Chromatographic Data System Processing Apparatus
20220373523 · 2022-11-24
Inventors
Cpc classification
G01N30/8693
PHYSICS
International classification
Abstract
A chromatographic data system processing apparatus includes a liquid feeder, a sample injector, a column that separates samples, a detector, a controller that processes a detected result of the detector, and a data processor that examines and sets operations of the liquid feeder, the column and the detector, and a measurement condition. The data processor generates a three-dimensional graph having three axes related to a pressure, a time, and a number of theoretical plates based on data or variables indicating a relationship between the number of theoretical plates and a flow rate, and data or variables indicating a relationship between the pressure and the flow rate. The chromatographic data system processing apparatus can easily obtain a separation condition for obtaining performance from a three-dimensional graph including a pressure drop, a hold-up time and a number of theoretical plates.
Claims
1. A control method for a chromatographic data processor that analyzes and processes data of an analysis condition and a detection result of a chromatograph, comprising: an input step inputting data or variables indicating a relationship between a number of theoretical plates and a flow rate, and an output step outputting a partial differential coefficient in a function (z.sub.k) of two independent variables (x.sub.i, x.sub.j) selected from a variable (x.sub.1) indicating the flow rate, a variable (x.sub.2) indicating a length, a variable (x.sub.3) indicating a pressure, and a variable (x.sub.4) indicating a time.
2. The control method according to claim 1, wherein the output step outputs a three-dimensional graph of the partial differential coefficient.
3. The control method according to claim 1, wherein the output step outputs a dimensionless efficiency standardized with using the independent variable to be partially differentiated based on the partial differential coefficient.
4. The control method according to claim 3, wherein the output step outputs a third dimensionless efficiency calculated based on a first dimensionless efficiency and a second dimensionless efficiency.
5. The control method according to claim 3, wherein the output step outputs the dimensionless efficiency as a three-dimensional graph and/or separation condition analysis.
6. A chromatographic data processor that analyzes and processes data of an analysis condition and a detection result of a chromatograph, wherein the chromatographic data processor is programmed to input data or variables indicating a relationship between a number of theoretical plates and a flow rate, and the chromatographic data processor is further programmed to output a partial differential coefficient in a function (z.sub.k) of two independent variables (x.sub.i, x.sub.j) selected from a variable (x.sub.1) indicating the flow rate, a variable (x.sub.2) indicating a length, a variable (x.sub.3) indicating a pressure, and a variable (x.sub.4) indicating a time.
7. The chromatographic data processor according to claim 6, wherein the chromatographic data processor is further programmed to output a three-dimensional graph of the partial differential coefficient.
8. The chromatographic data processor according to claim 6, wherein the chromatographic data processor is further programmed to output a dimensionless efficiency standardized with using the independent variable to be partially differentiated based on the partial differential coefficient.
9. The chromatographic data processor according to claim 8, wherein the chromatographic data processor is further programmed to output a third dimensionless efficiency calculated based on a first dimensionless efficiency and a second dimensionless efficiency.
10. The chromatographic data processor according to claim 8, wherein the chromatographic data processor is further programmed to output the dimensionless efficiency as a three-dimensional graph and/or separation condition analysis.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0065] Hereinafter, the Literature 1 and the Literature 2 will be mathematically unified, and disclosures according to an invention devised from the understanding based on the mathematical unification will be shown.
(1) Bidirectional Transformation Method LRT
[0066] As one of the disclosures, Logarithmically Rotational Transformation (LRT) based on a logarithmic axis representation such as log Π.
[0067] t.sub.0 described above is expressed by Equation 2 using the variables u.sub.0 and L in the above Equation 1.
[0068] The Equations 1 and 2 are logarithmic representations and can be represented into Equations 3 and 4.
[0069] Equations 3 and 4 can be represented in a matrix notation and can be regarded as a kind of axis rotational transformation (Equation 5).
