JP2002243715A - Amino acid analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an amino acid analyzer capable of carrying out separation at high speed. SOLUTION: This analyzer is composed of a separation column 10, a buffer solution pump 7 for feeding plural buffer solutions 1, 2, 3, 4 to the separation column 10, a sampler 7 provided in a flow passage between the pump 7 and the column 10 to introduce an analyzed sample into the flow passage, and a reaction coil 14 for reacting an amino acid separated by the separation column 10 with a ninhydrin reagent after they are mixed. A ratio Ll/R of a length Ll to an inside diameter R of the separation column 10 is 10 or less, and a particle size of an ion exchange resin filled into the column 10 is 4 μm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amino acid analyzer, and more particularly to an amino acid analyzer suitable for high-speed amino acid analysis by liquid chromatography.

[0002]

2. Description of the Related Art The amino acid analysis method is roughly classified into a standard analysis method (hereinafter referred to as a "standard method") for analyzing amino acids of about 18 amino acids of a protein hydrolyzate, and an amino acid analysis of amino acids analogous to a biological fluid. It can be classified into the target biological fluid method (hereinafter referred to as “biological fluid method”). Among the conventional amino acid analysis methods and apparatuses, the standard method is described in, for example, JP-A-64-44848, JP-B-3-10076 and JP-B-4-64584. The biological fluid method is described in Japanese Patent Publication No. 2-59428 and Japanese Patent Publication No. 4-194750.

[0003] Amino acid analysis requires a long analysis time due to the large number of analysis components. Conventionally, the standard method required 30 minutes, and the biological fluid method required 110 to 140 minutes.

[0004]

As described above, in the amino acid analyzer which requires 30 minutes by the standard method, the conditions of the analyzer include, for example, Japanese Patent Laid-Open No. 1-227959.
As described in the publication, the particle size of the ion exchange resin is 3 μm, and the inner diameter of the separation column filled with the ion exchange resin is 4.6 mm. Although not explicitly described in this publication, the length of this column is 60 mm. When the amino acids are analyzed by the standard method in 30 minutes, the flow rate of the buffer solution is 0.46 ml / min, and the load pressure at that time is about 110 kgf / cm ² .

In general, the analysis time is almost inversely proportional to the buffer flow rate. Therefore, the buffer flow rate was set to 0.55 ml / min.
Theoretically, the analysis time can be reduced to 25 minutes, but the load pressure at this time is about 130 kgf / cm
It becomes ² . The critical load pressure of the separation column differs depending on the device, and the pressure value to be recognized as the critical load pressure differs depending on the analyst, and a column exceeding the critical load pressure needs to be refilled. . Here, assuming that the critical load pressure is 150 kgf / cm ² , as described above, if the buffer solution flow rate is set so that the analysis time is 25 minutes, the initial analysis is possible. As the number of analyzes increases, the load pressure on the column increases, and the life of the column is shorter than in the case of 30-minute analysis.

Therefore, although the above-mentioned separation column can perform analysis for 25 minutes, there is a problem that the life of the separation column is short and not practical. In addition, there is a problem that analysis faster than 25-minute analysis is impossible in relation to the critical load pressure.

The same can be said for the biological fluid method. Since the biological fluid method differs from the standard method in the components of the buffer solution and the column temperature at the start, the relationship between the flow rate and the pressure does not become the same as the standard method, and increases by about 20%.

Here, if the particle size of the ion exchange resin is increased, the pressure loss can be reduced. However, this means that the separation of each amino acid component by the ion exchange resin is poor.

Therefore, the conventional apparatus has a problem that it is difficult to perform analysis faster without impairing the separation.

[0010] Even if high separation is possible at the outlet of the separation column, the once separated ones are fused due to the effect of spreading in places other than the separation column,
At the time of detection by a photometer as a detector, a predetermined separation rate may not be obtained. That is, there is a problem that the separation is hindered by the influence of the spread outside the column.

An object of the present invention is to provide a higher-speed and higher-separation amino acid analyzer.

[0012]

In order to achieve the above object, the present invention provides a separation column, a liquid sending means for sending a plurality of buffers to the separation column, the liquid sending means and the separation column. A sampler that is provided in the flow path between the sampler and introduces the analysis sample into the flow path, a mixer that mixes the analysis sample separated by the separation column with a ninhydrin reagent, and a reaction coil that reacts the solution mixed by the mixer. Wherein the ratio (L1 / R) of the length L1 to the inner diameter R of the separation column is 10 or less, and the inner diameter R is 5 mm to 7 mm, and the separation column is packed. The ion exchange resin has a particle size of 4 μm or less.

In the above-mentioned amino acid analyzer, the flow rate of the buffer is preferably 1.0 ml / min or less.

In the above amino acid analyzer, preferably, the inner diameter r of the reaction coil is 0.25 mm or less, and the flow rate of the liquid flowing through the reaction coil is 1.0 ml.
/ Min or more.

[0015]

According to the present invention, the separation column has a ratio (L1 / R) of its length L1 to its inner diameter R of 10 or less and an inner diameter R of 5 mm to 7 mm. By setting the particle size of the exchange resin to 4 μm or less, the flow rate of the buffer solution can be increased without increasing the internal pressure of the separation column, so that high-speed analysis can be performed.

The flow rate of the buffer is 1.0 ml / mi.
By setting n or less, it is possible to suppress the spread of the separated components in the reaction coil and to perform analysis without lowering the separation rate.

Further, the inner diameter r of the reaction coil is
0.25 mm or less, and by setting the flow rate of the liquid flowing through the reaction coil to 1.0 ml / min or more,
Among the effects of the expansion in the reaction coil, the element due to the inner diameter is suppressed within a practical range, and the analysis without lowering the separation rate has been enabled.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing one embodiment of the present invention, the gist of the present invention will be described below.

As described above, the analysis time is considered to be almost inversely proportional to the buffer flow rate. Therefore, when the flow rate of the buffer solution is increased for the purpose of shortening the analysis time, the column load pressure rises abnormally, and the relationship between the buffer solution flow rate and the column load pressure deviates from a straight line above, and the relationship shown in FIG. Has been confirmed by experiments.

Here, FIG. 1A shows the flow rates of the buffer solution at 0.2 ml / min and 0.2 ml / min, respectively, using a conventionally used separation column having an inner diameter of 4.6 mm and a length of 60 mm.
3ml / min, 0.4ml / min, 0.5ml / m
in, 0.6 ml / min, 0.7 ml / min, 0.
FIG. 5 illustrates a relationship between a flow rate and a column pressure (kgf / cm ² ) when the flow rate is changed to 8 ml / min. Figure 1
As shown in (A), the buffer flow rate was 0.6 ml / min.
Until then, the relationship between the buffer flow rate and the column pressure is linear. However, the buffer flow rate was 0.6 ml / min.
, It was found out of the linear relationship. When the buffer flow rate was increased to 0.7 ml / min, the column load pressure was 172 kgf / cm ² . That is, this means that a long column life cannot be maintained due to the pressure increase.

FIG. 1B shows the relationship between the buffer solution flow rate and the column pressure by changing only the length without changing the inner diameter of the column. In FIG. 1B, the flow rate of the buffer solution and the column pressure were examined using a separation column having an inner diameter of 4.6 mm and a length of 40 mm.

As shown in FIG. 1B, even in a separation column having a length of 40 mm, the buffer solution flow rate is 0.6 ml / mi.
When n was exceeded, it was found that the relationship deviated from the linear relationship. When the buffer flow rate is 0.6 ml / min, the column pressure is 8
8 kgf / cm ² and a buffer flow rate of 0.7 ml / m
The column load pressure at the time of “in” was 112 kgf / cm ² , which indicates that the use limit was reached even though the column pressure was lower than that of the column having a length of 60 mm. The inventors thought that the limitation of the use of the column was not the column load pressure but the linear velocity of the buffer flowing through the column. By the way, the column inner diameter is 4.6m
buffer flow rate through the separation column is 0.6 ml / mi
The column linear velocity at the time of n is 36 mm / min.

This phenomenon occurs when a fine ion exchange resin having a particle size of 4 μm or less is used, and is considered to be a characteristic of a fine ion exchange resin having a particle size of 4 μm or less. .

Therefore, based on the above-described findings, the present inventors have studied the column size and increased the inner diameter of the column in order to increase the flow rate of the buffer solution while keeping this column linear velocity limit. . It is thought that by increasing the inner diameter of the separation column, the flow rate of the buffer solution can be increased, and theoretically, the analysis time can be reduced. At the same time, the column efficiency was improved by using a fine resin having a particle size of 4 μm or less, and the length of the separation column was shortened to prevent the possible pressure loss of the separation column from increasing when the buffer flow rate was increased. I am trying to do it. Then, the ratio of the inner diameter R of the separation column to the length L1 (L1
/ R), the ratio was determined to be 10 or less.

