the carrier gas (O ₂ ), and thermally decomposing and oxidizing, and containing nitrogen oxide and halogen after the heating reaction by the heating reaction means A liquid alkaline scrubber for removing salt and halogen from the decomposed gas, a dehumidifying means for dehumidifying the decomposed gas subjected to desalination and dehalogenation by the liquid alkaline scrubber, and a decomposed gas dehumidified by the dehumidifying means Means for causing a gaseous reaction of ozone (O ₃ ) with ozone (O ₃ ) to perform chemiluminescence, and calculating and outputting a nitrogen concentration from emission signal data by the chemiluminescence means And a data processing means. Further, the measuring device according to the present invention is characterized in that the sample injection means is an automatic burette device.
[0018]
Therefore, in the measuring device for ultra-trace nitrogen components of the present invention, a large amount of the sample to be injected is oxidized by the heating reaction means and desalted from the decomposition gas containing nitrogen oxide and halogen after the heating reaction. After the salt and halogen are removed by the dehalogenating means, the decomposed gas subjected to the desalting and dehalogenating treatment is dehumidified by the dehumidifying means, and the decomposed gas subjected to the dehumidifying treatment is subjected to chemiluminescence by the chemiluminescent means. At the same time, the emission signal data is subjected to arithmetic processing by the data processing means, and the required nitrogen concentration is measured.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the measuring device for ultra-trace nitrogen components according to the present invention will be described in detail.
[0020]
The present inventors have sought to address the current situation of the solid halogen scrubber incorporated in the conventional nitrogen component measuring apparatus described above, that is, the problems such as a short service life of the solid halogen scrubber and a low dehalogenation effect. In view of the above, as a result of intensive development efforts to improve each of these problems, the present invention was devised as described below.
[0021]
First, the present inventors studied an apparatus for measuring an ultra-trace amount of nitrogen component by a large-volume sample injection method.
[0022]
First, the sample injection method when the lower limit of quantification was set to 0.1 ppm and the injection amount were examined.
[0023]
That is, in the sample injection method here, an automatic buret device (automatic titrator; 10 ml volume cassette) is used in view of injecting a large amount of sample and injecting the sample at a constant speed. The syringe used was a straight-cut syringe for LC (manufactured by Leodyne). The sample injection amount was determined to be sufficient to allow injection of up to 10 ml by using an automatic burette device for the sample injection.
[0024]
Subsequently, quenching measures when a large amount of sample was injected were examined.
[0025]
In the conventional apparatus, when a sample is injected in an amount of 500 μl or more, water vapor comes out from the out side of the electronic dehumidifier. Therefore, a liquid alkaline scrubber is arranged on the upstream side of the electronic dehumidifier to improve the dehumidifying performance. It was confirmed that sufficient dehumidification could be achieved with these liquid alkaline scrubbers and the electronic dehumidifier even when the amount of was increased to about 5 ml.
[0026]
【Example】
FIGS. 1 to 3 show the overall outline of the device configuration according to one embodiment of the present invention set as described above.
[0027]
FIG. 1 is a block diagram showing an outline of an apparatus for measuring an ultra-trace nitrogen component to which an embodiment of the present invention is applied, and FIG. 2 is a schematic view showing a detailed configuration of an automatic burette apparatus as a sample titration unit in the measuring apparatus. FIG. 3 is an explanatory view schematically showing a detailed configuration of a liquid alkaline scrubber incorporated in the measuring device.
[0028]
In the configuration of the nitrogen component measuring apparatus of the embodiment shown in FIGS. 1 to 3, reference numeral 11 denotes a sample reaction tube having a sample inlet 12 formed on the upper side and a sample outlet 13 formed on the lower side, respectively. This is a sample reaction furnace which constitutes an electric furnace by surrounding a required heating coil 15 around the outer periphery of the sample reaction tube 11. Further, reference numeral 16 denotes an automatic burette device newly added in the present embodiment capable of injecting a large amount of sample. As shown in FIG. 2, the automatic burette device 16 inserts an LC needle 16a into the sample injection port 12. Used.
[0029]
Here, the sample reaction tube 11 is a quartz tube filled with an oxidation catalyst (platinum-supported catalyst) inside. In accordance with the introduction of O ₂ ) B, the required sample A is injected from the sample injection port 12 by the automatic buret device 16 by a required amount (injection amount range: 10 μl to 5000 μl). In the sample reaction furnace 14, the sample A to be measured injected into the sample reaction tube 11 is heated (heating range: 0 to 1000 ° C.) in accordance with the introduction of the carrier gas B, and oxidized according to the following equation 1. Decompose.
[0030]
(Equation 1)

