pH management system for liquid chromatograph and computer-readable recording medium

Abstract

The present invention provides a pH management system for a liquid chromatograph and a computer-readable recording medium. The pH management system for the liquid chromatograph includes: a pH meter that measures the pH value of the mobile phase of the liquid chromatograph; and a warning unit that compares the pH value measured by the pH meter with the set pH value, and gives a warning when it is determined that the pH value measured by the pH meter is different from the set pH value or deviates from the set pH value by more than a specified error rate.

Description

Technical Field

[0001] The present invention relates to a system for managing the pH of a solvent flowing in a liquid chromatograph and a computer-readable recording medium having a program recorded thereon. Background Art

[0002] As an apparatus for analyzing substances contained in a sample, a liquid chromatograph is known. The liquid chromatograph includes a pump unit, an autosampler unit, a column oven unit, a system controller, and the like. In the liquid chromatograph described in Japanese Patent Laid-Open No. 2015-17924, a solvent in which an aqueous solvent and an organic solvent are mixed is supplied as a mobile phase to an analysis flow path. In the analysis flow path, a sample is added to the mobile phase. The sample introduced together with the mobile phase is subjected to component separation in a separation column. The sample that has undergone component separation in the separation column is detected by a detector. A chromatogram is created based on the detection result obtained by the detector.

[0003] In a computer, an analysis method set in the liquid chromatograph is created. In order to obtain good separation of the peaks in the chromatogram, method scouting is performed to rationalize the parameters of the analysis method according to the sample to be analyzed. Examples of the parameters of the analysis method include the injection amount of the sample, the type of separation column, the temperature of the column oven, the detection wavelength of the detector, or the pH (Potential of Hydrogen) value of the mobile phase. Summary of the Invention

[0004] If the pH value of the mobile phase is different, there are cases where the separation of the peaks in the chromatogram is significantly different. Even when the pH value of the mobile phase is rationalized through method scouting, depending on the preparation method of the solvent, the environment, etc., there are cases where the pH of the mobile phase is different from the assumed value.

[0005] An object of the present invention is to reasonably manage the pH of the mobile phase flowing in a liquid chromatograph.

[0006] The pH management system of a liquid chromatograph according to one aspect of the present invention includes: a pH meter that measures the pH value of the mobile phase of the liquid chromatograph; and a warning unit that compares the pH value measured by the pH meter with a set pH value and gives a warning when it is determined that the pH value measured by the pH meter is different from the set pH value or deviates from the set pH value by more than a specified error rate.

[0007] The pH management system of a liquid chromatograph according to another aspect of the present invention includes: a pH meter that measures the pH value of the mobile phase of the liquid chromatograph; and a pH storage unit that stores the pH value measured by the pH meter in association with the analysis result of the liquid chromatograph. Brief Description of the Drawings

[0008] Figure 1 This is the overall diagram of the analysis system of this embodiment.

[0009] Figure 2 This is the structural diagram of the liquid chromatograph of the first embodiment.

[0010] Figure 3 This is a diagram showing an example of the pH gradient set in the analysis method.

[0011] Figure 4 This is the structural diagram of the analysis computer of this embodiment.

[0012] Figure 5 This is the functional block diagram of the analysis computer.

[0013] Figure 6 This is the flowchart showing the process flow of the pH management program.

[0014] Figure 7 This is the structural diagram of the liquid chromatograph of the second embodiment.

[0015] Figure 8 This is the flowchart showing the process flow of the pH management program.

[0016] Figure 9 This is a diagram showing chromatograms based on different pH values.

[0017] Figure 10 This is a diagram showing chromatograms based on different pH values. Specific Embodiments

[0018] Next, the pH management system and program of the liquid chromatograph according to the embodiments of the present invention will be described with reference to the accompanying drawings.

[0019] [1] First Embodiment

[0020] (1) Structure of the Analysis System

[0021] First, the first embodiment of the pH management system and program of the liquid chromatograph of the present invention will be described. In the first embodiment, the pH management system and program acquire the pH value of the mobile phase during the analysis process and determine the abnormality of the pH value. Figure 1 This is the overall diagram of the analysis system of the embodiment. The analysis system includes a liquid chromatograph 1, a communication network 5, and an analysis computer 6. The liquid chromatograph 1 and the analysis computer 6 are connected to the communication network 5 and can communicate with each other.