Further, even if high-speed analysis is enabled by using the above-mentioned separation column and the separation rate at the separation column outlet is increased, the spread outside the column by the flow path system downstream of the separation column can be separated. The effect on

Experiments have confirmed that the contribution of the reaction coil is about 80% in the flow path components that affect the expansion outside the column. Considering the effect of the spread in the reaction coil, the spread σ ² of the sample zone in the reaction coil can be expressed by the following (Equation 1).

Σ ² = πr ⁴ fL ² / 24Dm (Equation 1) where r is the radius of the reaction coil (mm), f is the column flow rate (m ³ / s), and L 2 is the length of the reaction coil ( m) and Dm are the diffusion constant of the solute in the buffer solution, and are based on laminar flow.

The unit of the spread σ is volume (m ³ ), and time (s) is generally a horizontal axis on a chromatogram. Therefore, the spread in units of time is defined as σ ^* (s).

Σ ^{* 2} = πr ⁴ L 1 / 24fDm (Equation 2) Here, when examining the spread σ ^{* in} units of time, the chromatogram has a shape as shown in FIG. In FIG. 2, the horizontal axis represents time (min). In such a chromatogram, the standard deviation σ ₁ of the peak is usually about 10 s. Therefore, the square (σ ₁ ) ² of the standard deviation σ ₁ of the peak is 100, and
If the spread can be suppressed within 20%, the spread becomes negligible for separation.

Therefore, when the spread σ ^* that satisfies Equation 3 is obtained, if the spread σ ^{* is set} to 4 s or less, it can be considered that the spread σ ^* can be ignored in terms of separation. (Σ ^* ) ² <0.2 × 100 (Equation 3) The time unit on the horizontal axis of the chromatogram is minute (mi).
Since n) is used, the spread σ ^* may be set to 0.067 min or less.

As can be seen from the above (Equation 2), the spread σ ^{* in} units of time is a function of the inner diameter r of the reaction coil, the length L2 of the reaction coil, and the column flow rate. Therefore,
In order to set the spread σ ^* to 0.067 min or less,
Looking calculated for ^(r 4 · L2) / f condition, diffusion constant Dm, since it has been experimentally determined a ^{1.20 × 10 -9 (m 2 /} s), (r 4 L2) / f <1.5 × 10 ⁻⁷ (m ² · s) (Equation 4) When Expression 4 is represented by a unit generally used in liquid chromatography, (r ⁴ · L 2) / f <2.5 × 10 ⁻³ (mm ⁴ · m / (ml / min)) (Equation 5)

As can be seen from the above (Equation 2),
The spread σ ^{* in} units of time indicates that as the flow rate f increases,
Become smaller. That is, when given values of r and L2 are given, the influence of the spread σ ^* outside the column can be reduced by increasing the flow rate f.

The inner diameter r of a commonly used reaction coil
Is 0.33mm above 0.25mm
You. As is apparent from (Equation 2), the extension in units of time is
Σ ^*Is affected by the fourth power of the inner diameter r.
It is preferable that the diameter r is small.
It shall be 5 mm or less.

The longer the reaction coil length L2 is, the longer the reaction time is, the better in terms of sensitivity. However, as can be seen from the above (Equation 2), the longer the reaction coil length L2 is,
Is increased, the spread σ ^* increases, so that the length L2 is set to 10 m or less in view of a balance between the two.

As described above, the inner diameter r of the reaction coil is set to 0.25 mm or less and the length is set to 10 m or less.
When the flow rate f (ml / min) of the liquid flowing through the column that satisfies is satisfied, the flow rate f of the liquid flowing through the reaction coil is set so as to satisfy the condition of f ≧ 2.5 × 10 ⁻³ (ml / min).
It should be understood that

Here, when the linear velocity of the liquid flowing through the reaction coil under the above conditions is obtained, the inner diameter r of the reaction coil is obtained.
Is 0.25 mm and the flow rate f of the liquid flowing through the column is 2.5
At the time of × 10 ⁻³ (ml / min), the linear velocity is 20 (m
/ Min).

An embodiment of the present invention implemented on the basis of the above-described essential points of the present invention will be described below with reference to FIGS. 3 to 6, 8, and 9. FIG. 3 is a configuration diagram of an amino acid analyzer according to one embodiment of the present invention.

The first buffer solution 1, the second buffer solution 2, the third buffer solution 3, the fourth buffer solution 4 and the column regenerating solution 5 are sequentially selected by solenoid valves 6A, 6B, 6C, 6D and 6E. Is sent to the ammonia filter 8 by the buffer pump 7. Here, for example, when sending a mixed buffer solution in which the second buffer solution 2 and the third buffer solution 3 are mixed at a predetermined ratio,
The solenoid valves 6B and 6C operate alternately, and the details will be described later.

The buffer and the like that have passed through the ammonia filter 8 are sent to the separation column 1 via the autosampler 9. The amino acid sample introduced by the autosampler 9 is separated by the separation column 10. Each amino acid separated here is mixed with the ninhydrin reagent 11 sent by the ninhydrin pump 12 by the mixer 13 and reacted by the reaction coil 14. Amino acids that are colored by the reaction are continuously detected by the photometer 15, output as a chromatogram and data by the data processing device 16, and recorded and stored.

Next, the structure of a separation column filled with an ion exchange resin will be described with reference to FIG. FIG. 4 is a sectional view of a separation column used in the amino acid analyzer according to one embodiment of the present invention.

The column cylinder 21 is filled with an ion exchange resin 22. The filter 23 is press-fitted to the column cap 25 together with a ring seal 24 made of fluororesin.

When the column cap 25 is screwed into the column cylinder 21 after filling the column cylinder 21 with the ion exchange resin 22, the filter 23 is firmly fixed by the sealing property of the seal 24 so that the pressure resistance is maintained. Has become.
Further, the filter 23 is slightly inserted into the column tube 21 so that the filled ion exchange resin 22 and the filter 23 are in close contact with each other so that there is no gap.

A filter space 27, which is a counterbore-shaped gap, is formed between the filter 23 and the column cap 25. This filter space 27 is formed to improve the dispersion of the liquid flow. The provision of the filter space 27 guides the flow of the separated components even inside the filter 23 in a vertical and parallel manner, thereby preventing a reduction in resolution.

Connection hole 2 provided in column cap 25
6 is connected to a mixer.

The characteristic feature of the present embodiment lies in the structure of the separation column 10. For example, in the first example, the size of the separation column 10 has an inner diameter (ID) of 6.0 m.
m and the length is 40 mm.

The reason why the size of the separation column is set will be described below.

As described above, the conventional separation column (4.
In the case of (6 mm ID × 60 mm), it was found that as the buffer flow rate was increased for the purpose of shortening the analysis time, the column load pressure increased, and the relationship between the column load pressure and the buffer flow rate deviated from the linear relationship. The limit flow rate of the separation column that deviates from this linear relationship is experimentally 0.
It was found to be 6 ml / min. If the buffer solution can be flowed at a speed higher than this flow rate, the analysis time can be shortened, but the column load pressure becomes too high, so that it cannot be used in actual use.

Here, the inventor paid attention to the linear velocity of the buffer at this time. The reason is, experimentally,
When a separation column having an inner diameter of 4.6 mm and a length of 40 mm was used, it was thought that the limit flow rate was increased because the pressure of the separation column was reduced due to the shortened length.
The operating flow rate limit of the separation column was the same as 0.6 ml / min, despite the change in length.

When the buffer flow rate is 0.6 ml / min,
The linear velocity of this buffer is 36 mm / min. That is, the use limit of the separation column is not the flow rate of the buffer solution,
It is defined by the linear velocity, and its usage limit linear velocity is 36
mm / min. Therefore, the inner diameter of the separation column is increased from 4.6 mm to 6.0 mm from the viewpoint of increasing the buffer flow rate without exceeding the usage limit linear velocity.

By increasing the inner diameter of the separation column, the flow rate of the buffer solution can be increased, and the analysis time can be reduced.

At this time, in order to increase the column efficiency,
If the particle size of the ion-exchange resin is 3 μm as in the prior art, the particle size is small, and the pressure loss in the column becomes large. Therefore, in order to reduce this pressure loss, the total length of the separation column is shortened from 60 mm in the past to 40 mm. As the column length decreases, the number of theoretical plates decreases.
Extra-column spreading affects the separation, which can be solved by suppressing the spreading in the reaction coil which contributes to 80% of the extra-column spreading.

Based on such a concept, the inner diameter is 6 mm.
When the relationship between the buffer solution flow rate and the column pressure was examined using a separation column having a length of 40 mm, it was found that the relationship was as shown in FIG.

FIG. 5 shows the flow rate of the buffer solution when a separation column having an inner diameter of 6 mm, a length of 40 mm, and a particle size of the ion exchange resin to be packed of 3 μm is used in the amino acid analyzer according to one embodiment of the present invention. FIG. 4 is a diagram illustrating a relationship between column pressures.

