SEPARATION CHROMATOGRAPHY SUPPORTING DEVICE, SEPARATION CHROMATOGRAPHY APPARATUS, AND SEPARATION CHROMATOGRAPHY METHOD
20240264133 ยท 2024-08-08
Inventors
Cpc classification
G01N30/90
PHYSICS
B01D15/166
PERFORMING OPERATIONS; TRANSPORTING
International classification
B01D15/16
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Provided is a separation chromatography supporting device capable of predicting, using a result of thin-layer chromatography or column chromatography, a result of liquid chromatography for a wide range of compounds with high accuracy and setting an optimum separation condition. The separation chromatography supporting device includes a calculation formula acquisition unit, and provides information related to separation in column chromatography based on an actually measured value of an Rf value when a mixed solvent having a mixing ratio B of two specific types of solvents measured by thin-layer chromatography or liquid chromatography is used. The calculation formula acquisition unit acquires a.sub.1 in a relational formula of
Claims
1. A separation chromatography supporting device comprising: a calculation formula acquisition unit, wherein the separation chromatography supporting device provides information related to separation in column chromatography based on an actually measured value of an Rf value when a mixed solvent having a mixing ratio B of two specific types of solvents measured by thin-layer chromatography or liquid chromatography is used, and the calculation formula acquisition unit acquires a.sub.1 in a relational formula of
2. The separation chromatography supporting device according to claim 1, further comprising: a calculation formula acquisition unit configured to actually measure a relationship between Rf values of plural types of compounds and a mixing ratio B of a solvent for a combination of two specific types of solvents, the calculation formula acquisition unit being obtained based on data obtained in the measurement.
3. A separation chromatography apparatus comprising: the separation chromatography supporting device according to claim 1 or 2.
4. A separation chromatography method comprising: a step (1) of performing thin-layer chromatography on a compound to be separated in a mixed solvent having a mixing ratio B of two specific types of solvents; a step (2) of inputting an Rf value and the mixing ratio B obtained in step (1) into the separation chromatography supporting device according to claim 1; a step (3) of acquiring, based on data input in step (2), a.sub.1 or a.sub.2 in a relational formula of
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
[0018] The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the present invention taken with the accompanying drawing figures, in which:
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] A separation chromatography supporting device according to the present invention can predict a behavior when separation chromatography is performed on a compound to be separated based on a result of TLC, and can find an optimum chromatography condition and accurately predict a result of the chromatography before an operation.
[0029] In such a separation chromatography supporting device, a method of clarifying a relationship between a solvent mixing ratio and an Rf value based on the result of TLC and thereby predicting the result of chromatography is adopted. Here, in PTL 1, prediction is performed on a premise that the relationship between the mixing ratio of each component in an eluent and mobility Rf of a sample is a proportional relationship, and that a change rate of the mobility Rf of the sample with respect to the mixing ratio of the component in the eluent is the same even though a type of the sample is changed.
[0030] In PTL 2, prediction is performed based on a relational formula different from that in PTL 1, and is performed on a premise that a change rate in the relational formula is the same even though a type of a sample is changed.
[0031] PTL 3 discloses that TLC is performed on at least two points in which solvent mixing ratios are different. However, it is preferable that accurate prediction can be performed by TLC on one point.
[0032] The premise that a change rate of the mobility Rf of the sample with respect to the mixing ratio of each component in the eluent is the same even though a type of the sample is changed in PTLs 1 and 2 is not absolutely correct, and is considered as an approximation method. That is, although a certain degree of accurate prediction can be performed based on such a premise, the relationship between the mobility Rf of the sample and the mixing ratio of each component in the eluent actually causes a certain degree of change due to a change in the type of the sample.
[0033] Therefore, when it is necessary to perform more accurate analysis, it is required to perform prediction with higher accuracy than that described in PTLs 1 and 2. In order to cope with such a case, an object of the present invention is to provide a method for predicting a result of chromatography with higher accuracy.