[0022] The analysis computer 6 performs production processing of an analysis method set in the liquid chromatograph 1. The analysis method produced in the analysis computer 6 is given to the system controller included in the liquid chromatograph 1 via the communication network 5. The liquid chromatograph 1 performs analysis processing under the control of the system controller. The analysis result of the liquid chromatograph 1 is given to the analysis computer 6 via the communication network 5. The analysis computer 6 performs analysis, display processing, etc. based on the analysis result of the liquid chromatograph 1.

[0023] (2) Structure of the liquid chromatograph

[0024] Figure 2 It is a diagram showing the structure of the liquid chromatograph 1 according to the first embodiment of the present invention. As Figure 1 shown, in the present embodiment, the liquid chromatograph 1 includes: a first aqueous solvent supply unit 10, a second aqueous solvent supply unit 20, a mixing unit 41, a sample supply unit 42, a column oven 43, a detector 45, and a pH meter 40. A separation column 44 is housed in the column oven 43.

[0025] The first aqueous solvent supply unit 10 includes a solvent bottle 11 and a liquid feed pump 12. The solvent bottle 11 stores the aqueous solvent. The liquid feed pump 12 presses the aqueous solvent stored in the solvent bottle 11 into the flow path 31. The second aqueous solvent supply unit 20 includes a solvent bottle 21 and a liquid feed pump 22. The solvent bottle 21 stores the aqueous solvent. The liquid feed pump 22 presses the aqueous solvent stored in the solvent bottle 21 into the flow path 32. In the present embodiment, aqueous solvents with different pH values are stored in the solvent bottle 11 and the solvent bottle 21.

[0026] The mixing unit 41 is connected downstream of the flow paths 31 and 32. The aqueous solvents flowing in the flow paths 31 and 32 flow into the mixing unit 41. The mixing unit 41 is a gradient mixer in the present embodiment. The mixing unit 41 generates various solvents (mobile phases) by mixing the aqueous solvent pressed by the liquid feed pump 12 and the aqueous solvent pressed by the liquid feed pump 22 in an arbitrary ratio. As described above, in the present embodiment, aqueous solvents with different pH values are stored in the solvent bottle 11 and the solvent bottle 21. Therefore, in the mixing unit 41, by changing the mixing ratio of the two aqueous solvents, the liquid chromatograph 1 performs a pH gradient.

[0027] The sample supply unit 42 is, for example, an autosampler. The sample supply unit 42 injects a sample to be analyzed into the analysis flow path through which the mobile phase flows, downstream of the mixing unit 41.

[0028] The column oven 43 is arranged downstream of the sample supply unit 42. The column oven 43 houses the separation column 44. The separation column 44 is maintained at the temperature set in the analysis method by the column oven 43. The mobile phase and the sample are supplied to the separation column 44 together. In the separation column 44, the substances contained in the sample are separated.

[0029] The detector 45 is arranged downstream of the column oven 43. The detector 45 detects the sample whose components have been separated in the separation column 44. As the detector 45, for example, an ultraviolet-visible spectrophotometer, a diode array detector, a differential refractive index detector, etc. are used.

[0030] The pH meter 40 is arranged downstream of the detector 45. The pH meter 40 measures the pH value of the mobile phase discharged from the detector 45. As described above, in the present embodiment, the liquid chromatograph 1 performs a pH gradient. Therefore, the pH value measured by the pH meter 40 varies according to the mixing ratio of the two aqueous solvents in the mixing section 41. By arranging the pH meter 40 downstream of the detector 45, the pH value of the mixed aqueous solvent can be obtained based on the setting of the pH gradient. In addition, the pH meter 40 is arranged in the flow path downstream of the detector 45 where the solvent pressure is smaller than that of the flow path upstream of the separation column 44. Thereby, a large pressure can be avoided being applied to the pH meter 40, and thus the pH meter 40 can be protected.