In FIG. 5, the horizontal axis represents the buffer flow rate (ml / min) flowing through the separation column and the buffer linear velocity (mm / min) corresponding to this flow rate, and the vertical axis represents the load pressure of the separation column. (Kgf / cm ² ).

When the buffer solution flow rate was 0.2 ml / min (linear velocity 7 mm / min), the load pressure on the separation column was 19
kgf / cm ² . Buffer flow rate of 0.4ml / mi
The load pressure of the separation column at n (linear velocity 14 mm / min) is 39 kgf / cm ² . Buffer flow rate is 0.
The load pressure of the separation column at 6 ml / min (linear velocity 21 mm / min) is 58 kgf / cm ² . Buffer flow rate of 0.8 ml / min (linear speed 28 mm / mi
The load pressure of the separation column at the time of n) is 78 kgf / cm
² . Buffer flow rate is 1.0 ml / min (linear velocity 3
The load pressure of the separation column at 5 mm / min) is 98
kgf / cm ² .

That is, when the flow rate of the buffer solution is 1.0 ml / min.
It is understood that the relationship between the buffer solution flow rate (linear velocity) and the separation column load pressure is linear up to (linear velocity 35 mm / min).

As described above, since the use limit linear velocity is 36 mm / min, even if the buffer liquid flow rate is increased to 1.0 ml / min (linear velocity 35 mm / min), , Load pressure is 100kgf / c
Since it is m ² or less, it has been found that it can sufficiently withstand use from the viewpoint of load pressure.

The problem here is the separation rate when the analysis time is shortened by increasing the flow rate of the buffer solution in this manner. In this example, a standard analysis method in which the analysis time was shortened to an analysis time of 20 minutes was performed.

In this embodiment, an L-8500 Hitachi high-speed amino acid analyzer was used as the analyzer main body. The separation column is Hitachi Custom Ion Exchange Resin # 2
622-SC is used. The particle size of this Hitachi custom ion exchange resin # 2622-SC is 3 μm. As the ammonia filter column 8, Hitachi custom ion exchange resin # 2650L was used. As the reaction coil, a tube made of fluororesin having an inner diameter of 0.25 mm ID × 7 m was used.

The conditions for this analysis are as shown in Table 1. In Table 1, for comparison, analysis conditions for a 30-minute analysis by a conventional standard method are shown.

[0061]

[Table 1]

That is, as described above, the separation column has an inner diameter of 6.0 mm and a length of 40 mm. That is, the inner diameter is larger and the total length is shorter than that of the conventional 30-minute analysis. Further, in the separation column of such a size, the ratio (L1 / R) of the length L1 to the inner diameter R of the separation column is 6.6, and L1 / R is 10 or less.

In order to enable analysis for 20 minutes by the standard method, the flow rate of the buffer is set at 0.78 ml / min.
This flow rate is slightly higher than (30/20) times the buffer flow rate (0.46 ml / min) in the case of the conventional 30-minute analysis method. However, in terms of the column linear velocity of the buffer, in the 20-minute analysis method of this example,
27 mm / min, which is almost the same as 28 mm / min in the conventional 30-minute analysis method. Although the linear velocity of the column hardly changes, by increasing the inner diameter of the separation column, the flow rate of the buffer solution can be increased, and the analysis time can be shortened.

Although the linear velocity of the column hardly changed, the load pressure of the separation column was increased to 80 kgf / cm ² by increasing the inner diameter of the separation column. 110k pressure
gf / cm ² . Therefore, if the working limit load pressure is the same, this example can extend the life of the separation column.

As the buffer flow rate increased to 0.78 ml / min, the ninhydrin reagent flow rate increased to 0.60 ml / min.
ml / min.

Next, regarding the reaction coil, the size of the reaction coil itself is 0.25 mm in inner diameter and 7 m in length. As described above, this is selected under the condition that the inner diameter is 0.25 mm or less and the length is 10 m or less. The size of the reaction coil itself is the same as that of the conventional 30-minute analysis, but the total amount of the liquid flowing through the reaction coil, that is, the sum of the flow rates of the buffer solution and the ninhydrin reagent is 1.38 ml / min. And satisfies the condition of 1.0 ml / min or more. In the conventional 30-minute analysis, the total amount of the solution is
0.81 ml / min.

Since the mixture of the buffer and the ninhydrin reagent flows through the reaction coil, the flow rates of the buffer and the ninhydrin reagent are increased. As a result, the flow rates of the mixture and the ninhydrin reagent are also increased. The speed is 16.
From 5m / min to 28.2m / min,
It satisfies the condition of 20 m / min or more.

The value of (r ⁴ · L 2 / f) is also 1.2
4 × 10 ⁻³ (mm ⁴ · m / (ml / min)), which satisfies the requirement of 2.5 × 10 ⁻³ or less. The spread σ ^* at this time is 0.047 (min) (= 2.8
(S)) and 0.067 (min) (= 4 (s))
Meets the following requirements:

The size of the reaction coil was the same, and as a result of the increase in the linear velocity of the mixture, the reaction time was reduced from 0.42 minutes in the conventional 30-minute analysis method to 0.25 minutes. As a result, the sensitivity is slightly reduced, but this reduction in sensitivity is not a problem in practical use, and will be described later using a chromatogram of this standard 20-minute analysis.

As described above, the standard 20-minute analysis can be performed, but the point to be noted at that time is the separation rate. If the separation rate decreases even if the analysis time is shortened, it is not practical, but as described below, a sufficient separation rate is obtained in this example.

Next, the composition of the buffer used in the standard 20-minute analysis according to this example will be described with reference to Table 2.

[0072]

[Table 2]

In Table 2, PH-1 represents the composition of the first buffer, PH-2 represents the composition of the second buffer, and P
H-3 represents the composition of the third buffer, and PH-4 represents the composition of the fourth buffer.
RH-RG indicates the composition of the column regenerating solution.

The first buffer PH-1 has a Na concentration of 0.0
8N, with respect to about 700 ml of distilled water, 3.10 g of sodium citrate (2H ₂ O), 2.83 g of sodium chloride, 9.90 g of citric acid (H ₂ O), 150.0 ml of ethyl alcohol, 4. Thiodiglycol
0 ml, 4.0 ml of BRIJ-35, and 0. caprylic acid.
By dissolving 1 ml and further adding distilled water, the total volume is adjusted to 1.0 l (1000 ml). The pH of the first buffer PH-1 is 3.3 (nominal value).

The second buffer PH-2 and the third buffer PH-
3 has the same composition as the first buffer solution PH-1, but
The composition ratio was changed as shown in Table 2. Therefore, the sodium concentration of the second buffer PH-2 is 0.2 and the pH is 3.2. In addition, the third buffer PH-3
Has a sodium concentration of 0.2 and a pH of 4.0.

The fourth buffer PH-4 uses benzyl alcohol in place of ethyl alcohol and thiodiglycol of the first to third buffers, and the composition ratio is as shown in Table 2. The sodium concentration of the fourth buffer PH-4 is 1.2, and the pH is 4.9.

The regenerating solution RH-RG has a Na concentration of 0.2. For about 700 ml of distilled water, 8.00 g of sodium hydroxide, 100.0 ml of ethyl alcohol,
The total volume was adjusted to 1.0 l (1000 ml) by dissolving 4.0 ml of RIJ-35 and 0.1 ml of caprylic acid, and further adding distilled water.

Next, a description will be given, with reference to Table 3, of the analysis program showing the buffer switching timing and the selection of each buffer in the standard 20-minute analysis according to this example.

[0079]

[Table 3]

In Table 3, from the left, the step number, the execution time (minute) of each step, the flow rate of the buffer, and the temperature (° C.) of the separation column are shown. Steps 1-2, ie, 0.
From 0 minutes to 2.0 minutes, the solenoid valve V1 for flowing the first buffer solution
Is driven to flow the first buffer at 100%. At this time, the temperature of the separation column is controlled to 55 ° C.

Steps 3 and 4, ie, 2.1 minutes to 4.
Until 5 minutes, the solenoid valve V2 for flowing the second buffer and the solenoid valve V3 for flowing the third buffer are driven, and the total amount is 100% at a flow ratio of 90% of the second buffer: 10% of the third buffer. % Buffer solution. Since the solenoid valves V2 and V3 are driven by pulse width modulation, the conduction angle of the solenoid valve V2 is set to 9
0%, the conduction angle of the solenoid valve V3 is set to 10%, and the solenoid valve V3 is closed at the timing when the solenoid valve V2 is opened, and conversely, the solenoid valve V3 is opened at the timing when the solenoid valve V2 is closed. The flow rate ratio can be controlled. The temperature of the separation column at this time is also controlled to 55 ° C. The temperature of the separation column is still controlled at 55 ° C. Between steps 2 and 3, the first buffer 100
%, Gradually changes from 90% in the second buffer solution to 10% in the third buffer solution, and is gradient.