[0070] This means that N (u.sub.0, L) can rotate to N (Π, t.sub.0) through a logarithm, that is, coordinate conversion can be performed. Since the logarithm can be returned to an antilogarithm, it is a one-to-one mapping from a basal plane (u.sub.0, L) to a basal plane (Π, t.sub.0), and vice versa. Precisely, it is a bijective linear transformation that multiplies the rotational transformation by a scalar magnification √2. It is regarded that the three-dimensional graph of N (u.sub.0, L) is different from the three-dimensional graph of N (Π, t.sub.0) only in the axis to be expressed, and contents to be expressed are equivalent. However, this relationship is an intuitive representation for the first time being represented on the logarithmic axis. Mathematically, from an idea that links a relationship of a mathematical product and a quotient between u.sub.0 and L to a relationship of a sum and a difference between them through logarithm, a representation easy to understand can be obtained. In the Literature 1, a target is considered to be a five-dimensional space V (u.sub.0, L, Π, t.sub.0, N), but according to the present disclosure, the target is divided into two three-dimensional partial spaces T.sub.1 (u.sub.0, L, N) and T.sub.2 (Π, t.sub.0, N), as shown in
[0071] As for the way to see chromatography, T.sub.1 (u.sub.0, L, N) is a space represented by a three-dimensional graph showing N obtained by first fixing separation conditions such as a mobile phase, an analytical specie and a column temperature under a precondition of an optional column filler and freely changing u.sub.0 and L. In response to this, T.sub.2 (Π, t.sub.0, N) is a transformation destination from the basal coordinate of u.sub.0 and L to the basal coordinate Π and t.sub.0. That is, two-dimensional degrees of freedom of u.sub.0 and L are inherited to all degrees of freedom of Π and t.sub.0. If there is a certain column, L is constant but u.sub.0 is variable. It is understood that, if u.sub.0 is moved, not only to but also Π changes accordingly, so that all sets of u.sub.0 and L correspond to sets of Π and t.sub.0.
[0072] WO 2014/030537 describes KPA (Kinetic Plot Analysis), that is, KPL (Kinetic Performance Limit). KPL can be regarded as representing a cross section (t.sub.0, N) at a certain Π when T.sub.2 (Π, t.sub.0, N) is cut with the certain Π. When u.sub.0 is changed using a column of a certain L, the N (u.sub.0) curve at the certain L is drawn on a (u.sub.0, N) plane of the certain L. Further, a T.sub.1 (u.sub.0, L, N) space is obtained by sweeping the above L. Since it is a surjection from T.sub.1 (u.sub.0, L, N) to T.sub.2 (Π, t.sub.0, N), it is clearly determined that a set of (u.sub.0, L) to a set of (Π, t.sub.0) is a one-to-one correspondence. That is, a two-dimensional graph (t.sub.0, N) indicated by KPL is a cross section (t.sub.0, N) of a certain Π in the (t.sub.0, N) space, and each point indicated by a curve N (t.sub.0) or t.sub.0 (N) of the specific Π expressed by KPL always goes back to coordinates somewhere in the original T.sub.1 (u.sub.0, L, N) space. The mapping point of the T.sub.2 (Π, t.sub.0, N) space never goes out of the T.sub.1 (u.sub.0, L, N) space and never duplicates. KPL is a cross section in the T.sub.2 (Π, t.sub.0, N) space at a specific Π, and original elements thereof are necessarily provided in advance in the T.sub.1 (u.sub.0, L, N) space.
[0073] In
[0074] A circle shown on the three-dimensional graph in
[0075] It can be understood that this is a reversible relationship indicating a transfer from a resultant T.sub.2 representation form required as performance to a causal representation form of T.sub.1 to be answered as a separation condition or a transfer in a reverse direction. The LRT can easily provide the basal coordinates of Π and t.sub.0, which can be obtained as a result that an analysis operator cannot immediately estimate by just looking at the cause setting variables u.sub.0 and L. Here, the basal coordinate referred to corresponds to a basal plane of a three-dimensional graph. z on a vertical axis is set as N, and the basal coordinate (x, y) is (u.sub.0, L) or (Π, t.sub.0).
[0076] Further, since the column length L available to general users is discrete as 50 mm, 100 mm, and 150 mm, there is an advantage that a cause input L of T.sub.1 can be discretely expressed and u.sub.0 can be evaluated continuously can be evaluated. Since this T.sub.1 can be LRT-transformed to a three-dimensional graph of T.sub.2, a discrete representation can correspond to the T.sub.2 graph one-to-one, as a performance result. This is a very convenient representation for the users as a real solution. The operation and representation form of a chromatography data system (CDS) related to these three-dimensional graphs can correspond not only to a bidirectional transformation of LRT but also a bidirectional transformation between a logarithm and an antilogarithm and a discrete representation of L. In addition, when the user indicates an arbitrary point on the three-dimensional graph, three sets of values of (u.sub.0, L, N) and (Π, t.sub.0, N) can be shown. When arbitrary two points are indicated, a difference between the three axial directions can also be expressed. For example, an increment of N is an increment of Π and t.sub.0.
(2) Generalized Representation Form
[0077] The logarithmically rotational transformation LRT is generalized and extended. Variables are generalized with x.sub.i and four variables of i=1, 2, 3, 4 are introduced when x.sub.1=u.sub.0, x.sub.2=L, x.sub.3=Π, and x.sub.4=to. In the four variables, Equation 1 and Equation 2, that is, Equation 6 and Equation 7, have a subordination relationship, and since there are four variables and two equations, there two independent variables. The number of combinations of selecting two variables from the four variables is 6 of .sub.4C.sub.2.