[0031] Figure 3 is an example showing the pH gradient set in the analysis method data AM. In Figure 3 it, the horizontal axis represents time, and the vertical axis represents the pH value of the mobile phase. As Figure 3 shown, in the said pH gradient, the pH value of the mobile phase is set to rise from 4 to 7. Furthermore, the pH value of the mobile phase is set to drop to 4 again after maintaining 7.

[0032] (3) Structure of the analysis computer

[0033] Next, the structure and functions of the analysis computer 6 of the present embodiment will be described. Figure 4 is the structure diagram of the analysis computer 6 of the present embodiment. As Figure 4 shown, the analysis computer 6 includes: a central processing unit (CPU) 61, a random access memory (RAM) 62, a read only memory (ROM) 63, a storage section 64, a communication interface (I / F) 65, a device interface (I / F) 66, a display 67, and an operation section 68. As the analysis computer 6, for example, a personal computer is used.

[0034] The CPU 61 performs overall control of the analysis computer 6. The RAM 62 is used as a work area when the CPU 61 executes a program. Control programs, etc. are stored in the ROM 63. The display 67 displays information such as analysis results. The operation section 68 receives input operations performed by the user. The operation section 68 includes a keyboard and a mouse, etc.

[0035] The storage unit 64 is a storage device such as a hard disk. The pH management program P1, the analysis method data AM, and the analysis data AR are stored in the storage unit 64. The pH management program P1 is a program for managing the pH value of the mobile phase flowing in the liquid chromatograph 1.

[0036] The communication interface 65 is an interface for performing wired or wireless communication with other computers. As Figure 1 shown, the communication interface 65 is connected to the communication network 5. The analysis computer 6 performs data transmission and reception with the liquid chromatograph 1 via the communication interface 65. The device interface 66 is an interface for accessing a storage medium 69 such as a Compact Disk (CD), a Digital Versatile Disc (DVD), or a semiconductor memory.

[0037] Figure 5 is a block diagram showing the functional structure of the analysis computer 6. In Figure 5 it, the control unit 70 is a functional unit implemented by the CPU 61 using the RAM 62 as a work area and simultaneously executing the pH management program P1. The control unit 70 includes: a pH input unit 71, a pH determination unit 72, a warning unit 73, an average value calculation unit 74, and a pH storage unit 75. That is, the pH input unit 71, the pH determination unit 72, the warning unit 73, the average value calculation unit 74, and the pH storage unit 75 are functional units implemented by executing the pH management program P1.

[0038] The pH input unit 71 inputs the pH value of the mobile phase measured by the pH meter 40. The pH input unit 71 obtains the pH value from the liquid chromatograph 1 via the communication network 5. The pH determination unit 72 compares the pH value input by the pH input unit 71 with the pH value set in the analysis method data AM. When it is determined that the pH value measured by the pH meter 40 is different from the pH value set in the analysis method data AM, or the deviation exceeds a specified error rate, the pH determination unit 72 determines that the pH value is abnormal. When it is determined in the pH determination unit 72 that the pH value is abnormal, the warning unit 73 performs a warning display of the pH value on the display 67. The average value calculation unit 74 and the pH storage unit 75 will be described in the second embodiment.

[0039] (4) pH management method

[0040] Next, the pH management method of the present embodiment will be described. Figure 6 is a flowchart showing the pH management method of the present embodiment. First, in step S11, the pH input unit 71 inputs the pH value measured by the pH meter 40. For example, the pH input unit 71 measures time using a timer and executes step S11 at a specified time interval.

[0041] Next, in step S12, the pH determination unit 72 determines whether the pH value input by the pH input unit 71 is different from the pH value set in the analysis method data, or whether it deviates by more than a specified error rate. Specifically, the pH determination unit 72 refers to the analysis method data AM and obtains the pH value set in the analysis method data AM. In the present embodiment, since the liquid chromatograph 1 performs a pH gradient, the pH determination unit 72 obtains the range of the pH value set in the analysis method data AM. Then, the pH determination unit 72 determines whether the pH value input by the pH input unit 71 is within the range obtained by adding the error rate to the range of the pH value set in the analysis method data AM. When the input pH value deviates by more than the range obtained by adding the error rate to the pH value range, the pH determination unit 72 determines that the pH value is abnormal.