Steps 5 to 6, ie, 4.6 minutes to 1
Until 0.0 minutes, the solenoid valve V3 for flowing the third buffer is driven to flow 100% of the third buffer. Between steps 4 and 5, 90% of the second buffer is used and 10% of the third buffer is used.
%, And gradually changes to a 100% state of the third buffer solution, and is gradient.

Steps 7 and 8, ie, 10.1 minutes to 1
Until 7.5 minutes, the solenoid valve V4 for flowing the fourth buffer is driven to flow 100% of the fourth buffer. Between step 6 and step 7, the state of the third buffer 100% is changed to the fourth buffer.
The state gradually changes to a state of 100% buffer, and is gradient.

In steps 9 to 10, ie, from 17.6 minutes to 21.0 minutes, the solenoid valve V5 for flowing the regenerating liquid is driven to flow 100% of the regenerating liquid. Between step 8 and step 9, the regenerating solution 1
It gradually changes to a state of 00% and is gradient. Although the analysis time is 20 minutes, the regenerating solution is sent from 17.6 minutes in consideration of the delay of the separation column.

In steps 11 to 12, ie, from 21.1 minutes to 22.0 minutes, the solenoid valve V through which the second buffer solution flows is again supplied.
2 is driven to flow 100% of the second buffer. Step 1
Between 0 and step 11, the state of the regenerating solution 100% gradually changes to the state of the second buffer solution 100%, and the gradient is obtained. Here, the second buffer solution is used for washing a substance that stays downstream of the electromagnetic valve.

In steps 13 and 14, ie, from 22.1 minutes to 33.0 minutes, the solenoid valve V through which the first buffer solution flows is again supplied.
1 is driven to flow 100% of the first buffer solution. Step 1
Between step 2 and step 13, the second buffer 100%
From the state of the first buffer 100% gradually,
Gradient. Here, the first buffer is used to fill the channel system with the first buffer and equilibrate the inside of the column in preparation for the next measurement.

Next, FIG. 6 shows a chromatogram obtained by analyzing 18 amino acids of the protein hydrolyzate contained in the standard sample according to this example, and FIG. 7 shows a conventional sample obtained by analyzing the same standard sample. 1 shows the chromatogram when analyzed using the standard 30-minute analysis method described above. The horizontal axes of FIGS. 6 and 7 each indicate time (min).

As is clear from FIG. 6, the analysis of the 18 components was completed in 20 minutes. In the conventional standard 30-minute analysis method shown in FIG. 7, the analysis requires 30 minutes. That is, in the present embodiment, at a high speed of 20 minutes by the standard method, 1
It enables analysis of eight components.

As is apparent from a comparison of FIGS. 6 and 7, this example shows a better separation of chromatographic peaks between Asp (aspartic acid) and Ala (alanine). As an index for determining the degree of chromatogram separation, a Thr (threonine) -Ser (serine) separation rate and a Gly (glycine) -Ala (alanine) separation rate are generally used. Table 4 shows the separation rates shown in FIGS. 6 and 7 calculated based on these separation rates.

[0090]

[Table 4]

In the conventional standard 30-minute analysis method shown in FIG.
The separation ratio of Thr (threonine) -Ser (serine) is as follows:
In contrast to 89%, in the present embodiment, the separation rate is improved to 99%. Gly (glycine) -A
The separation ratio of la (alanine) is 95% in the conventional standard 30-minute analysis method, whereas the separation ratio in this example is improved to 100%.

That is, as is clear from the comparison between FIG. 6 and FIG. 7, in this embodiment, the standard analysis can be performed at a high speed of 20 minutes, and the separation rate is improved as compared with the conventional standard 30-minute analysis. Can be done.

[0093] In Example 2 in Table 4,
It will be described later.

In the embodiment of FIG. 6, the height of the chromatographic peak is slightly lower. This is because, as shown in Table 1, the linear velocity of the mixture flowing through the reaction coil increases due to the increase in the flow rate of the buffer and the flow rate of the ninhydrin reagent.
This is the effect shortened to 25 minutes. However, since the chromatographic peak area method is used for the quantification of the analyzed amino acid components, the influence of the decrease in the peak height is small, and rather, the chromatographic peak separation rate is improved.
Since the two peaks can be separated and the areas can be obtained more accurately, the measurement accuracy is not reduced.

According to the present embodiment described above, a 20-minute analysis by the standard method, which was conventionally impossible, has become possible.

At this time, the separation rate was also improved as compared with the conventional 30-minute standard method analysis.

Further, since the pressure of the separation column is lower than that in the conventional 30-minute standard method analysis, the life can be extended.

Next, a second embodiment of the present invention will be described. This example also enables analysis for 20 minutes by the standard method.

Also in this example, the amino acid analyzer having the structure shown in FIG. 3 is used, and the structure of the separation column shown in FIG. 4 is used.

As the main body of the analyzer, a model L-8500 Hitachi high-speed amino acid analyzer was used. In the separation column,
Hitachi custom ion exchange resin # 2622-SC is used. This Hitachi custom ion exchange resin # 2622-S
The particle size of C is 3 μm. The ammonia filter column 8 is made of Hitachi custom ion exchange resin # 26.
50 L was used.

The conditions for this analysis are as shown in Table 5.

[0102]

[Table 5]

That is, as described above, the separation column has an inner diameter of 6.0 mm and a length of 30 mm. That is, the inner diameter is the same as that of the first embodiment, but a shorter length is used. In a separation column of such a size, the ratio of the length L1 of the separation column to the inner diameter R (L1 / L
R) is 5.0, and L1 / R is 10 or less.

In order to enable analysis for 20 minutes by the standard method, the flow rate of the buffer is set to 0.59 ml / min.
This flow rate is about ／ of that in Example 1. Although the flow rate is reduced by the shortened length of the separation column, the flow rate is made faster than the conventional example of 0.46 ml / min. As a result, the analysis time can be reduced. As for the column linear velocity of the buffer solution, as described above, the usable limit linear velocity is 36 mm / min. Therefore, 21 mm / min in this embodiment is a value within the usable limit linear velocity.

Further, as a result of the lower column linear velocity as compared with Example 1, the load pressure on the separation column was 50 kgf.
/ Cm ² , compared to the 20 minute analysis method of Example 1.
Can be lowered. Therefore, if the working limit load pressure is the same, this example can extend the life of the separation column.

The size of the reaction coil itself is 0.25 mm in inner diameter and 7 m in length. The total amount of the liquid flowing through the reaction coil is 1.09 ml / min, which satisfies the condition of 1.0 ml / min or more.

Since the mixture of the buffer solution and the ninhydrin reagent flows through the reaction coil, the linear velocity of the mixture in the reaction coil is 22.3 m / min.
It satisfies the condition of 0 m / min or more.

The value of (r ⁴ · L 2 / f) is also 1.5
7 × 10 ⁻³ (mm ⁴ · m / (ml / min)), which satisfies the requirement of 2.5 × 10 ⁻³ or less. The spread σ ^* at this time is 0.054 (min) (= 3.2
(S)) and 0.067 (min) (= 4 (s))
Meets the following requirements:

The size of the reaction coil was the same, and the linear velocity of the mixed solution was reduced.
It extends from 25 minutes to 0.33 minutes. As a result,
The sensitivity will increase somewhat.

As described above, the standard 20-minute analysis can be performed, but the point to be noted at that time is the separation rate. If the separation rate decreases even if the analysis time is shortened, it is not practical, but as described below, a sufficient separation rate is obtained in this example.

Next, the composition of the buffer used in the standard 20-minute analysis according to this example is the same as that used in Example 1,
The same buffers and regenerating solutions as described in Table 2 were used.

Next, the analysis program indicating the buffer switching timing and the selection of each buffer in the standard 20-minute analysis according to this example is the same as that used in Example 1, and is described in Table 3. Use the same analysis program.

As described above, when the chromatogram is obtained and the separation rate is obtained by calculation, the result is as shown in Table 4 above.

That is, according to the conventional standard 30-minute analysis method shown in FIG. 7, the separation ratio of Thr (threonine) -Ser (serine) is 89%, whereas the separation ratio in the present embodiment is 89%. It has increased to 91%. The separation rate of Gly (glycine) -Ala (alanine) is 30
In the present embodiment, the separation rate is improved to 99%, whereas the separation analysis is 95%.

That is, in this embodiment, the speed of the standard analysis can be increased by 20 minutes, and the separation rate can be improved as compared with the conventional standard 30-minute analysis.