[0078] In addition, when making a three-dimensional graph, two independent variables can be assigned to a first dimension axis and a second dimension axis, such as a basal coordinate (x.sub.i, x.sub.j). At this time, if the order of the first dimension axis and the second dimension axis is distinguished, there are 12 combinations of the permutation number .sub.4P.sub.2. As described above, a logarithmic representation such as log x.sub.1 can be used for the basal coordinate. Up to here, the z axis is discussed with respect to N, but other functions can be introduced as a similar basal plane approach. In order to extend to t.sub.E.sup.−1 and E.sup.−1E−1, a z.sub.k representation wherein k=1, 2, 3, 4, . . . , etc., is introduced and it can be defined that z.sub.1=N, z.sub.2=t.sub.E.sup.−1, z.sub.3=E.sup.−1, and z.sub.4=t.sub.p.sup.−1. For example, it is represented that z.sub.1=N (x.sub.3, x.sub.4), and z.sub.2=t.sub.E.sup.−1(x.sub.1, x.sub.2). The reason why there are indexes expressed by reciprocals is to unify and impress as an optimization problem that maximizes the axis above the objective function z.sub.k . As z.sub.k, H.sup.−1, H.sup.−2, H.sup.−3, . . . , etc., which are simply powers and reciprocals of H, H.sup.2, H.sup.3, . . . , etc., can also be adopted. Further, an arbitrary index that multiplies each of the basal coordinates x.sub.i, x.sub.j, . . . , etc., can also be adopted.
[0079] From Equation 8, N is a function proportional to L, and also from the Equations 1 and 2, Π and t.sub.0 are also functions proportional to L, respectively. That is, in the three-dimensional graph (Π, t.sub.0, N), L can be regarded as one of extensive variables.
[0080] t.sub.E is a time obtained by dividing t.sub.0 by N.sup.2, and represents an impedance time, and t.sub.p is a time obtained by dividing t.sub.0 by N and represents a plate time.
(3) New index Based on Partial Differential Coefficient
[0081] On the other hand, the slop in each direction of the basal coordinate axis, that is, the partial differential coefficient, when N (Π, t.sub.0) is represented by the curved surface of the three-dimensional graph can be taken as a specific determination evaluation index.
[0082] First, simply, the slope of N with respect to the change of Π when to is constant in the three-dimensional graph N (Π, t.sub.0) is a partial differential coefficient c.sub.N/Π (Equation 12). c.sub.N/Π (Π, t.sub.0) indicating a simple slop is set as a slope of the curved surface in the three-dimensional graph, which is a function in which to is fixed with a partial differential coefficient, an N increment per Π is denoted, and a dimension is included, and is defined over the entire basal coordinate.
[0083] A general mathematical representation can be made as shown in Equation 13 from the properties of partial differential coefficient.
[0084] Here, x, y, and z are variables, I, n, and m are constants, and can be similarly expanded to Equation 14.
(4) Introduction of Impedance Time
[0085] According to the Literature 2 or the like, the impedance time t.sub.E can be introduced, and the reciprocal thereof is re-indicated here as Equation 15 as shown in Equation 9 above.
[0086] On the other hand, a theoretical plate equivalent height H (u.sub.0) is obtained from a minimum and best theoretical plate equivalent height H.sub.min=H (u.sub.0, opt) with the optimal linear velocity u.sub.0,opt. When u.sub.0=u.sub.0,opt, Equation 16 is obtained by using this constant H.sub.min.
Π=H.sub.min.sup.2N.sup.2t.sub.0.sup.−1 (Equation 16)
[0087] As compared Equation 16 with a general formula (Equation 14), a coefficient n=2 appears and a representation of Equation 17 is obtained. Equation 11 in which the coefficient n=2 has a feature is limited when u.sub.0=u.sub.0,opt, and H.sub.min is offset in the calculation process.
[0088] Here, c.sub.N/Π is a partial differential coefficient value defined by Equation 12. When c.sub.N/Π (Π, t.sub.0) is expressed as a function defined by the basal coordinates, the form of Equation 18 is obtained.
[0089] Here, since u.sub.0,opt constant conditions are imposed, in fact, Π and t.sub.0 cannot move on the basal plane of the whole coordinate area freely, and are constrained by the rule of Equation 19 by the L of a medium extensive variable by the Equations 1 and 2.