[0034] In order to describe the method according to the present invention,
[0035] On the other hand, it can be seen that such a difference is large between a compound having a large Rf even though a nonpolar solvent is used and a compound having a small Rf unless a polar solvent is used, that is, a compound presenting as a straight line in a left direction on the graph in
[0036] The present invention is completed based on such a viewpoint. That is, when the relationship between the mixing ratio of each component in the eluent and the mobility Rf is expressed as
[0038] Further, the same prediction can also be performed for a.sub.2 in a relational formula of
[0040] Hereinafter, an example of a method for calculating a.sub.1 and a.sub.2 will be described in detail. The method for calculating a.sub.1 and a.sub.2 in the present invention is not limited to the method exemplified below. A case according to Formula (1) and a case according to Formula (2) will be described in detail below.
[0041] In the present description, B is the solvent mixing ratio, and is, for example, a value indicating a ratio of any one of solvents when liquid chromatography is performed in a mixed system including two types of solvents of X and Y. As any one of a molar fraction (mol %), a volume ratio (vol %), a weight ratio (wt %), and the like, the mixing ratio shows a certain correlation, and thus any one among these can be used. In the following example, experimental results with the molar fraction (mol %) serving as a reference are shown.
(Approximation According to Formula (1))
[0042] First, data obtained by measuring Rf values of various compounds in a specific mixed solvent at various solvent mixing ratios is acquired. Rf can be obtained for various B in the same compound. The actually measured data is approximated as a linear expression. That is, for actually measured values of TLC, the relational formula of Rf=a.sub.1B+b.sub.1 is created for each compound. Then, such a measurement and formula creation are performed on many types of compounds.
[0043] As is clear from
[0044] Further, all the calculation formulas corresponding to positions on the coordinates may be created at coordinates of Rf/B and stored, so that a calculation formula may be acquired by calling the calculation formula as required.
[0045] The method for calculating a.sub.1 based on the results as shown in
[0046] As is clear from
[0047] Therefore, for example, a relationship between each slope a.sub.1 and B can be expressed when the Rf value is fixed. This is shown in
[0048] That is, based on results in
[0049] Further, as can be seen from
[0050] Since d, g, and h are constants determined by a type of a mixed solvent, a.sub.1 can be calculated when B and Rf are measured.
[0051] By using the general formula (4) created in this way, it is possible to calculate a.sub.1 with respect to B when a specific Rf value is used. Further, for many types of Rf values, a.sub.1 may be calculated for any combination of Rf and B by preparing such a formula, and a.sub.1 may be calculated based on actually measured values of Rf and B according to the general formula (4-1) described above.
[0052] Based on actually measured values for various compounds, a calculation formula for calculating a.sub.1, such as the general formulas (4) and (4-1) as described above, is created in advance, and a.sub.1 can be calculated by performing the above calculation by a calculation formula acquisition unit of the separation chromatography supporting device according to the present invention.
[0053] For example, TLC is performed on a compound to be separated at a specific solvent mixing ratio B, an Rf value is measured, and a.sub.1 can be calculated according to the general formulas (4) and (4-1) based on the relationship between B and Rf. Further, the general formula (1) described above can also be created. The separation chromatography supporting device according to the present invention includes the calculation formula acquisition unit that creates the general formula (1).
[0054] By performing such processing, it is possible to obtain, for any point on a coordinate axis, the general formula (1) closer to actual results of the column chromatography than that in the related art. Further, in such processing, it is also not necessary to perform TLC a plurality of times.
[0055] In addition, for any point on the coordinate axis, the above formula (1) may be created according to the calculation formula described above or another method, all formulas may be stored in the calculation formula acquisition unit, and a calculation formula may be acquired by calling the calculation formula (1) corresponding to the input Rf value and B.