As is clear from the comparison in Table 4, the separation rate of Thr (threonine) -Ser (serine) was improved to 99% by the standard 20-minute analysis method of Example 1, whereas In this example, the separation rate is 91%, and Gly (glycine) -Ala (alanine)
Is 100% in the standard 20-minute analysis method of Example 1.
%, In the present embodiment, the separation rate is 99%.
%, Which is lower than that of Example 1 in the separation rate of the present example.

This is due to the effect of lowering the flow rate of the buffer solution. Although a slight decrease in the separation rate is observed, the separation rate is higher than in the conventional case.

According to the present embodiment described above, it has become possible to perform a 20-minute analysis by the standard method, which was conventionally impossible.

At this time, the separation rate is also improved as compared with the conventional 30-minute standard method analysis.

Further, since the pressure of the separation column is lower than that in the conventional 30-minute standard method analysis, the life can be extended.

Next, a third embodiment of the present invention will be described. This example enables analysis for 20 minutes by the standard method.

Also in this example, the amino acid analyzer having the structure shown in FIG. 3 is used, and the structure of the separation column shown in FIG. 4 is used.

As the analyzer main body, an L-8500 type Hitachi high-speed amino acid analyzer was used. In the separation column,
Hitachi custom ion exchange resin # 2622-SC is used. This Hitachi custom ion exchange resin # 2622-S
The particle size of C is 3 μm. The ammonia filter column 8 is made of Hitachi custom ion exchange resin # 26.
50 L was used.

The conditions of this analysis are as shown in Table 5. That is, as described above, the column size of the separation column is 5.0 mm in inner diameter and 50 mm in length. That is, as compared with the first embodiment, the inner diameter is narrower and the length is longer. In a separation column of such a size, the ratio of the length L1 of the separation column to the inner diameter R (L1 / R)
Is 10.0, and L1 / R is 10 or less.

In order to enable analysis for 20 minutes by the standard method, the flow rate of the buffer is set to 0.68 ml / min.
At this time, the column linear velocity of the buffer was 35 mm / m
in, the usage limit linear velocity is 36 mm / mi
Since it is n, 35 mm / min in the present embodiment is a value within this use limit linear velocity. That is, in this example,
The buffer flow rate is set so as to be within the limit of the usable linear velocity.

Further, as a result of increasing the column linear velocity as compared with Example 1, the load pressure on the separation column was 110 kg.
f / cm ² , which is higher than the 20-minute analysis method of Example 1, but is the same as the load pressure of the conventional example, so that the same life as the conventional one can be obtained.

The size of the reaction coil itself is 0.25 mm in inner diameter and 7 m in length. The total amount of the liquid flowing through the reaction coil is 1.23 ml / min, which satisfies the condition of 1.0 ml / min or more.

Since the mixture of the buffer solution and the ninhydrin reagent flows through the reaction coil, the linear velocity of the mixture in the reaction coil is 25.2 m / min.
It satisfies the condition of 0 m / min or more.

The value of (r ⁴ · L 2 / f) is also 1.3.
9 × 10 ⁻³ (mm ⁴ · m / (ml / min)), which satisfies the requirement of 2.5 × 10 ⁻³ or less. The spread σ ^* at this time is 0.050 (min) (= 3.0
(S)) and 0.067 (min) (= 4 (s))
Meets the following requirements:

The size of the reaction coil was the same, and the linear velocity of the mixed solution was reduced.
It extends from 25 minutes to 0.29 minutes. As a result,
The sensitivity will increase somewhat.

As described above, the standard 20-minute analysis can be performed. At this time, a point to be noted is a separation rate. If the separation rate decreases even if the analysis time is shortened, it is not practical, but as described below, a sufficient separation rate is obtained in this example.

Next, the composition of the buffer used in the standard 20-minute analysis according to this example is the same as that used in Example 1,
The same buffers and regenerating solutions as described in Table 2 were used.

Next, the buffer switching timing of the standard 20-minute analysis according to this example and the analysis program indicating the selection of each buffer are the same as those used in Example 1, and are described in Table 3. Use the same analysis program.

As described above, when the chromatogram is obtained and the separation ratio is obtained by calculation, the result is as shown in Table 4 above.

That is, in the conventional standard 30-minute analysis method shown in FIG. 7, the separation ratio of Thr (threonine) -Ser (serine) is 89%, whereas the separation ratio in the present embodiment is 89%. It has increased to 90%. The separation rate of Gly (glycine) -Ala (alanine) is 30
In the present embodiment, the separation rate is improved to 98%, whereas the separation analysis is 95%.

That is, in this embodiment, the standard analysis can be performed at a high speed of 20 minutes, and the separation rate can be improved as compared with the conventional standard 30-minute analysis.

As is apparent from the comparison in Table 4, the separation rate of Thr (threonine) -Ser (serine) was improved to 99% by the standard 20-minute analysis method of Example 1, whereas In this embodiment, the separation rate is 90%, and Gly (glycine) -Ala (alanine)
Is 100% in the standard 20-minute analysis method of Example 1.
%, In the present embodiment, the separation rate is 98%.
%, Which is lower than that of Example 1 in the separation rate of the present example.

This is due to the effect of lowering the flow rate of the buffer solution. Although a slight decrease in the separation rate is observed, the separation rate is higher than in the conventional case.

According to the present embodiment described above, it has become possible to perform a 20-minute analysis by the standard method, which was conventionally impossible.

At this time, the separation rate is also improved as compared with the conventional 30-minute standard method analysis.

Further, the pressure of the separation column is equivalent to that in the conventional 30-minute standard method analysis, and the same life can be obtained.

Next, a fourth embodiment of the present invention will be described. This example allows for a 15 minute analysis by the standard method.

Also in this example, the amino acid analyzer having the structure shown in FIG. 3 is used, and the structure of the separation column shown in FIG. 4 is used.

As the main body of the analyzer, an L-8500 Hitachi high-speed amino acid analyzer was used. In the separation column,
Hitachi custom ion exchange resin # 2622-SC is used. This Hitachi custom ion exchange resin # 2622-S
The particle size of C is 3 μm. The ammonia filter column 8 is made of Hitachi custom ion exchange resin # 26.
50 L was used.

The conditions for this analysis are as shown in Table 6. Note that Table 5 shows Example 1 for comparison.
The analysis conditions for the 20-minute analysis are shown by the standard method indicated by.

[0146]

[Table 6]

That is, as described above, the separation column has an inner diameter of 6.0 mm and a length of 40 mm. That is, it is of the same size as the first embodiment. Also,
In the separation column having such a size, the ratio (L1 / R) of the length L1 of the separation column to the inner diameter R is 6.6,
1 / R is 10 or less.

In order to enable analysis for 15 minutes by the standard method, the flow rate of the buffer solution is set to 0.97 ml / min.
This flow rate is slightly lower than (20/15) times the buffer flow rate (0.78 ml / min) in the case of the 20-minute analysis method of Example 1. In terms of the column linear velocity of the buffer, in the 15-minute analysis method of this example, 35 mm / m
in, which is 28 mm / of the conventional 30 minute analysis method.
min, but by increasing the inner diameter of the separation column, the buffer flow rate can be increased,
The analysis time has been shortened. As described above, regarding the column linear velocity of the buffer solution,
Since it is 6 mm / min, 35 mm / min
min is a value within this use limit linear velocity.

Also, compared to the first embodiment, the column linear velocity
As a result, the load pressure of the separation column was 100 kgf.
/ Cm²Which is higher than the 20-minute analysis method.
The separation column in the conventional 30-minute analysis method
Load pressure 110kgf / cm ²Can be lower
You. Therefore, if the operating limit load pressure is the same,
The example can extend the life of the separation column.
You.

As the flow rate of the buffer solution was increased to 0.97 ml / min, the flow rate of the ninhydrin reagent was increased to 0.80 ml / min.
ml / min.

The size of the reaction coil itself is 0.25 mm in inner diameter and 7 m in length. The total amount of the liquid flowing through the reaction coil is 1.77 ml / min, which satisfies the condition of 1.0 ml / min or more.

Since the mixture of the buffer solution and the ninhydrin reagent flows through the reaction coil, the flow rates of the buffer solution and the ninhydrin reagent are increased. The speed is 35.
1 m / min, which satisfies the condition of 20 m / min or more.

The value of (r ⁴ · L 2 / f) is also 9.6.
6 × 10 ⁻⁴ (mm ⁴ · m / (ml / min)), which satisfies the requirement of 2.5 × 10 ⁻³ or less. The spread σ ^* at this time is 0.042 (min) (= 2.5
(S)) and 0.067 (min) (= 4 (s))
Meets the following requirements:

The size of the reaction coil was the same, and the linear time of the mixed solution was increased.
It has been reduced from 25 minutes to 0.19 minutes. As a result, the sensitivity is slightly reduced, but this reduction in sensitivity is not a problem in practical use, and will be described later using a chromatogram of this standard 15-minute analysis.