[0042] For example, when the pH gradient shown in Figure 3 is set in the analysis method data AM, the pH determination unit 72 obtains the lower limit value 4 to the upper limit value 7 as the range of the pH value. Then, the pH determination unit 72 determines whether the pH value input by the pH input unit 71 is within the range obtained by adding the error rate to the range from the lower limit value 4 to the upper limit value 7. For example, when the error rate is set to α (%), it is determined whether the input pH value is within the range of 4(1 - α / 100) to 7(1 + α / 100). The error rate can be appropriately set by the user. By setting the error rate α to a small value, the pH value can be strictly managed. The error rate α can also be set to "0".

[0043] When it is determined in step S12 that the input pH value is different from the set pH value or deviates by more than the specified error rate, in step S13, the warning unit 73 performs a warning display on the display 67. For example, the warning unit 73 causes the display 67 to display a message indicating that the pH value of the mobile phase in the liquid chromatograph 1 is abnormal. The warning unit 73 can also compare and display the pH value set in the analysis method with the measured pH value. In addition, the warning unit 73 can cause the display 67 to display a selection screen for selecting whether to stop the analysis process of the liquid chromatograph 1. The user operates the operation unit 68 to input an instruction on whether to stop the analysis process. When the warning unit 73 receives an instruction to stop the analysis process, it can send the instruction to the system controller of the liquid chromatograph 1. In response to the instruction, the system controller can stop the analysis process of the liquid chromatograph 1.

[0044] In the above embodiment, since the pH gradient is performed in the liquid chromatograph 1, the measured pH value is compared with the range obtained by adding the error rate to the upper and lower limit values of the pH gradient. When a constant pH value is set as the analysis method, it is only necessary to compare the measured pH value with the range obtained by adding the error rate to the upper and lower of the set pH value.

[0045] Thus, according to the pH management system and program of the liquid chromatograph according to the first embodiment, a warning can be given to the user when the pH value of the mobile phase indicates an abnormal value. Thereby, the user can reasonably manage the pH value of the mobile phase flowing in the liquid chromatograph 1. Thereby, a chromatogram with high resolution according to the analysis conditions rationalized by method exploration can be obtained.

[0046] Figure 9 and Figure 10 is a diagram showing that even for the same sample, the analysis results vary greatly depending on the pH value of the mobile phase. Figure 9 is a chromatogram obtained using the following solvents A and B.

[0047] A: 10 mmol / L sodium citrate (pH 3.1)

[0048] B: Methanol Figure 10 is a chromatogram obtained using the following solvents A and B.

[0049] A: 10 mmol / L ammonium acetate (pH 4.7)

[0050] B: Methanol and acetonitrile (50:50) Figure 9 and Figure 10 Both are gradients in which the concentration of B is set to 90% 5 minutes after the start of solvent supply, and the concentration of B is decreased from 90% to 70% from 5 minutes to 7 minutes. In Figure 10 it can be seen that the peaks are concentrated near 2 minutes after the start of the detection process and the resolution is poor. In contrast, in Figure 9 it can be seen that the resolution of the peaks is good.

[0051] In addition, for example, it is possible to prevent a strongly acidic or strongly basic mobile phase from flowing in the device of the liquid chromatograph 1. In particular, by preventing a strongly acidic or strongly basic mobile phase from flowing in the separation column 44, the separation column 44 can be protected. For example, even when the pH value is correctly adjusted by the user when preparing an aqueous solvent, the pH value may change according to the environment when a certain amount of time has passed from the preparation of the solvent to the analysis process. Even in such a case, the pH value of the mobile phase can be reasonably managed.

[0052] [2] Second Embodiment

[0053] (1) Structure of the Liquid Chromatograph

[0054] Next, a second embodiment of the pH management system and program of the liquid chromatograph of the present invention will be described. Furthermore, the structure and functions of the analysis computer 6 in the second embodiment are the same as those referred to in Figure 4 and Figure 5is the same as the first embodiment described above. In addition, the overall structure of the analysis system is also the same as that Figure 1 shown. In the second embodiment, the pH management system and the program store the pH value of the mobile phase during the analysis process.