[0056] When separation column chromatography is performed on a sample containing a plurality of types of compounds, the formula (1) can be created for each of the plurality of compounds to be separated by the calculation formula acquisition unit described above. Based on the plurality of formulas (1) obtained in this way, results of column chromatography as described in detail below can be predicted.
(Approximation According to Formula (2))
[0057] When approximation is performed based on Formula (2), it is possible to essentially perform a study using the same method as that in Formula (1) described above. The approximation is basically the same as that disclosed in PTL 2. In the present invention, when a result of chromatography is predicted based on the Formula (2), a value of a.sub.2 is calculated based on a result of TLC rather than performing approximation on a premise that the slope a.sub.2 is normally constant.
[0058] Therefore, mathematical processing similar to that performed on the general formula (1) described above is performed, and a calculation formula for calculating the value of a.sub.2 corresponding to a specific Rf value is acquired using the same method, whereby the general formula (2) close to an actual situation can be created.
[0059] In the above aspect of the present invention, a retention force k is defined by the following formula (3)
[0060] Here, t.sub.0 is time required for an elution solvent to pass through a specific column and is a value specific to the column determined by a size, a shape, and the like of the column, and t.sub.R is an elution time required for a sample to be separated to pass through a specific column. Since to is a constant specific to the column, the elution time t.sub.R when the specific column is used can be obtained by obtaining k.
[0061] The retention force k and the solvent ratio B have a relationship expressed by the following formula (2)
[0062] In order to perform analysis based on the general formula (2), it is necessary to clarify a relationship between Rf, which is the result of TLC, and k described above. This point will be described in detail later. Generally, it is known that a relationship of t.sub.R=t.sub.0/Rf is established between Rf of thin-layer chromatography and t.sub.0 and t.sub.R of liquid chromatography. Therefore, when Rf is measured, a relationship between t.sub.0 and t.sub.R is clear, and k in the general formula described above is obtained by substituting the relationship between t.sub.0 and t.sub.R into the general formula (3).
[0063] Specifically, k=(1/Rf)?1 is obtained. By performing the same processing as that performed on Formula (1) described above using this formula, a relational formula between a.sub.2 and B is created for each k. Then, these relational formulas are stored in the calculation formula acquisition unit. It is possible to obtain an appropriate Formula (2) based on the result of TLC using the same method as that in Formula (1) described above except that an approximate expression is different.
(Correction for Difference Between TLC and Liquid Chromatography)
[0064] The general formulas (1) and (2) obtained by the above TLC may not completely coincide with a relational formula in liquid chromatography.
[0065] Therefore, a correction item for correcting such a deviation may be further added to the general formulas (1) and (2) described above. Such a correction item is not specifically limited, and the general formulas (1) and (2) can be corrected by acquiring data on separation by TLC and column chromatography and analyzing the data.
[0066] Further, when the general formulas (1) and (2) with respect to any combination of B and Rf as described above are stored, a calculation formula in consideration of the above deviation may be created in these calculation formulas and stored.
(Type of Solvent in Mixed Solvent)
[0067] In separation column chromatography, when separation is performed with a mixed solvent using a plurality of types of solvents, several types of combinations of the solvents are conceivable. The relationship between B and Rf as described above is specific to a type of solvent to be used, and when the type of solvent is changed, a formula to be used when the general formulas (1) and (2) are calculated is also different.
[0068] Therefore, in the separation chromatography supporting device according to the present invention, a plurality of types of data for a combination of a plurality of types of solvents may be stored as the calculation formula acquisition unit for a.sub.1 and a.sub.2 as described above. In this case, an analysis based on a result of TLC as described above can be performed on each combination of solvents, a general formula can be created and stored in the calculation formula acquisition unit. In this way, the number of types of operations that can be supported by the separation chromatography supporting device according to the present invention is greatly increased, and utility is improved.