As described above, the standard 15-minute analysis can be performed, but the point to be noted at that time is the separation rate. If the separation rate decreases even if the analysis time is shortened, it is not practical, but as described below, a sufficient separation rate is obtained in this example.

Next, the composition of the buffer solution used in the standard 15-minute analysis according to this example is the same as that used in Example 1,
The same buffers and regenerating solutions as described in Table 2 were used.

Next, the buffer switching timing of the standard 15-minute analysis and the analysis program indicating the selection of each buffer according to this example are the same as those used in Example 1 and are described in Table 3. Use the same analysis program.

Next, FIG. 8 shows a chromatogram obtained by analyzing 18 amino acids of the protein hydrolyzate contained in the standard sample according to the present example.

The horizontal axis of FIG. 8 indicates time, and the time axis scale is the same as that of the first embodiment shown in FIG.

As is clear from FIG. 8, the analysis of the 18 components was completed in 15 minutes. That is, in the present embodiment, analysis of 18 components is enabled at a high speed of 15 minutes by the standard method.

As is clear from a comparison between FIG. 8 and FIG. 7 of the conventional example, this example shows a better separation of chromatographic peaks between Asp (aspartic acid) and Ala (alanine). As an index for determining the degree of chromatogram separation, generally, Thr (threonine) -Ser
(Serine) separation rate, Gly (glycine) -Ala
(Alanine) separation rate is used. Table 7 shows the calculated separation rates shown in FIG. 7 based on these separation rates.

[0162]

[Table 7]

That is, in the conventional standard 30-minute analysis method shown in FIG. 6, the separation ratio of Thr (threonine) -Ser (serine) is 89%, whereas the separation ratio in this embodiment is 89%. It has increased to 93%. The separation rate of Gly (glycine) -Ala (alanine) is 30
In the present example, the separation rate was improved to 97%, compared with 95% in the fraction analysis method.

That is, as is clear from the comparison between FIG. 8 and FIG. 7, in this embodiment, the standard analysis can be performed at a high speed of 15 minutes, and the separation rate can be improved as compared with the conventional standard 30-minute analysis. Can be done.

As is clear from the comparison in Table 7, the separation rate of Thr (threonine) -Ser (serine) was improved to 99% by the standard 20-minute analysis method of Example 1, whereas In this example, the separation rate is 93%, and Gly (glycine) -Ala (alanine)
Is 100% in the standard 20-minute analysis method of Example 1.
%, In this example, the separation rate was 97%.
%, Which is lower than that of Example 1 in the separation rate of the present example.

This is an effect of further increasing the flow rate of the buffer solution, and although the separation rate is slightly reduced, the separation rate is higher than in the conventional case.

When FIG. 8 and FIG. 6 are compared, FIG.
The height of the chromatographic peak of the example of FIG. 6 is higher than the height of the chromatographic peak of the example of FIG. 6 because the time axis was compressed from 20 minutes to 15 minutes. When quantifying using the area method,
Although the quantification accuracy is slightly lower than that in FIG. 6, it is not lower than the conventional standard 30-minute analysis method.

According to the present embodiment described above, a 15-minute analysis by the standard method, which was conventionally impossible, has become possible.

At this time, the separation rate is also improved as compared with the conventional 30-minute standard method analysis.

Further, since the pressure of the separation column is lower than that in the conventional 30-minute standard method analysis, the life can be extended.

Next, a fifth embodiment of the present invention will be described. This example is applied to a biological fluid method, and enables analysis for 60 minutes by the biological fluid method.

Also in this example, the amino acid analyzer having the structure shown in FIG. 3 was used, and the structure of the separation column shown in FIG. 4 was used.

As the main body of the analyzer, a model L-8500 Hitachi high-speed amino acid analyzer was used. In the separation column,
Hitachi custom ion exchange resin # 2622-SC is used. This Hitachi custom ion exchange resin # 2622-S
The particle size of C is 3 μm. The ammonia filter column 8 is made of Hitachi custom ion exchange resin # 26.
50L is used.

The conditions for this analysis are as shown in Table 8. Table 8 shows, for comparison, the analysis conditions of the conventional biological fluid method for 110-minute analysis.

[0175]

[Table 8]

That is, as described above, the separation column has an inner diameter of 6.0 mm and a length of 40 mm. That is, the inner diameter is larger and the overall length is shorter than that of the conventional 110-minute analysis. Further, it has the same size as that of the first embodiment. In a separation column of such a size, the ratio of the length L1 of the separation column to the inner diameter R (L1 / L
R) is 6.6, and L1 / R is 10 or less.

In order to enable analysis for 60 minutes by the biological fluid method, the flow rate of the buffer solution is set to 0.78 ml / min. This flow rate is slightly faster than (110/60) times the buffer flow rate (0.35 ml / min) in the conventional 110 minute analysis method. This flow rate is the same as the standard 20-minute method of Example 1. In terms of the column linear velocity of the buffer, 27 mm /
min, which is 21 m of the conventional 110 minute analysis method.
Although the speed is slightly higher than m / min, the flow rate of the buffer solution can be increased and the analysis time can be shortened by increasing the inner diameter of the separation column. As for the column linear velocity of the buffer solution, as described above, the use limit linear velocity is 36 mm / min.
7 mm / min is a value within the use limit linear velocity.

Although the linear velocity of the column was increased, the internal pressure of the separation column was increased, so that the load pressure of the separation column was 110 kgf / cm 2, which was 100 kgf / cm ^{2 in} the conventional 110-minute analysis method.
^Although slightly higher than ^2, the degree of increase in the separation column load pressure is suppressed compared to the increase in the flow rate. In addition, such an increase in the pressure does not require a significant effect on the life of the separation column.

As the buffer flow rate increased to 0.78 ml / min, the ninhydrin reagent flow rate increased to 0.60 ml / min.
ml / min.

Next, the size of the reaction coil was 0.2 mm in inner diameter.
5 mm and 7 m in length are used. Since the mixture of the buffer and the ninhydrin reagent flows through the reaction coil, the flow rates of the buffer and the ninhydrin reagent are increased. As a result, the flow rate of the mixture is also increased, and the linear velocity of the mixture in the reaction coil is 13. 38.2m / min to 28.2
m / min, which satisfies the condition of 20 m / min or more.

The value of (r ⁴ · L 2 / f) is also 1.2
4 × 10 ⁻³ (mm ⁴ · m / (ml / min)), which satisfies the requirement of 2.5 × 10 ⁻³ or less. The spread σ ^* at this time is 0.047 (min) (= 2.8
(S)) and 0.067 (min) (= 4 (s))
Meets the following requirements:

The size of the reaction coil is the same, and as a result of the increase in the linear velocity of the mixture, the reaction time has been reduced from 0.53 minutes in the conventional 110-minute analysis method to 0.25 minutes. As a result, the sensitivity is slightly reduced, but this reduction in sensitivity is not a problem in practical use.
This will be described later using the chromatogram of the 0-minute analysis.

As described above, the analysis of the biological fluid for 60 minutes is possible, but the point to be noted at that time is the separation rate. If the separation rate decreases even if the analysis time is shortened, it is not practical, but as described below, in this example,
A sufficient separation rate has been obtained.

Next, the composition of the buffer used in the biological fluid 60-minute analysis according to this example will be described with reference to Table 9.

[0185]

[Table 9]

In Table 9, PF-1 indicates the composition of the first buffer, PF-2 indicates the composition of the second buffer, and P
F-3 represents the composition of the third buffer, and PF-4 represents the composition of the fourth buffer.
PF-RG indicates the composition of the column regenerating solution.

The first buffer PF-1 has a Li concentration of 0.0
9N, 5.73 g of lithium citrate (4H ₂ O) and 1.2
4 g, 19.90 g of citric acid (H ₂ O), 30.0 ml of ethyl alcohol, and 5.0 m of thiodiglycol
1, 4.0 ml of BRIJ-35, 0.1 m of caprylic acid
is dissolved and further distilled water is added to make the total volume 1.0 l (1000 ml). The pH of the first buffer PF-1 is 2.8 (nominal value).

The second buffer PF-2 is the same as the first buffer PF-
It has the same composition as 1 but the composition ratio was changed as shown in Table 7. Therefore, the second buffer PF-2
Has a lithium concentration of 0.225 and a pH of 3.7.

The third buffer PF-3 is the same as the first buffer PF-
In this example, 3.0 ml of benzyl alcohol was added in place of thiodiglycol 1 and the composition ratio is as shown in Table 7. Therefore, the lithium concentration of the third buffer PF-3 is 0.721 and the pH is 3.6.

The fourth buffer PF-4 was obtained by removing ethyl alcohol and thiodiglycol from the first buffer, and the composition ratio is as shown in Table 7. The lithium concentration of the fourth buffer PF-4 is 1.00, and the pH is
4.1.