Πt.sub.0=L.sub.2 (Equation 19)
[0090] Up to here, although being limited to the constant H.sub.min under the optimal condition u.sub.0,opt, the basal coordinate must be extended to (Π, t.sub.0) the whole area in order to extend to the real solution. μ.sub.N/Π as a kind of new adjustment factor devised from Equations 12 and 17 is introduced (Equation 20). μ.sub.N/Π is equal to 1 for the optimal condition u.sub.0=u.sub.0,opt, but is standardized so as to be a value other than 1 in other basal coordinate areas. Accordingly, μ.sub.N/Π can be used as an index such as efficiency. As a result, μ.sub.N/Π is a dimensionless standardization factor and has the ability to adjust to obtain the value c.sub.N/Π of Equation 17 obtained by using H.sub.min only in the case of u.sub.0,opt.
(5) PAE (Pressure-Application Efficiency)
[0091] The following function μ.sub.N/Π (Π, t.sub.0) is defined as a Pressure-Application Efficiency (PAE) (Equation 20). By comparing the function with Equation 18, the position of μ.sub.N/Π can be understood. μ.sub.N/Π (Π, t.sub.0) is a function defined by basal coordinates.
[0092] Equation 18 is an ideal equation that holds only when u.sub.0=u.sub.0,opt. That is, although Equation 18 does not hold in the case of u.sub.0 other than u.sub.0,opt, Equation 21 having a form close to Equation 18 can be expressed by introducing an adjustment factor μ.sub.N/Π as a transformation of ideas.
[0093] The way to obtain the actual μ.sub.N/Π (Π, t.sub.0) is to first obtain the slope c.sub.N/Π (Π, t.sub.0)of the three-dimensional graph at each point of the basal coordinate (Π, t.sub.0), and multiply each by a coefficient 2. Next, μ.sub.N/Π (Π, t.sub.0) is obtained by multiplying Π of the basal coordinate thereof and dividing by N (Π, t.sub.0) of the coordinate (Equation 21).
[0094] Similarly, the Time-Extension Efficiency (TE.sup.2) can also be defined as μ.sub.N/t (Π, t.sub.0) (Equation 22).
[0095] It is described that the z axis is a special direction to the basal plane, but mathematically simply expresses the slope of the curved surface in the three-dimensional graph from a different perspective. Therefore, PAE for hold-up time t.sub.0 can also be defined as μ.sub.tΠ (Π, t.sub.0) (Equation 23). In other words, the above PAE is considered to be PAE for the number of theoretical plates N (Equation 20).
[0096] Here, an explanation of the doctrine of equivalents will be added. Since the pressure drop ΔP and the velocity length product Π or the general term pressure P are proportional to each other, it is considered that all the discussions around this, which are regarded as ratios, are equivalent. Similarly, the retention time t.sub.R and the hold-up time to have the same relationship, and can be used equivalently if careful consideration is given to the retention factor and the gradient elution. The flow rate and the linear velocity u.sub.0 can also be used equivalently as long as it is understood that the flow rate and the linear velocity u.sub.0 correspond to the porosity and cross-sectional area of the column, respectively.
[0097] In the context of the present disclosure, there is an abstract and ideal discussion modeling, and the present disclosure is built on a mathematical pressure driven HPLC model composed and defined only by H (u.sub.0) and K.sub.v.
(6) Generalization of Partial Differential Coefficient System
[0098] Representations based on the following generalization are also possible. Equation 24 holds at the time of u.sub.0,opt.
[0099] Here, c.sub.k/j is predefined as Equation 25.
[0100] Next, a dimensionless efficiency μ.sub.k/i is defined as Equation 26 as described above. At the time of μ.sub.0,opt, μ.sub.k/i is standardized to 1. The coefficient n is the degree derived from Equation 9.
[0101] Here, when obtaining a partial differential coefficient, the variable x.sub.j of a suffix j is fixed and Equation 27 can be represented.
[0102] In addition, μ.sub.k/i is obtained in the entire area of the basal coordinate as Equation 28.
[0103] In terms of total differentiation, the function N can be represented by Equation 29 using partial differential coefficients.
[0104] Here, it is expressed as Equation 30, and n=½ and m=½.
[0105] Since μ.sub.k/j is mathematically derived from the slope of the curved surface in the three-dimensional graph, there is a relationship of Equation 31. If two independent variables and the three axes of the function z are mathematically handled without distinction, μ.sub.t/Π in derived from the slope obtained by fixing N can also be calculated.
[0106] For example, if being locally constant, μ.sub.t/Π in can be integrated as shown in Equation 32.
[0107] Similarly, μ.sub.t/Π can also be represented exponentially (Equation 33).
[0108] Further, it is expanded to a partial differential coefficient system as a series when k of z.sub.k equals to 5, 6, 7, . . . , c.sub.N/Π to z.sub.5, μ.sub.N/Π to z.sub.6 can also be expanded sequentially as a three-dimensional graph.