[0069] Such a combination of solvents is not particularly limited, and a combination of a nonpolar solvent and a polar solvent is preferable. More preferable examples thereof include hexane/ethyl acetate, hexane/chloroform, chloroform/methanol, ethyl acetate/methanol, hexane/dichloromethane, and dichloromethane/methanol. Depending on properties of a compound to be separated, an appropriate combination of solvents can be selected from these combinations and used.
(Gradient)
[0070] A gradient pattern refers to a change pattern in which a solvent mixing ratio changes with time and a gradient is performed when liquid chromatography is performed. For example, this means what is shown in
[0071] When the relational formula of the general formula (1) or the general formula (2) is clear, it is possible to predict an elution state when the gradient is performed using a known method as described in, for example, PTLs 2 and 3. Accordingly, it is possible to predict an elution curve when separation column chromatography is actually performed.
[0072] Accordingly, since an elution time of a sample can be calculated based on a mixing ratio of an eluent or a gradient pattern of the mixing ratio of the eluent, it can be determined in advance whether separation by liquid chromatography can be achieved. Thus, based on the calculation result, it is possible to select an optimum mixing ratio of the eluent or an optimum gradient pattern of the mixing ratio of the eluent that enables sufficient separation.
(Configuration of Invention)
[0073] The present invention provides a separation chromatography supporting device, and provides a calculation formula useful for performing separation chromatography by the calculation formula acquisition unit described above. When such a separation chromatography supporting device is actually applied to liquid chromatography, preferable aspects of the device include a liquid chromatography control device, a method for performing liquid chromatography, and a liquid chromatography control program.
[0074] Such a separation chromatography supporting device according to the present invention preferably uses a computer. A computer that stores calculation formulas or programs for performing the above processing is preferably used. Further, a computer that stores programs for performing such processing on a server using a network, accesses to such programs from a client, and performs processing may be used.
[0075] Hereinafter, each unit will be described in detail.
(Actually Measured Value Storage Unit)
[0076] An actually measured value storage unit is a unit that stores results of thin-layer chromatography.
[0077]
[0078] Further, the eluent 4 to be used is a solvent in the same solvent system as that used in the liquid chromatography, and uses a mixed solvent.
[0079] In TLC, first, as shown in
[0080] In this case, an operator may read an Rf value from the thin-layer plate after measurement and input the value as a numerical value, or a thin-layer chromatography plate may be placed at a predetermined position of the device and the Rf value may be automatically read based on image analysis. In spot analysis, it is possible to adopt a method for reading a spot position by emitting detection light such as ultraviolet rays as necessary and utilizing light emission generated by the detection light.
[0081] The actually measured value storage unit is a unit that stores the Rf value obtained by the thin-layer chromatography in association with the solvent mixing ratio B. The values stored in this way are used in the calculation formula acquisition unit below.
(Calculation Formula Acquisition Unit)
[0082] The calculation formula acquisition unit in the present invention is a unit that creates the general formula (1) for a specific component with respect to a specific solvent system based on the result of the above thin-layer chromatography. The calculation formula is described above in detail.
(Liquid Chromatography Result Prediction Unit)
[0083] When the general formula (1) or the general formula (2) is determined for all samples that are required to be separated, a mixing ratio of an eluent and an elution time corresponding to a column to be used can be predicted. Based on this, an operator can easily estimate a favorable solvent mixing ratio.
[0084] Further, when a specific liquid chromatography condition (for example, a sample amount) is input, an elution time corresponding to the liquid chromatography condition can also be presented. Further, it is also possible to display a separation degree Rs or an expected elution curve. The operator can easily determine quality of a plurality of types of liquid chromatography conditions by viewing these pieces of information. Accordingly, it is possible to easily select an optimum liquid chromatography condition (solvent mixing ratio, column to be used, and the like) before an experiment.
[0085] A result of liquid chromatography can be predicted by a normal computer, and results thereof can be displayed on a general display device represented by various displays.