The regenerating solution PF-RG has a Li concentration of 0.20
8.40 g of lithium hydroxide, 30.0 ml of ethyl alcohol, BR
4.0 ml of IJ-35 and 0.1 ml of caprylic acid were dissolved, and distilled water was added to adjust the total amount to 1.
0 l (1000 ml).

Next, a description will be given, with reference to Table 10, of the analysis program showing the switching timing of the buffer solution and the selection of each buffer solution in the biological fluid 60-minute analysis according to this example.

[0193]

[Table 10]

In Table 10, from the left, the step number, the execution time (minute) of each step, the flow rate of the buffer solution, and the temperature (° C.) of the separation column are shown.

Steps 1 to 3, ie, from 0.0 minutes to 1
Until 0.0 minutes, the solenoid valve V1 for flowing the first buffer is driven to flow 100% of the first buffer. At this time, the temperature of the separation column is controlled to be 38 ° C. in 0.0 minutes in Step 1, but is lowered to 31 ° C. in 2.0 minutes in Step 2 to control the temperature.

In step 4, ie, 10.1 minutes, the first
Solenoid valve V1 for flowing buffer and solenoid valve V for flowing second buffer
2 is driven to flow the buffer solution at a flow rate ratio of the first buffer solution 80%: the second buffer solution 20% so that the total amount becomes 100%. Since the solenoid valves V1 and V2 are driven by pulse width modulation, the conduction angle of the solenoid valve V1 is set to 80%, the conduction angle of the solenoid valve V2 is set to 20%, and the solenoid valve V2 is opened at the timing when the solenoid valve V1 is opened. Is closed, and conversely, by opening the solenoid valve V2 at the timing of closing the solenoid valve V1, the flow ratio can be controlled. The temperature of the separation column was 3
The temperature is controlled to 1 ° C. Between step 3 and step 4, the state of the first buffer 100% is gradually changed from the state of the first buffer 80% to the state of the second buffer 20%,
Gradient.

From step 4 to step 6, ie, 1
From 0.1 minute to 16.8 minutes, a gradient is performed in which the flow ratio of the first buffer to the second buffer is gradually changed. In step 4, that is, at 10.1 minutes, the solenoid valve V1 for flowing the first buffer and the solenoid valve V2 for flowing the second buffer are driven, and the first valve is driven.
At a flow rate of 80% of the buffer: 20% of the second buffer, the buffer is allowed to flow so that the total amount becomes 100%. On the other hand, in 16.8 minutes of Step 6, the first buffer 70%: At a flow rate ratio of the second buffer 30%, the total amount becomes 100%,
Run the buffer. From step 4 to step 6, that is,
From 10.1 minutes to 16.8 minutes, a gradient is performed in which the flow ratio of the first buffer to the second buffer is gradually changed.

Step 5 on the way, that is, 1
At 1.0 minute, temperature control is performed to increase the temperature to 58 ° C.

Steps 7 to 9, ie, 16.9 minutes to 2
Up to 2.0 minutes, the solenoid valve V1 for flowing the first buffer and the second valve
By driving the solenoid valve V2 for flowing the buffer, the first buffer 10
%: At a flow rate ratio of the second buffer solution of 90%, the buffer solution is flowed so that the total amount becomes 100%. Between step 6 and step 7, the state of the first buffer solution is 70% and the second buffer solution is 30%, and the state of the first buffer solution is 10% and the second buffer solution is 90%. Is done. Further, in Step 8 on the way, that is, at 17.5 minutes, temperature control for controlling the temperature to 40 ° C. is performed.

In steps 10 to 12, ie, from 22.1 minutes to 25.0 minutes, the solenoid valve V2 for flowing the second buffer is driven to flow 100% of the second buffer. Between step 9 and step 10, the state is gradually changed from the state of the first buffer 10% to the state of the second buffer 90% to the state of the second buffer 100%, and is gradient. Also, in step 11 on the way, that is, at 23.0 minutes, temperature control is performed so that the temperature is 70 ° C.

In steps 13 to 15, ie, from 25.1 minutes to 35.5 minutes, the solenoid valve V3 for flowing the third buffer is driven to flow 100% of the third buffer. Between step 12 and step 13, the state is gradually changed from the state of the second buffer 100% to the state of the third buffer 100%, and is gradient. Step 14 in the middle, ie, 3
At 4.5 minutes, temperature control is performed to set the temperature to 45 ° C.

In steps 16 to 17, that is, from 35.6 minutes to 38.5 minutes, the solenoid valve V1 for flowing the first buffer and the solenoid valve V4 for flowing the fourth buffer are driven, and the first buffer 6
0%: The flow rate ratio of the fourth buffer solution is 40%, and the total amount is 100%.
Pour the buffer so that Between step 15 and step 16, from the state of 100% of the third buffer,
The state gradually changes to a state of 40% of the fourth buffer with 60% of the first buffer, and the gradient is obtained.

In steps 18 to 19, that is, from 38.6 minutes to 44.0 minutes, the solenoid valve V4 for flowing the fourth buffer is driven to flow 100% of the fourth buffer. Between step 17 and step 18, the state gradually changes from a state of 60% of the first buffer to a state of 40% of the fourth buffer to a state of 100% of the fourth buffer, and is gradient.

In steps 20 to 22, that is, from 44.1 minutes to 52.0 minutes, the solenoid valve V2 for flowing the second buffer and the solenoid valve V4 for flowing the fourth buffer are driven to drive the second buffer 2
0%: the flow rate ratio of the fourth buffer solution 80%, the total amount is 100%
Pour the buffer so that Between steps 19 and 20, from the state of 100% of the fourth buffer,
The state gradually changes to a state of 80% of the fourth buffer with 20% of the second buffer, and is gradient. Step 2 in the middle
At 1, that is, at 48.0 minutes, temperature control for controlling the temperature to 70 ° C. is performed.

In steps 23 to 24, that is, from 52.1 minutes to 57.5 minutes, the solenoid valve V4 for flowing the fourth buffer is driven to flow 100% of the fourth buffer. Between step 22 and step 23, the state is gradually changed from the state of 80% of the fourth buffer with 20% of the second buffer to the state of 100% of the fourth buffer, and is gradient.

In steps 25 to 26, that is, from 57.6 minutes to 63.0 minutes, the solenoid valve V5 for flowing the regenerating solution is driven to flow 100% of the column regenerating solution. Between step 24 and step 25, the state is gradually changed from the state of 100% of the fourth buffer to the state of 100% of the regenerating solution, and the gradient is obtained. By flowing the column regenerating solution into the separation column, the separation column is washed and the column is regenerated.

In steps 27 to 28, that is, from 63.1 minutes to 80.0 minutes, the solenoid valve V1 for flowing the first buffer is driven to flow 100% of the first buffer. Between step 26 and step 27, the state is gradually changed from the state of the column regenerating solution 100% to the state of the first buffer solution 100%, and the gradient is obtained. Step 27, that is, 63.
In one minute, temperature control is performed to bring the temperature to 38 ° C. By flowing the first buffer, the channel system is filled with the first buffer,
The separation column is equilibrated and the temperature is the initial temperature 3
By setting the temperature at 8 ° C., the sample is prepared for the next analysis.

Next, FIG. 9 shows a chromatogram obtained by analyzing the amino acids of the biological fluid amino acid analog contained in the standard sample according to the present example, and FIG.
The chromatogram obtained when the same standard sample was analyzed using a conventional biological fluid 110-minute analysis method is shown. The horizontal axes of FIGS. 9 and 10 each indicate time.

As is clear from FIG. 9, the analysis of all components is completed in 60 minutes. In the conventional biological fluid 110-minute analysis method shown in FIG. 10, the analysis requires 110 minutes. That is, in the present embodiment, the biological fluid analysis method
The analysis can be performed in a minute, that is, about half the time as before. As is apparent from a comparison between FIGS. 9 and 10, Asp (aspartic acid) to Ala (alanine)
In this example, this example shows a better separation of chromatographic peaks. As an index for determining the degree of chromatogram separation, a Thr (threonine) -Ser (serine) separation rate and a Gly (glycine) -Ala (alanine) separation rate are generally used. Table 11 shows the separation ratios shown in FIGS. 9 and 10 calculated based on these separation ratios.

[0210]

[Table 11]

In the conventional biological fluid 110 minute analysis method shown in FIG. 10, the separation ratio of Thr (threonine) -Ser (serine) is 96%, whereas in the present embodiment, the separation ratio is 98%. % Has improved. The separation rate of Gly (glycine) -Ala (alanine) is the same as that of the conventional biological fluid 1
In the present example, the separation rate is improved to 99%, whereas the separation rate is 98% in the 10-minute analysis method.

That is, as is clear from the comparison between FIG. 9 and FIG. 10, in this embodiment, the biological fluid analysis can be speeded up for 60 minutes.
In addition, the separation rate can be improved as compared with the conventional case of analyzing the biological fluid for 110 minutes.