[0055] Figure 7 is a diagram showing the structure of the liquid chromatograph 1 according to the second embodiment of the present invention. As Figure 7 shown, in the present embodiment, the liquid chromatograph 1 includes: an aqueous solvent supply unit 100, an organic solvent supply unit 200, a flow path switching valve 30, a pH meter 40, a mixing unit 41, a sample supply unit 42, a column oven 43, and a detector 45.

[0056] The aqueous solvent supply unit 100 includes a plurality (four in this example) of solvent bottles 111 to 114, a flow path switching valve 115, and a liquid delivery pump 120. The solvent bottles 111 to 114 store different types of aqueous solvents respectively. The flow path switching valve 115 selects one or more solvent bottles from the solvent bottles 111 to 114 by switching the flow path between the flow path switching valve 115 and the solvent bottles 111 to 114. The liquid delivery pump 120 pressurizes the aqueous solvent stored in one or more solvent bottles selected by the flow path switching valve 115 and sends it to the flow path 31.

[0057] The organic solvent supply unit 200 includes a plurality (four in this example) of solvent bottles 211 to 214, a flow path switching valve 215, and a liquid delivery pump 220. The solvent bottles 211 to 214 store different types of organic solvents respectively. The flow path switching valve 215 selects one or more solvent bottles from the solvent bottles 211 to 214 by switching the flow path between the flow path switching valve 215 and the solvent bottles 211 to 214. The liquid delivery pump 220 pressurizes the organic solvent stored in one or more solvent bottles selected by the flow path switching valve 215 and sends it to the flow path 32.

[0058] The structures of the mixing unit 41, the sample supply unit 42, the column oven 43, the separation column 44, and the detector 45 are the same as those in the first embodiment. The mixing unit 41 mixes the aqueous solvent pressurized by the liquid delivery pump 120 and the organic solvent pressurized by the liquid delivery pump 220 in an arbitrary ratio.

[0059] Different from the first embodiment, the pH meter 40 is provided in the flow path 33 branched from the flow path 31. The flow path 33 is connected to the flow path switching valve 30 provided in the flow path 31. In the second embodiment, in the mode of measuring the pH value of the mobile phase, the flow path switching valve 30 is switched so that the aqueous solvent pressurized by the liquid delivery pump 120 flows in the flow path 33. On the other hand, in the mode of performing the analysis process, the flow path switching valve 30 is switched so that the aqueous solvent pressurized by the liquid delivery pump 120 flows in the mixing unit 41.

[0060] In the second embodiment, one of the solvent supply units is the organic solvent supply unit 200, so that the pH value of the mobile phase can be obtained in the flow path 33 branched from the flow path 31. That is, the pH value of the aqueous solvent can be obtained at the stage before mixing with the organic solvent in the mixing unit 41. Furthermore, the flow path of the flow path 33 can be made larger than the flow paths of the flow path 31 and the flow path 32. Thereby, a large pressure can be avoided being applied to the pH meter 40 disposed in the flow path 33, and thus the pH meter 40 can be protected.

[0061] (2) pH management method

[0062] Next, the pH management method of the present embodiment will be described. Figure 8 It is a flowchart showing the pH management method of the present embodiment. First, in step S21, the pH input unit 71 inputs the pH value measured by the pH meter 40 and stores the input pH value in the storage unit 64.

[0063] Next, in step S22, the pH input unit 71 determines whether a predetermined measurement time has elapsed. If the predetermined measurement time has not elapsed, the process returns to step S21, and the pH input unit 71 inputs the newly measured pH value by the pH meter 40 and stores the input pH value in the storage unit 64. The pH input unit 71 repeats the process of step S21 until the predetermined measurement time elapses. Thereby, the pH values within the predetermined measurement time are accumulated in the storage unit 64.

[0064] When it is determined in step S22 that the predetermined measurement time has elapsed, in step S23, the average value calculation unit 74 acquires a plurality of pH values within the predetermined measurement time stored in the storage unit 64 and calculates the average value.