[0086] The elution time in the liquid chromatography can be calculated according to methods described in the related art as described in PTLs 2 to 4. By combining the method according to the present invention and the methods described in the patent literatures, predictions can be performed more accurately and a preferable method is obtained.
[0087] As presentations of the liquid chromatography result prediction, the elution time and the separation degree may be shown as specific numerical values in an image, and the elution curve may be displayed. By comparing these values corresponding to several measurement conditions, the operator can learn an optimum liquid chromatography method.
[0088] When the chromatography conditions are determined, column selection is also an important factor. As described above, a sample load amount is also an important factor in the column selection. That is, when the amount of the sample to be separated is large, a larger column is required. Information necessary for such a purpose may be displayed in an image.
(Liquid Chromatography Condition Determination Unit)
[0089] In the present invention, the operator evaluates the liquid chromatography conditions created by himself or herself or recommended by a device while using the liquid chromatography result prediction unit, and finally determines the liquid chromatography conditions.
(Mixing Ratio Control Unit)
[0090] In the present invention, liquid chromatography may be performed based on determination performed by a liquid chromatography condition determination unit. A mixing ratio control unit is a unit that outputs, based on a liquid chromatography condition selected by the operator based on the liquid chromatography condition determination unit, a control signal for controlling a mixing ratio of an eluent to be sent to a column or a gradient pattern of the mixing ratio of the eluent. As the mixing ratio control unit, a known unit can be used.
(Liquid Chromatography Control Device)
[0091] Hereinafter, an example of an aspect of the liquid chromatography control device according to the present invention will be described in more detail with reference to the drawings. The present invention is not limited to contents described in the following drawings. The present invention may relate to a liquid chromatography apparatus including necessary elements and a control device that controls liquid chromatography by the above units using a computer that controls the liquid chromatography apparatus. An example of an aspect in which the above method is used when an actual apparatus is operated will be described below in detail.
[0092] In the present invention, a gradient condition for general-purpose liquid chromatography may be stored as a library, and the computer may automatically select a gradient pattern of a recommended mixing ratio of an eluent or a recommended gradient pattern of the mixing ratio of the eluent from the library based on a result of the general formulas (1) and (2) for each component, and the gradient pattern may be recommended to an operator. The operator may determine a liquid chromatography condition in a manner of approving a recommended condition.
[0093] When the chromatography condition is determined, column selection is also an important factor. Therefore, for t.sub.0, it is also preferable that to corresponding to each column used in the liquid chromatography is stored in the liquid chromatography result prediction unit, and that a corresponding value of t.sub.0 is called when the operator selects a column. In addition, as necessary, a function of manually inputting t.sub.0 may be provided.
[0094] In the present invention, the operator evaluates the liquid chromatography condition created by himself or herself or recommended by a device while using the liquid chromatography result prediction unit, and finally determines the liquid chromatography condition.
(Mixing Ratio Control Unit)
[0095] In the present invention, liquid chromatography is performed based on the determination by the liquid chromatography condition determination unit described above. A mixing ratio control unit is a unit that outputs, based on a liquid chromatography condition selected by the operator based on the liquid chromatography condition determination unit, a control signal for controlling a mixing ratio of an eluent to be sent to a column or a gradient pattern of the mixing ratio of the eluent. As a mixing ratio control unit, a known unit can be use, and for example, a unit as disclosed in PTL 1 can be used.
(Liquid Chromatography Control Device)
[0096] Hereinafter, an example of an aspect of the liquid chromatography control device according to the present invention will be described in more detail with reference to the drawings. The present invention is not limited to contents described in the following drawings. The present invention relates to a liquid chromatography apparatus including necessary elements and a control device that controls liquid chromatography by the above units using a computer that controls the liquid chromatography apparatus. An example of an aspect in which the above method is used when an actual device is operated will be described below in detail.