In the embodiment shown in FIG. 9, the height of the chromatographic peak is slightly higher. This is because the time axis of the horizontal axis was compressed. Since the chromatographic peak area method was used for the quantification of the analyzed amino acid components, the separation rate of the chromatographic peaks was improved and the two peaks were separated. In addition, since the areas can be more accurately obtained, no reduction in measurement accuracy is observed.

According to the present embodiment described above, it has become possible to perform a 60-minute analysis by the biological fluid method, which was conventionally impossible.

At this time, the separation ratio is also improved as compared with the conventional 110-minute biological fluid analysis.

The following is a summary of the present invention based on the above examples.

That is, it is considered that the use limit of the separation column depends not on the flow rate of the buffer but on the linear velocity of the column. In order to shorten the analysis time, the flow rate of the buffer is not exceeded without exceeding the linear velocity. As an increasing method, the inner diameter of the separation column was increased. Incidentally, the flow rate of the buffer solution flowing through the separation column having a column inner diameter of 4.6 mm was 0.6.
The column linear velocity at the time of ml / min is 36 mm / mi
n.

Therefore, as shown in each of the above examples, the flow rate of the buffer solution can be increased by increasing the inner diameter of the separation column, and the analysis time is 20 minutes for the standard method, 15 minutes for the standard method, The time can be reduced to 60 minutes, and high-speed analysis can be performed.

At this time, in order to increase the column efficiency,
If the particle size of the ion-exchange resin is 3 μm as in the prior art, the particle size is small, and the pressure loss in the column becomes large. Therefore, in order to reduce the pressure loss, the total length of the separation column is shortened.

That is, the inner diameter r of the separation column is large and the total length L1 is short. Here, from the viewpoint of (length L1 / inner diameter r), the value L1 / r is preferably 10 or less.

The particle size of the ion exchange resin is preferably small in order to improve the column efficiency (increase the number of theoretical plates). Therefore, the thickness is set to 4 μm or less. In addition, the use of fine particles having a size of 4 μm or less causes a phenomenon that the use limit of the separation column is determined by the linear velocity of the buffer solution.

Looking at the inner diameter of the separation column,
When the conventional standard 30-minute analysis attempts to practical use in the 25-minute analysis, may be the inner diameter ^{(30/25) 2} multiplied by 4.
Since 6 mm × (30/25) ² is 5 mm, the inner diameter is preferably 5 mm or more.

In order to enable the analysis for 15 minutes, the inner diameter may be theoretically set to 6.5 mm in the same manner, but it is experimentally possible to analyze for 15 minutes with the inner diameter of 6 mm. . Further, when the inner diameter is increased and the inner diameter is set to 7 mm or more, the analysis time can be shortened. However, since the sensitivity is lowered, the inner diameter is 5 m from the viewpoint of high-speed analysis.
m or more, and from the viewpoint of sensitivity, 7 mm or less is a practical range. That is, the inner diameter of a practical separation column is 5 mm to 7 mm.
The range of mm is practical.

When the total length of the separation column is shortened and the number of theoretical plates is reduced, the spread outside the column has a large adverse effect on the separation. Considering the contribution to the extension outside the column, it has been experimentally confirmed that the reaction coil is a flow path component that contributes about 80% to the extension outside the column.

Here, the expansion of the sample zone in the reaction coil was determined.
The spread σ in time ^*And when this wide
Σ^*Is set to 4 s or less, it can be ignored for separation.
Conceivable. If this time unit is minute (min),
It may be set to 0.067 min or less.

The spread σ ^{* in} units of time is a function of the inner diameter r of the reaction coil, the length L 2 of the reaction coil, and the column flow rate. Therefore, when the condition of (r ⁴ · L 2) / f for making the spread σ ^* equal to or less than 0.067 min is obtained, the diffusion constant Dm is 1.20 × 10 ⁻⁹ (m
² / s) is determined experimentally,
(R ⁴ · L 2) / f is 1.5 × 10 ⁻⁷ (m ² ·
s) The following condition should be satisfied. Expressing this in units commonly used in liquid chromatography, (r ⁴
・ L2) / f is 2.5 × 10 ⁻³ (mm ⁴ · m / (m
1 / min)).

Also, the spread σ ^{* in} units of time becomes smaller as the flow rate f increases. That is, given r, L
When 2 is given, the influence of the spread σ ^* outside the column can be reduced by increasing the flow rate f.

The inner diameter r of a commonly used reaction coil
The size above 0.25 mm is 0.33 mm. Since the expansion σ ^{* in} units of time is affected by the fourth power of the inner diameter r, the inner diameter r is preferably smaller,
Here, the inner diameter r is 0.25 mm or less.

The longer the reaction coil length L2, the longer the reaction time is, which is preferable in terms of improving the sensitivity. However, the longer the reaction coil length L2, the larger the spread σ ^* becomes. From the point of balance, length L2 is 10m
The following is assumed.

As described above, when the inner diameter r of the reaction coil was set to 0.25 mm or less and the length was set to 10 m or less, the flow rate f (ml / min) of the liquid flowing through the satisfying column was calculated as 2.5 × 10 ^It can be seen that the flow rate f of the liquid flowing through the reaction coil should be set so as to satisfy the condition of ⁻³ (ml / min) or more.

Here, the linear velocity of the liquid flowing through the reaction coil under the above conditions is obtained.
Is 0.25 mm and the flow rate f of the liquid flowing through the column is 2.5
At the time of × 10 ⁻³ (ml / min), the linear velocity is 20 (m
/ Min).

[0232]

According to the present invention, analysis can be performed at a higher speed and with a higher resolution in an amino acid analyzer.

Further, according to the present invention, in the amino acid analyzer, high-resolution analysis can be performed without impairing the separation in consideration of the influence of the extra-column spreading.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the gist of the present invention.

FIG. 2 is a diagram illustrating the spread of a chromatogram.

FIG. 3 is a configuration diagram of an amino acid analyzer according to one embodiment of the present invention.

FIG. 4 is a sectional view of a separation column filled with an ion exchange resin used in the amino acid analyzer according to one embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between a flow rate of a buffer solution flowing through a separation column and a column pressure in the amino acid analyzer according to one embodiment of the present invention.

FIG. 6 is a chromatogram obtained by performing a standard method for 20 minutes using an amino acid analyzer according to one embodiment of the present invention.

FIG. 7 is a chromatogram obtained by a conventional standard method 30-minute analysis.

FIG. 8 is a chromatogram obtained when a standard method is analyzed for 15 minutes using the amino acid analyzer according to one embodiment of the present invention.

FIG. 9 is a chromatogram obtained when a biological fluid method is analyzed for 60 minutes using the amino acid analyzer according to one embodiment of the present invention.

FIG. 10 is a chromatogram obtained by 110-minute analysis of a conventional biological fluid method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st buffer solution 2 ... 2nd buffer solution 3 ... 3rd buffer solution 4 ... 4th buffer solution 5 ... Regeneration solution 6A, 6B, 6C, 6D, 6E ... Electromagnetic valve 7 ... Buffer solution pump 8 ... Ammonia filter column 9 ... Autosampler 10 ... Separation column 11 ... Ninhydrin reagent 12 ... Ninhydrin pump 13 ... Mixer 14 ... Reaction coil 15 ... Photometer 16 ... Data processing device 21 ... Column tube 22 ... Ion exchange resin 23 ... Filter 24 ... Seal 25 ... Column Cap 26: Connection hole 27: Filter space

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G01N 30/60 G01N 30/60 A 30/74 30/74 E 30/84 30/84 A // G01N 21 / 78 21/78 Z 30/50 30/50 30/54 30/54 A (72) Inventor Hiroshi Satake 882 Ma, Hitachinaka-shi, Ibaraki F-term in Hitachi Measuring Instruments Division (Reference) 2G054 AA06 BA10 BB04 BB13 CA21 CB10 EA04 GB10 JA04

Claims (3)

[Claims] Claims: 1. A separation column, a liquid sending means for sending a plurality of buffers to the separation column, and provided in a flow path between the liquid sending means and the separation column;
An amino acid analyzer comprising: a sampler for introducing an analysis sample into a flow channel; a mixer for mixing the analysis sample separated by the separation column with a ninhydrin reagent; and a reaction coil for reacting a solution mixed by the mixer. The column has a ratio (L1 / R) of its length L1 to its inner diameter R of 10 or less, and the inner diameter R is 5 mm or more.
7 mm, and the particle size of the ion exchange resin packed in this separation column is 4 μm.
m or less. 2. The amino acid analyzer according to claim 1, wherein the flow rate of the buffer is 1.0 ml / min or less. 3. The amino acid analyzer according to claim 1, wherein the inner diameter r of the reaction coil is 0.25 mm or less;
The flow rate of the liquid flowing through the reaction coil is 1.0 ml / m
An amino acid analyzer characterized by being at least in.