[0065] Next, in step S24, the pH storage unit 75 stores the average value of the calculated pH values in the storage unit 64 in association with the analysis result. For example, when performing an analysis process related to a certain analysis method, a predetermined time after the start of the analysis process is set as the pH measurement mode. In the pH measurement mode, by controlling the flow path switching valve 30, all of the aqueous solvent flowing into the flow path switching valve 30 is transported to the flow path 33. Thereby, the pH value of the mobile phase is measured by the pH meter 40, and the Figure 8 process is executed. For example, the time from 1 minute to 2 minutes after the start of the analysis process can be set as the pH measurement mode. When the average value of the pH value is calculated and the pH value measurement mode is completed, the process transfers to the analysis mode. In the analysis mode, by controlling the flow path switching valve 30, all of the aqueous solvent flowing into the flow path switching valve 30 is transported to the mixing unit 41. Thereby, the analysis process is executed. The pH storage unit 75 can store the average value of the pH values calculated in the pH measurement mode and the analysis result obtained in the immediately following analysis mode in the storage unit 64 as analysis data AR in association with each other.

[0066] Alternatively, an analysis method may be created as a pH measurement mode. In this case, two analysis methods with the same analysis parameters are created in the analysis method data AM. One of the two analysis methods is executed as the pH measurement mode, and the other is executed as the analysis mode. Then, by managing these two analysis methods as a pair, the average value of the pH values obtained in the pH measurement mode can be saved as analysis data AR in association with the analysis results obtained in the analysis mode.

[0067] Thus, according to the pH management system and program of the liquid chromatograph according to the second embodiment, the pH value of the mobile phase during the execution of the analysis process can be saved in association with the analysis results. Thereby, the pH value of the mobile phase flowing in the liquid chromatograph 1 can be reasonably managed.

[0068] In method exploration, after the user sets the type of the mobile phase, the type of the column, etc., the composition ratio of the mobile phase is set. The user makes various changes to the composition ratio of the mobile phase to create multiple analysis methods. That is, multiple analysis methods with different pH values of the mobile phase are created. The liquid chromatograph 1 executes the analysis process according to these multiple analysis methods with different pH values of the mobile phase. Thus, even in the case of performing a series of analysis processes with different pH values of the mobile phase, according to the pH management system and program of the present embodiment, the user can refer to the results of the series of analysis processes and the actual pH value of the mobile phase during the analysis process. Thereby, the user can compare and study the analysis results based on different pH values.

[0069] [3] Correspondence between the components of the technical solution and the components of the embodiment

[0070] Hereinafter, examples of the correspondence between the components of the technical solution and the components of the embodiment will be described, but the present invention is not limited to the following examples. In the above embodiment, the flow path 31 is an example of the first flow path, and the flow path 32 is an example of the second flow path. In addition, in the above embodiment, the analysis computer 6 is an example of the computer.

[0071] As the components of the technical solution, various components having the structures or functions described in the technical solution may also be used.

[0072] [4] Other embodiments

[0073] In the first embodiment, the pH meter 40 is arranged downstream of the detector 45. As a modification, the pH meter 40 can be arranged upstream of the detector 45. For example, the pH meter 40 can also be arranged in the flow path between the mixing section 41 and the column oven 43, or can be arranged in the flow path between the column oven 43 and the detector 45. However, when the pH meter 40 is arranged upstream of the column oven 43, the pressure of the solvent flowing in the flow path becomes high, so it is desirable to use a device with strong pressure resistance as the pH meter 40.

[0074] In the first embodiment, in Figure 2 the liquid chromatograph 1 shown, the pH value of the mobile phase is obtained by the pH meter 40 arranged downstream of the detector 45, and an alarm is notified to the user when it is determined that the pH value is abnormal. As another embodiment, in Figure 7 the liquid chromatograph 1 of the second embodiment shown, the pH value of the mobile phase can also be obtained by the pH meter 40 arranged in the flow path 33, and an alarm is notified to the user when it is determined that the pH value is abnormal.

[0075] In the second embodiment, in Figure 7 the liquid chromatograph 1 shown, the pH value of the mobile phase during the execution of the analysis process is saved by the pH meter 40 arranged in the flow path 33. As another embodiment, in Figure 2 the liquid chromatograph 1 of the first embodiment shown, the pH value of the mobile phase during the execution of the analysis process can also be saved by the pH meter 40 arranged downstream of the detector 45.