[0097]
[0098] The solvent A is stored in the container 12, and the solvent B is stored in the container 13. In addition, a solvent to be used is not limited to two types, and the number of types thereof may increase depending on a use state and a purpose. In general, a combination of nonpolar molecules and polar molecules is used for the solvent A and the solvent B.
[0099] The pump 16 pumps up the solvent A and the solvent B via the container 15 and the solenoid valve 14 in the path of the liquid chromatography device 11. The solenoid valve 14 selects a solvent to be pumped up from the solvent A and the solvent B according to a control signal from the liquid chromatography control device 21. A mixing ratio of the solvents A and B in the mixer 15 is determined according to time for selecting each solvent by the solenoid valve 14. In the mixer 15, the pumped-up solvents A and B are temporarily stored and used as the mixed solvent 10. The mixed solvent 10 has a calculated mixing ratio as described later.
[0100] The injector 17 contains the sample 3, and the sample 3 is sent out by the mixed solvent 10 passing through the injector 17. In addition, the number of injectors 17 is not limited to one, and it is also possible to continuously operate a plurality of samples by arranging a plurality of injectors side by side so as to be selectable in path selection.
[0101] The column 18 is filled with a stationary phase, and liquid chromatography is performed by the mixed solvent 10 passing through the stationary phase. Silica gel for forming the silica gel thin-layer plate 2 as shown in
[0102] The detector 19 detects a result of the liquid chromatography performed in the column 18. The fraction collector 20 includes a plurality of test tubes, and, based on an analysis result of the detector 19, components contained in the sample 3 are separated into the test tubes respectively.
[0103] The liquid chromatography control device according to the present invention is a device for controlling the liquid chromatography as shown in
[0104] Accordingly, the liquid chromatography is favorably performed by performing calculation as described above and controlling the liquid chromatography.
Example
[0105] Hereinafter, the present invention will be described in more detail with reference to an example.
(Method for Calculating a.SUB.1 .Based on TLC Measurement)
[0106] A plurality of types of mixed solvents containing B % by weight of X with respect to a mixed weight of X and Y were prepared as two specific types of solvents, then TLC was performed on 13 types of compounds with respect to the plurality of types of mixed solvents having different ratios of B, and a relational formula of
[0107] was clarified for each of the compounds. The calculated general formulas (1) for the 13 types of compounds were shown on a graph in
[0108] Further, based on
[0109] For each of the Rf values obtained in this manner, the relational formula indicating the relationship between a.sub.1 and log B was created using the method described above and stored in a computer. Accordingly, when Rf and B were input, a corresponding general formula (1) was called.
[0110] A separation chromatography experiment was performed using a separation chromatography supporting device prepared in this manner.
[0111] In the experiment, a test sample obtained by mixing three types of compounds was used. TLC measurement was performed on one point using a specific mixed solvent B. Then, based on this, the general formula (1) was created for the three types of compounds, whereby an elution curve was predicted for several recommended gradient patterns. An optimum result was selected from these results, and separation chromatography was performed accordingly. In order to perform separation chromatography, the device as shown in
[0112] The results were shown in
[0113] As described in PTL 1, the same experiment was performed based on the result of TLC and based on a fixed value of a.sub.1. The results are shown in
[0114] When these results are compared, there is a difference in the expected value of the elution time. When actual separation column chromatography was performed, a prediction result based on the separation chromatography supporting device according to the present invention was close to a result of the separation column chromatography. Therefore, the separation chromatography supporting device according to the present invention has more excellent performance than devices in the related art.
[0115] The separation chromatography supporting device according to the present invention can be suitably used in the separation chromatography in studies of a chemical field.
PARTS LIST
[0116] 1 TLC device [0117] 2 silica gel thin-layer plate [0118] 3 sample [0119] 4 eluent [0120] 5 container [0121] 11 liquid chromatography device [0122] 12, 13 container [0123] 14 solenoid valve [0124] 15 mixer [0125] 16 pump [0126] 17 injector [0127] 18 column [0128] 20 fraction collector