(7) Van Deemter Equation
[0109] The Van Deemter equation is used to demonstrate concrete calculations (Equation 34).
[0110] This obtains regression coefficients A, B, and C by curve-fitting several experimental values of an H-u.sub.0 plot. The H-u.sub.0 profile is generated due to factors such as physical diffusion, but in the present disclosure K.sub.v and Equation 34 are used as a curved surface profile generator for generating a three-dimensional graph.
[0111] As shown in
[0112] At the time of u.sub.0,opt, surely μ.sub.N/Π=1.
[0113] Here,
(Equation 37) is obtained.
[0114] On the other hand, PAE for t.sub.0 is shown in
[0115] At the time of u.sub.0,opt, similarly μ.sub.t/Π=1.
[0116] All three-dimensional graphs in
[0117] μ.sub.N/Π (Π, t.sub.0) is 1 at when the linear velocity is the optimal u.sub.0,opt. Although the slope of higher pressure is less than 1, it is not merely a gentle slope and not a large decrease in efficiency. That is, an increase in number of theoretical plates per pressure can be expected with a good efficiency that is almost equal to an ideal u.sub.0,opt. For example, as one of guidelines, it is possible to search for a separation condition as a practical range of μ.sub.N/Π of 0.5 or more as a practical range as long as the separation is allowed in a high-speed analysis time area which is not ideal. This is an advantage of quantitatively overlooking using μ.sub.N/Π in the basal coordinate (Π, t.sub.0).
[0118] On the other hand, the slope on the low pressure side of μ.sub.N/Π (Π, t.sub.0)=1 is greater than 1, which seems to be efficient at first sight, but this is not necessarily the case. The reason for showing excessive efficiency means that it is easy to reach μ.sub.N/Π (Π, t.sub.0)=1 by setting a better set of L and u.sub.0. In the case of one or more slopes, it is relatively easy to increase N more than u.sub.0,opt if it is a set of L and u.sub.0 which increases the pressure slightly.
[0119] An index such as μ.sub.N/Π is a dimensionless ratio that standardizes a value at the time of u.sub.0,opt to 1. In addition, in the case of exceeding 1, it may be better to refer to a Pressure-Application Coefficient (PAC) rather than efficiency.
EXAMPLES
[0120] Examples of the present disclosure will be described in detail with reference to the drawings.
[0121] In
[0122] In the analytical column 1260, the sample is separated for each analyte and sent to a detector 1270. Light is irradiated in a cell 1280 of the detector 1270, and a waveform of the chromatogram is obtained from the signal intensity. The sample and the eluent are then sent to a waste liquid tank 1290.
[0123]
[0124] As shown in
[0125] The data processor 1360 may not be connected with the controller 1350 to be independent from the liquid chromatography system. In a case where the data processor 1360 is independent, the data processor 1360 may perform processing based on the conditions input from an input unit 1370. The data processor 1360 corresponds to the chromatographic data system processing apparatus described in the claims.
[0126]
[0127] Alternatively, by designating the respective coordinate axes, Π, and t.sub.0, for example, from a first axis and second axis setting unit (760) after transformation, an LRT transformer (730) executes the rotation of the logarithmic axis and the scaling transformation. The result is transferred via a three-dimensional graph generator (740) after transformation to generate a three-dimensional graph, and the three-dimensional graph of N (Π, t.sub.0) shown in
The result can also be printed as necessary.
[0128]
[0129] By specifying, for example, Π and N respectively from the a xi, zk setting unit (870), a partial differential coefficient c.sub.k/i, calculator (830) calculates the partial differential coefficient. First, the result can be displayed from the output unit (1380) in a three-dimensional graph of c.sub.N/Π (Π, t.sub.0) as necessary. Next, the result is displayed as a three-dimensional graph of μ.sub.N/Π (Π, t.sub.0) shown in
[0130] The flow rate F (ml/min) is proportional to the linear velocity u.sub.0 (mm/s). These correspond to a variable x.sub.1, and the cross sectional area (m.sup.2) of the inner diameter of the column is related to the porosity of the filled state. A variable x.sub.2 having a length dimension (m) is the column length L (mm). A variable x.sub.3 corresponding to the pressure is the column pressure drop ΔP (MPa), which is also proportional to Π (m.sup.2/s). Π is called the velocity length product or the pressure-driven strength. A time variable x.sub.4 is the hold-up time t to (s) or the retention time t.sub.R (min) The number of theoretical plates N is a variable or function of z.sub.1 and is inversely proportional to the theoretical plate equivalent height H (μm). The function z.sub.2 is the reciprocal of the impedance time t.sub.E, the function z.sub.3 is the reciprocal of the separation impedance E, and the function z.sub.4 is the reciprocal of the plate time t.sub.P.