[0031]
The sample outlet 13 of the sample reaction tube 11 is connected via a heating pipe 18 to the supply side of a liquid halogen scrubber 19 which is newly added for desalting and dehalogenation in this embodiment.
[0032]
In this case, the heating pipe 18 is used for the decomposition gas C containing nitrogen oxide (NO) and halogen generated by the thermal oxidative decomposition in the sample reaction tube 11 and the steam D before reaching the liquid alkaline scrubber 19. Heat so that it is not adsorbed in the pipeline. Further, as shown in FIG. 3, the liquid alkaline scrubber 19 stores a required amount (about 50 ml) of a halogen absorbing solution (0.1 N-NaHCO ₃ ) 21 in an absorption bottle (inner volume, about 100 ml) 20. A glass filter 22 provided at the discharge end of the heating pipe 18 is opened into the bottom of the bottle, that is, into the halogen-absorbing solution 21, and a pipe 23 described below is taken out from the upper space in the bottle. Desalination and dehalogenation are performed from the decomposition gas C containing the reacted nitrogen oxide (NO) and halogen, which is fed through the heating pipe 18, and the steam D and the like.
[0033]
The discharge side of the liquid alkaline scrubber 19 is connected to the supply side of an electronic dehumidifier 24 via a pipe 23.
[0034]
Here, the electronic dehumidifier 24 dehumidifies water from the degassed gas C, steam D and the like after desalination and dehalogenation fed through the pipeline 23, and the dehumidified water is supplied to the drain pot 24a. Is discharged.
[0035]
The discharge side of the electronic dehumidifier 24 is connected to the supply side of a gas mixer 26 via a pipe 25.
[0036]
Here, the gas mixer 26 mixes and homogenizes the decomposed gas C supplied through the pipe 25 after dehydration.
[0037]
The discharge side of the gas mixer 26 is connected to a chemiluminescence cell section 28 via a pipe line 27, and the carrier gas (O ₂ ) also passes through an ozonizer 29, and the generated ozone (O ₂ ) ₃ ) E is similarly supplied to the chemiluminescent cell section 28.
[0038]
Here, in the chemiluminescent cell section 28, the decomposed gas C after dehumidification fed through the pipe line 27, in this case, nitric oxide (NO), and ozone (O ₃ ) passed through the ozonizer 29 are as follows. The gas phase reaction is performed as shown in Formula 2, and in the course of the gas phase reaction, light is emitted in a wavelength range of 590 to 2500 nm to perform chemiluminescence. In this case, although not shown, after the generated light is received by the photomultiplier tube, the output of the received light signal data is amplified and indicated by an indicator, that is, a NO (nitrogen oxide) meter, and the signal data F Is output to the data processor 30 to analyze the waveform and calculate the nitrogen concentration, and then print out the analysis and measurement results of the nitrogen component thus obtained.
[0039]
[Equation 2]

[0040]
On the other hand, a vacuum pump 32 is connected to the chemiluminescent cell section 28 via an ozone scrubber 31 composed of an activated carbon cartridge. In the ozone scrubber 31, excess O ₃ not consumed by chemiluminescence is removed. It decomposes into CO ₂ , and the vacuum pump 32 decompresses the chemiluminescent cell unit 28 and discharges the decomposed CO ₂ to the outside.
[0041]
Subsequently, an experimental example using the nitrogen component measuring device according to the present embodiment will be described.
[0042]
[Experimental example]
The types of reagents used in the experimental examples using the present nitrogen component measuring device and the analysis / measurement conditions are as follows.
[0043]
Reagent (a) 0.1 M NaHCO ₃
Wako Pure Chemicals 0.1 M-NaHCO ₃ for volumetric analysis, 8.4 g, was dissolved in pure water, and the volume was increased to 1000 cc. (B) Pure water Yamato Kagaku Auto Still WA-52
(C) Nitrogen standard solution Wako Pure Chemicals reagent grade ammonium sulfate ((NH ₄ ) ₂ SO ₄ , MW = 132.14)
N-1000 ppm stock solution- (NH ₄ ) ₂ SO ₄ , 4.72 g were dissolved in pure water and the volume was increased to 1000 cc. The low concentration nitrogen standard solution was used by diluting the N-1000 ppm stock solution.
Measurement conditions (a) Nitrogen component measuring device INLET: 650 ° C
CATALYST: 800 ° C
O ₂ : 500 ml / min
NO total: 2 ppm RANGE
RECORDER: 500mV / S RANGE
(B) Automatic bullet device INJ. S. : 20 μl / sec
INJ. V. : 200 μl, 400 μl, 1000 μl, 5000 μl
[0045]
As described above, when the lower limit of quantification is targeted at 0.1 ppm, it is necessary to consider a sample injection volume of 200 μl to 1000 μl. However, when a large amount of sample is injected, the quenching is It becomes a problem. This is because the water vapor generated when a large amount of sample is injected is not completely recovered by the electronic dehumidifier incorporated in the conventional nitrogen analyzer, but the water is introduced into the chemiluminescence cell unit, and the water is reduced. This is due to the effect of light.
[0046]
First, 500 μl of H ₂ O was injected to reconfirm the performance of the existing electronic dehumidifier, and it was confirmed that water vapor was discharged from the out side of the electronic dehumidifier.
[0047]
Therefore, in order to enhance the dehumidifying ability, by installing the liquid alkaline scrubber as described above, even if 500 μl of H ₂ O is injected as described above, even if 500 μl of H ₂ O is injected, water vapor from the out side of the electronic dehumidifier is removed. No emission was confirmed.
[0048]
Therefore, in this large-volume sample injection method, a liquid alkaline scrubber is installed upstream of the electronic dehumidifier.
[0049]
The injection results for each of the sample (ammonium sulfate standard) injection amounts of 200 μl, 400 μl, 1000 μl, and 5000 μl thus obtained are shown in the following graphs in Tables 1 and 4, and graphs in Tables 2 and 5, The results are as shown in the graphs of Tables 3 and 6, and the graphs of Tables 4 and 7, and the injection calibration curve at that time is as shown in the graph of FIG.
[0050]
From these experimental results, it can be seen that the apparatus of this example is extremely effective in measuring an ultra-trace nitrogen component in a sample to be measured containing salt.
[0051]
[Table 1]