[0076] In the above embodiment, the case where the pH management program P1 is saved in the storage unit 64 is taken as an example for explanation. As another embodiment, the pH management program P1 can also be saved in the storage medium 69 and provided. The CPU 61 of the analysis computer 6 can also access the storage medium 69 via the device interface 66, and save the pH management program P1 saved in the storage medium 69 in the storage unit 64 or the ROM 63. Alternatively, the CPU 61 can also access the storage medium 69 via the device interface 66 and execute the pH management program P1 saved in the storage medium 69.

[0077] In the first embodiment, the case where the warning unit 73 gives a warning by comparing the pH value measured by the pH meter 40 with the pH value set in the analysis method data AM has been described. As another embodiment, the pH value measured by the pH meter 40 may be compared with the pH value set for each separation column. For example, regarding a plurality of separation columns, information associating each identification information with the range of the pH value of the mobile phase that can be used is stored in the storage unit 64. When the pH value measured by the pH meter 40 exceeds the pH value of the mobile phase that can be used for the separation column, the warning unit 73 may give a warning.

[0078] In the second embodiment, the average value of the pH values obtained in the pH measurement mode is saved in association with the analysis result obtained in the analysis mode. As another embodiment, the median value, maximum value, or minimum value of the pH values obtained in the pH measurement mode may be saved in association with the analysis result. Alternatively, all the pH values measured within a specified time or a graph of the pH values may be saved in association with the analysis result.

[0079] [5] Form

[0080] Those skilled in the art will understand that the above-described multiple exemplary embodiments are specific examples of the following forms.

[0081] (First item)

[0082] The pH management system of a liquid chromatograph according to one form of the present invention includes:

[0083] a pH meter that measures the pH value of the mobile phase of the liquid chromatograph; and

[0084] a warning unit that compares the pH value measured by the pH meter with the set pH value and gives a warning when it is determined that the pH value measured by the pH meter is different from the set pH value or deviates from the set pH value by more than a specified error rate.

[0085] The pH of the mobile phase flowing in the liquid chromatograph can be reasonably managed.

[0086] (Second item)

[0087] According to the pH management system of the liquid chromatograph described in the first item, it may also be:

[0088] The set pH value is set in the analysis method data of the liquid chromatograph.

[0089] The pH of the mobile phase can be reasonably managed based on the pH value set in the analysis method data.

[0090] (Third item)

[0091] The pH management system of the liquid chromatography instrument according to the second item may also be:

[0092] The analysis method data includes the setting of the pH gradient,

[0093] When it is determined that the pH value measured by the pH meter deviates from the upper limit value and the lower limit value of the pH range of the pH gradient by more than a specified error rate, the warning unit gives a warning.

[0094] When performing the pH gradient, the pH of the mobile phase can be reasonably managed.

[0095] (Fourth item)

[0096] The pH management system of the liquid chromatography instrument according to any one of the first to third items, wherein it may also be:

[0097] The pH meter is provided downstream of the detector included in the liquid chromatography instrument.

[0098] Downstream of the detector, the pressure of the solvent becomes low, so a large pressure can be prevented from being applied to the pH meter.

[0099] (Fifth item)

[0100] Another form of the pH management system of the liquid chromatography instrument of the present invention includes:

[0101] A pH meter that measures the pH value of the mobile phase of the liquid chromatography instrument; and

[0102] A pH storage unit that stores the pH value measured by the pH meter in association with the analysis result of the liquid chromatography instrument.

[0103] The pH of the mobile phase flowing in the liquid chromatography instrument can be reasonably managed.

[0104] (Sixth item)

[0105] The pH management system of the liquid chromatography instrument according to the fifth item may also be:

[0106] It further includes an average value calculation unit that calculates the average value of the pH values measured by the pH meter,

[0107] The pH storage unit stores the average value of the pH values calculated by the average value calculation unit in association with the analysis result of the liquid chromatography instrument.

[0108] Using the average value of the pH values measured by the pH meter, the pH of the mobile phase flowing in the liquid chromatography instrument can be reasonably managed.

[0109] (Seventh item)

[0110] The pH management system of the liquid chromatography instrument according to item 5 or 6 may also be:

[0111] The liquid chromatography instrument includes:

[0112] A first flow path for supplying an aqueous solvent;

[0113] A second flow path for supplying an organic solvent; and

[0114] A mixing section for mixing the aqueous solvent supplied via the first flow path and the organic solvent supplied via the second flow path,

[0115] The pH meter measures the pH value of the aqueous solvent flowing in the first flow path.