[0131]
[0132] The flowchart of
[0133] The flowchart of
[0134] The three-dimensional graph can also be expressed with a logarithmic axis. For example, a three-dimensional graph expressed by a logarithmic coordinate (log u.sub.0, log L) is expressed as (log Π, log u.sub.0) by LRT transformation. Further, a PAE based on the slope on N (log Π, log u.sub.0) can also be defined.
[0135] Alternatively, in obtaining a slope from the graph of function N (log Π, log u.sub.0) or defining some sort of efficiency, the PAE can be calculated on N (log Π, log u.sub.0) by LRT transformation.
[0136] In addition, these can also be generalized representation.
[0137] Next, an example of an analysis example of separation conditions using a three-dimensional graphic representation of the liquid chromatographic data system processing apparatus of the present disclosure will be described. As an example of the utilization shown in
[0138] Next, when transforming
[0139] This designated circle is also transformed into
[0140] μ.sub.N/Π and μ.sub.t/Π are called PAC (Pressure-Application Coefficient), and μ.sub.N/t is called TEC (Time-Extension Coefficient). Equations 24 to 28 are the definition equations.
[0141] The application of PAC (Pressure-Application Coefficient) and TEC (time extension coefficient) is shown in detail in the case of six approaches.
[0142]
[0143] The pressure upper limit approaches 20 MPa around N=5,000 or more and the u.sub.0,opt line cannot be climbed along. In order to further increase N from here, a KPL method is adopted which is a method of climbing a hill under a constant condition that the upper limit pressure is 20 MPa. However, it is understood that in the KPL method, the climbing method is comparatively gentle, and only about N=7,000 is obtained, so that the efficiency of increasing N is worse than the Opt method. PAC and TEC are introduced as coefficients quantitatively indicating this efficiency.
[0144] In addition, as shown in
[0145] In the Opt method, the u.sub.0,opt line or the vicinity thereof is selected as an optimal separation condition, but the minimum H.sub.min is obtained the u.sub.0,opt line. Therefore, if an arbitrary L column is attached, the maximum N at this L is inevitably obtained. At the same time, t.sub.0 and Π are unambiguously calculated. That is, in a five-dimensional space (Π, t.sub.0, N, u.sub.0,opt, L), a so-called straight line u.sub.0,opt line determined by a constant u.sub.0,opt is shown. For example, if a user requests N=5,000, he or she can see contour lines on a height surface of N=5,000, i.e., on hilly slopes (
[0146] Hereinafter, six approaches are shown.
1. Speeding-up of t.sub.0 under constant condition of N [0147] (1) Extension to the high Π area [0148] (2) Low Π area (movement to upper limit pressure Π.sub.max)
2. High separation of N under constant condition of t.sub.0 [0149] (1) Extension to the high Π area [0150] (2) Low Π area (movement to upper limit pressure Π.sub.max)
3. Expansion under upper limit pressure [0151] (1) Speeding-up (reduction in t.sub.0) [0152] (2) High separation (increase in N)
[0153] Approach 1-(1) is an optimization method that aims to realize high speeding-up while ensuring a constant N (
[0154] As shown in
[0155] Approach 1-(2) corresponds to a case where an arbitrary N is expected to be obtained, and the intersection point of the u.sub.0,opt line and the contour line of N is already above the upper limit pressure. The approach 1-(2) is a method of lowering the pressure, that is, making the pressure belongs to the low Π area and securing N along the contour line while extending the time, so as to obtain this N (
[0156] First, the method starts from the intersection point of the contour line of N=5,000 and the u.sub.0,opt line (Opt method). In a case where the upper limit pressure is 10 MPa, it is inevitable to lower the pressure to 10 MPa along the contour line of N=5,000. The fact that μ.sub.t/Π is 1.39 means that at the intersection point of 10 MPa and the contour line, it is possible to speed up 1.39 times from the vicinity of the u.sub.0,opt line, by just increasing the pressure slightly, that is, increasing the Π increment. Conversely, the low Π area is an area where the high speed performance is inevitably extremely sacrificed when trying to obtain the high separation performance which is disproportionate. (
[0157] Approach 2-(1) is an optimization method that aims to realize high separation while ensuring a constant to (
[0158] Approach 2-(2) corresponds to a case where an arbitrary to is expected to be obtained, and the intersection point of the u.sub.0,opt line and the horizontal line of a constant to is already above the upper limit pressure. The approach 2-(2) is a method of lowering the pressure, that is, making the pressure belongs to the low Π area and reaching the upper limit pressure along the to horizontal line while dropping N, so as to obtain this to (
[0159] First, the method starts from an intersection point of the horizontal line projected on a basal plane with a constant t.sub.0=10 s and the u.sub.0,opt line (Opt method). In a case where the upper limit pressure is 10 MPa, it is inevitable to lower the pressure along the horizontal line of a constant t.sub.0=10 s, and the separation condition is moved to the left direction from the u.sub.0,opt line to 10 MPa.