[0052]
[Table 2]

[0053]
[Table 3]

[0054]
[Table 4]

[0055]
【The invention's effect】
As described above in detail in the embodiment, according to the measuring apparatus of the ultra-trace nitrogen component of the present invention, a large amount of the sample to be measured containing the salt injected together with the carrier gas (O ₂ ) is heated and reacted. After the heat reaction, the salt and the halogen were removed from the decomposed gas containing nitrogen oxide and halogen after the heating reaction, and then subjected to the desalting and dehalogenating treatment. The decomposed gas is dehumidified by the dehumidifying means, and further, ozone (O ₃ ) is combined with the dehumidified decomposed gas to cause chemiluminescence by the chemiluminescence means, and the luminescence signal data is arithmetically processed by the data processing means. Therefore, when compared with the conventional apparatus, despite having a very simple configuration in which the desalting and dehalogenating means is interposed on the upstream side of the dehumidifying means, it is determined here. It has a practically useful feature that the concentration of nitrogen in a sample to be measured containing a salt can be accurately and easily measured.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a nitrogen component measuring device to which an embodiment of the present invention is applied.
FIG. 2 is an explanatory view schematically showing a detailed configuration of an automatic buret apparatus as a sample titration unit in the apparatus of the embodiment.
FIG. 3 is an explanatory view schematically showing a detailed configuration of a liquid alkaline scrubber incorporated in the apparatus of the embodiment.
FIG. 4 is a graph showing the result when 200 μl of a sample (ammonium sulfate standard solution) was injected into the apparatus of the embodiment.
FIG. 5 is a graph showing the results when 400 μl of a sample (ammonium sulfate standard solution) was injected into the apparatus of the example.
FIG. 6 is a graph showing the result when 1000 μl of a sample (ammonium sulfate standard solution) was injected into the apparatus of the above Example.
FIG. 7 is a graph showing the results when 5000 μl of a sample (ammonium sulfate standard solution) was injected into the apparatus of the above Example.
FIG. 8 is a block diagram showing a schematic configuration of a conventional nitrogen component measuring device.
[Explanation of symbols]
Reference Signs List 11 Sample reaction tube 12 Sample reaction tube sample inlet 13 Sample reaction tube sample outlet 14 Sample reaction furnace 15 Heating coil 16 Automatic burette device 16a LC needle 17 Gas flow meter 18 Heating pipe 19 Liquid halogen scrubber 20 Absorption bottle 21 Halogen absorbing solution 22 Glass filter 23 Pipe 24 Electronic dehumidifier 24a Drain pot 25 for electronic dehumidifier Pipe 26 Gas mixer 27 Pipe 28 Chemiluminescent cell section 29 Ozonizer 30 Data processor 31 Ozone scrubber 32 Vacuum pump

Claims (2)

An apparatus for measuring a trace amount of nitrogen component by injecting a large amount of a sample containing a salt to be measured from a sample injection means,
Heating reaction means for injecting a large amount of the sample containing the salt in accordance with the introduction of the carrier gas (O ₂ ), and thermally decomposing and oxidizing; nitric oxide after the heat reaction by the heating reaction means; A liquid alkali scrubber for removing salt and halogen from the decomposition gas containing halogen, a dehumidifying means for dehumidifying the decomposed gas which has been desalinated and dehalogenated by the liquid alkaline scrubber; At least a chemiluminescence unit for causing a gas phase reaction of the decomposed gas with ozone (O ₃ ) to cause chemiluminescence, and a data processing unit for calculating and outputting a nitrogen concentration from emission signal data of the chemiluminescence unit. An ultra-trace nitrogen component measuring device, characterized in that: The apparatus according to claim 1, wherein the sample injection unit is an automatic burette device.

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