[0116] It is possible to obtain the pH value of the aqueous solvent before mixing with the organic solvent. Thus, it is possible to preserve the pH value that does not affect the analysis result.

[0117] (Item 8)

[0118] The pH management system of the liquid chromatography instrument according to any one of items 5 to 7 may also be:

[0119] It further includes a storage section that stores analysis method data,

[0120] The analysis method data includes an analysis method for measuring the pH value in the pH meter.

[0121] By creating an analysis method dedicated to pH measurement, it is possible to obtain the pH value without affecting the analysis process.

[0122] (Item 9)

[0123] In a computer-readable recording medium recording the pH management program of the liquid chromatography instrument according to another aspect of the present invention,

[0124] The pH management program of the liquid chromatography instrument causes the computer to execute the following processing:

[0125] Input the pH value of the mobile phase of the liquid chromatography instrument measured by the pH meter;

[0126] Determine whether the pH value measured in the pH meter is different from the set pH value, or whether it deviates from the set pH value by more than a specified error rate; and

[0127] In the case where it is determined that the measured pH value is different from the set pH value, or deviates from the set pH value by more than a specified error rate, a warning is prompted.

[0128] (Item 10)

[0129] In another form of the present invention, in a computer-readable recording medium recording a pH management program for a liquid chromatograph,

[0130] the pH management program of the liquid chromatograph causes the computer to perform the following processing:

[0131] input the pH value of the mobile phase of the liquid chromatograph measured by a pH meter, and

[0132] save the input pH value in association with the analysis result of the liquid chromatograph.

Claims

1. A pH management system for a liquid chromatography instrument, comprising: A liquid chromatography instrument, comprising: A first flow path for supplying an aqueous solvent; A second flow path for supplying an organic solvent; A mixing section for mixing the aqueous solvent supplied via the first flow path with the organic solvent supplied via the second flow path; A branch flow path, which is a flow path branched from the first flow path; and A flow path switching valve connected between the first flow path and the branch flow path, A pH meter that measures the pH value of the mobile phase of the liquid chromatography instrument whenever an analysis based on the liquid chromatography instrument is performed. The pH meter is provided on the branch flow path, wherein, In the mode of measuring the pH value of the mobile phase, by controlling the flow path switching valve, the aqueous solvent flowing into the flow path switching valve from the first flow path is transported to the branch flow path, so that the pH meter measures the pH value of the aqueous solvent. In the mode of performing analysis processing related to an analysis method using the liquid chromatography instrument, by controlling the flow path switching valve, the aqueous solvent flowing into the flow path switching valve from the first flow path is transported to the mixing section; and A pH storage section that stores the pH value measured by the pH meter in the mode of measuring the pH value of the mobile phase whenever an analysis based on the liquid chromatography instrument is performed, in association with the analysis result in the mode of performing analysis processing related to the analysis method using the liquid chromatography instrument.

2. The pH management system for a liquid chromatography instrument according to claim 1, further comprising an average value calculation section that calculates the average value of the pH values measured by the pH meter, The pH storage section stores the average value of the pH values calculated by the average value calculation section in association with the analysis result of the liquid chromatography instrument.

3. The pH management system for a liquid chromatography instrument according to claim 1 or 2, further comprising a storage section that stores analysis method data, The analysis method data includes an analysis method for measuring the pH value in the pH meter.

4. A computer-readable recording medium that records a pH management program for a liquid chromatograph, wherein, The pH management program for the liquid chromatography instrument causes a computer of the pH management system for the liquid chromatography instrument according to any one of claims 1 to 3 to perform the following processing: Whenever an analysis based on the liquid chromatography is performed, input the pH value of the mobile phase of the liquid chromatography instrument measured by the pH meter; And Store the pH value measured and input by the pH meter in the mode of measuring the pH value of the mobile phase whenever an analysis based on the liquid chromatography instrument is performed, in association with the analysis result in the mode of performing analysis processing related to the analysis method using the liquid chromatography instrument.

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