[0160] It is means that at the time of 10 MPa, μ.sub.N/Π is 1.16, and at the intersection point of 10 MPa and the horizontal line of t.sub.0=10 s, it is possible to perform high separation 1.16 times from the vicinity of the u.sub.0,opt line, by just increasing the pressure slightly, that is, increasing the Π increment. Conversely, in order to obtain the high speed performance of t.sub.0=10 s, the pressure is lowered, the pressure reduction rate is increased, and N gets worse. Therefore, the separation performance comes to be remarkably sacrificed. Since the approach 2-(2) uses the low Π area of barren area as in the approach 1-(2), it is inevitable to sacrifice the separation performance to a large extent when trying to obtain the extremely high speed performance (
[0161] Approach 3 is a so-called KPL method that ensures a constant pressure. First, the approach 3-(1) is a speeding-up method (
[0162] First, the method starts from an intersection point of a vertical line of ΔP=20 MPa and the u.sub.0,opt line (Opt method). At the intersection point, t.sub.0=11 s is obtained, and N=5,620 (
[0163] In a case where to is speeded up to 3 s, N=2,760, which is remarkably reduced, but μ.sub.N/t remains at 1.18; if the sacrifice of N is acceptable, it can be said that the approach 3-(1) is a reasonable speeding-up method in which the coefficient value gets worse.
[0164] On the other hand, the approach 3-(2) is a high separation method (
[0165] The method starts from an intersection point of a vertical line of ΔP=20 MPa and the u.sub.0,opt line (Opt method). At the intersection point, t.sub.0=11 s is obtained, and N=5,620. In order to further increase N from here, the time is increased from the u.sub.0,opt line vertically upwards for 15 s or 20 s. Also in a case of 20 s, μ.sub.N/t=0.92, it is considered that N can be increased by using time relatively efficiently, which is an example of an effective KPL method. (
[0166] In fact, as for the low Π area and the high Π area, the former is an area of u.sub.0 lower than u.sub.0,opt, and the latter is an area of u.sub.0 higher than u.sub.0,opt. On the contour plot, only the u.sub.0 ,.sub.opt line is expressed. Since u.sub.0 is not expressed positively, the low Π area is expressed for convenience. As described above, although the speeding-up is excellent in the area of high u.sub.0, the PAC such as μ.sub.N/Π and μ.sub.t/Π becomes 1 or less. On contrast, the PAC exceeds 1 in the low Π area. For example, in the low Π area, when the pressure is increased just little, this ratio increases and N increases greatly. Conversely, it means that even if N is lowered, there is no effect of lowering the pressure to such an extent.
[0167] First, a t.sub.0 constant transformation efficiency η.sub.t is defined.
[0168] For preparation, the numerator and denominator of Equation 20 are turned over to obtain Equation 40.
[0169] Therefore, μ.sub.Π/N indicates a relationship between PAC μ.sub.N/Π related to N and a reciprocal, as shown in equation 41.
μ.sub.Π/N=(μ.sub.N/Π).sup.−1 (Equation 41)
[0170] The t constant transformation efficiency η.sub.t should have a value from 0 to 1 in order to position the efficiency. Therefore, the high Π area corresponds to μ.sub.N/Π, and the low Π area corresponds to μ.sub.Π/N. It is requested that the maximum efficiency value 1 on the u.sub.0,opt line. In this way, the t constant transformation efficiency η.sub.t can be expressed by one equation using PAC μ.sub.N/Π related to N (Equation 42).
log η.sub.t=−|log μ.sub.N/Π| (Equation 42)
[0171] The above is the t.sub.0 constant transformation efficiency η.sub.t. Similarly, an N constant transformation efficiency η.sub.N can also be defined using PAC μ.sub.t/Π in related to t.sub.0 (Equation 43).
log η.sub.N=−|log μ.sub.t/Π| (Equation 43)
[0172] In addition, a Π constant transformation efficiency ηΠ can also be defined using TEC μ.sub.N/t (Equation 44).
log ηΠ=−|log μ.sub.N/t| (Equation 44)
[0173] Here, the meanings of the x constant transformation efficiencies η.sub.N, η.sub.t and η.sub.Π are looked back. The contour plot is a graph expressing three variables Π, t.sub.0, and N. Each constant transformation efficiency keeps one of the three variables constant and corresponds to the partial differential coefficient of the remaining two variables. In the high Π area, a short t.sub.0 as high speed performance or high separation performance N can be obtained under specific transformation efficiency by applying a pressure.
[0174]
[0175] In contrast, in
[0176] Similarly in
[0177]
[0178] However, efficiency η system is ideal for searching for maximum value 1. To analyze the vicinity of boundary line such as the u.sub.0,opt line, the efficiency η becomes an index not monotonically increase or decrease, which is also inconvenient. Hereinafter, it returns to practical PAC and TEC.
[0179] With reference to
[0180] In
[0181] Next, when an arbitrary to is to be obtained, first, a point B is found on the u.sub.0,opt line in
[0182] Quantitative optimization on the above KPL straight line, that is, the upper limit pressure will be described in detail.
[0183] If an arbitrary N is specified and a point C having a longer time than the vertex (intersection) of the previous triangular region is found, the separation condition is adopted. Here, if N is to be increased, t.sub.0 is further extended, so that the effectiveness of time extension can be measured with reference to TEC μ.sub.N/t. Even when seeing a state of TEC μ.sub.N/t by adding or subtracting t.sub.0, if the interval is longer than the intersection point, the effectiveness can be grasped as TEC of 1 or less.
[0184] In a case where an arbitrary to is specified and a point C having a longer time than the vertex (intersection) of the above triangular region is found, it is possible to further perform the speeding-up if it is determined that N is sufficiently large. It is possible to define the time reduction coefficient in the case of moving on the KPL straight line or define the N consumption coefficient as the reciprocal of μ.sub.N/t, i.e., μ.sub.t/N. In a case where N is sufficiently large, first, the contour plot is referred to again with the specified N.
[0185] If it is a coefficient of the same point such as point A, the following relationship (Equation 45) holds from the definition.
μ.sub.N/Π=μ.sub.N/tμ.sub.t/Π (Equation 45)
[0186] As can be seen, since TEC μ.sub.N/t is greater than 1 at a point slightly coming into the high Π area from the point A for example, μ.sub.N/Π is larger than μ.sub.t/Π, and PAC is 1 or less in this high Π area. Therefore, it is more effective and easier in high separation under a constant t than the speeding-up under a constant N. On the u.sub.0,opt line including the intersection above the triangular region, μ.sub.N/t=μ.sub.N/t=μ.sub.t/Π=1.
[0187] As described above, in a case where the point A (or the point B) is found on the u.sub.0,opt line by specifying N or t.sub.0, it is significant to search the separation condition for the triangular region up to the upper limit pressure. In this case, the pressure effectiveness in the triangular region can be quantitatively understood using each PAC.
[0188] In a case where the separation condition is searched on the KPL straight line of a constant pressure above the triangular region as the point C, the separation condition is adopted. If there is room to add or subtract N or t.sub.0, it is possible to quantitatively examine the effectiveness of the action to given to N using TEC.
[0189] In order to make it easier to understand mathematical representations and graphs, the square theoretical plate number Λ and an inverse hold-up time v.sub.0 are introduced.
Λ=N.sup.2
v.sub.0=t.sup.−1.sub.0
Π=H.sup.2Λv.sub.0=L.sup.2v.sub.0=u.sub.0L
[0190] As can be seen from the equations, by expressing with v.sub.0, the power of Π is divided by the product of Λ and v.sub.0. Since H.sup.2 is not a constant, but a ridge line is generated on the curved surface. By using the square theoretical plate number Λ instead of N on the vertical axis of the three-dimensional graph, the KPL curved surface can be expressed almost like a plane. In contrast, with respect to high speed performance, the larger the numerical value of the reverse hold-up time v.sub.0, the larger the high speed performance can be obtained.
[0191] The three-dimensional graphs are Λ (Π, t.sub.0) in
[0192] Commercial columns have discrete L such as 50 mm, 100 mm, and 150 mm. The variable of the present disclosure is a continuous real number representation, but in reality will be optimized with discrete L. However, the basic idea will follow even in practical application.
[0193] The present disclosure is not limited to the above embodiments, but it goes without saying that it extends to various modifications and equivalents included in the spirit and scope of the present invention.
LIST OF NUMERAL REFERENCES
[0194] 1 Liquid chromatography apparatus
[0195] 1210A Eluent (mobile phase)
[0196] 1210B Eluent (mobile phase)
[0197] 1220 pump
[0198] 1220A Pump
[0199] 1220B Pump
[0200] 1230 Mixer
[0201] 1240 Autosampler
[0202] 1250 Column oven
[0203] 1260 Analytical column
[0204] 1270 Detector
[0205] 1280 Cell
[0206] 1290 Waste liquid tank
[0207] 1350 Controller
[0208] 1360 Data processor
[0209] 1370 Input unit
[0210] 1380 Output unit