Method for the rapid analysis of a mixture of a number of substances by chromatography

Claim 1

A method of rapid analysis of a mixture of a predetermined number of known substances by chromatography wherein, in a first step, a chromatographic column having a retention time within the range of a few seconds to two minutes in the case of the most strongly retained substance is calibrated by passing separately through the column in the absence of each of the other substances used for the formation of the mixture which is to be subsequently analyzed in said column and by recording at the exit the pulse response of each separate substance aforesaid in respect of said column; in a second step, the mixture to be analyzed is passed through the same said column and the total pulse response corresponding to said mixture is recorded; in a third step, relating the total pulse response corresponding to the mixture and the specific pulse responses of each separate substance to determine the concentration of each separate substance aforesaid in the mixture, wherein in the first step and in the case of a given carrier gas flow velocity, the specific pulse response of each of said substances i aforesaid is sampled as it is being recorded and the values h i (t j ) of said response which is surface-normed are stored in memory at each sampling instant t j ; in the second step, the total pulse response corresponding to said mixture is sampled as it is being recorded and the values x (t j ) of said response are stored in memory at each sampling instant t j ; in the third step, the concentration of each of the substances in the mixture is calculated by using the method of least squares by minimizing the sum: ##EQU8## where m is the number of points sampled and α i represents the mass of molar percentages of each of the n substances i in the mixture and there is then solved the system of n linear equations having n unknown quantities α i corresponding to the equation δS/δα i = 0 in the case of each substance i from 1 to n.

Claim 2

A method of rapid analysis of a mixture of a predetermined number of known substances by chromatography wherein, in a first step, a chromatographic column having a retention time within the range of a few seconds to two minutes in the case of the most strongly retained substance is calibrated by passing separately through the column in the absence of each of the other substances used for the formation of the mixture which is to be subsequently analyzed in said column and by recording at the exit the pulse response of each separate substance aforesaid in respect of said column; in a second step, the mixture to be analyzed is passed through the same said column and the total pulse response corresponding to said mixture is recorded; in a third step, relating the total pulse response corresponding to the mixture and the specific pulse responses of each separate substance to determine the concentration of each separate substance aforesaid in the mixture, wherein in the first step and in the case of a given carrier gas flow velocity, the specific pulse response of each of said substances i aforesaid is sampled as it is being recorded and the values h i (t j ) of said response which is surface-normed are stored in memory at each sampling instant t j ; in the second step, the total pulse response corresponding to said mixture is sampled as it is being recorded and the values x (t j ) of said response are stored in memory at each sampling instant t j ; in the third step, the concentration of each of the substances in the mixture is calculated by using the method of least squares by minimizing the sum: ##EQU8## where m is the number of points sampled and α i represents the mass of molar percentages of each of the n substances i in the mixture and there is then solved the system of n linear equations having n unknown quantities α i corresponding to the equation δS/δα i = 0 in the case of each substance i from 1 to n.

Claim 3

A method of rapid analysis of a mixture of a number of substances this number being larger than 2 by chromatography wherein, in a first step, a chromatographic column having a retention time within the range of a few seconds to two minutes in the case of the most strongly retained component, is calibrated by passing separately through the column each of the substances used for the formation of the mixture which is to be subsequently analyzed in said column and by recording at the exit the pulse response of each substance aforesaid in respect of said column; in a second step the specific pulse response of each of said substances i is sampled at times t j as it is being recorded and the values h i (t j ) of said response which is surface-normed, are stored in memory at each sampling instant t j ; in a third step the coefficients h ij of a matrix H are determined, said coefficients corresponding to the sum of the products of two values h i (t k ) and h j (t k ) for all values of sampling instant t k , and then the value of the elements h ij of the inserted matrix H are also determined; in a fourth step the mixture to be analyzed is passed through the column, the total pulse response corresponding to said mixture is sampled as it is being recorded and the values x(t j ) of said response are stored in memory at each sampling instant t j ; then in a first step the values of coefficients b i are determined, each coefficient being equal to the sum of products of two values h i (t k ) and x (t k ) for all values of sampling instant t k , and in the final step the values of the molar percentage of each of the n substances i in the mixture are determined by multiplying the values of b j and h ij for all values of j.

Claim 4

A method of rapid analysis of a mixture of a number of substances this number being larger than 2 by chromatography wherein, in a first step, a chromatographic column having a retention time within the range of a few seconds to two minutes in the case of the most strongly retained component, is calibrated by passing separately through the column each of the substances used for the formation of the mixture which is to be subsequently analyzed in said column and by recording at the exit the pulse response of each substance aforesaid in respect of said column; in a second step the specific pulse response of each of said substances i is sampled at times t j as it is being recorded and the values h i (t j ) of said response which is surface-normed, are stored in memory at each sampling instant t j ; in a third step the coefficients h ij of a matrix H are determined, said coefficients corresponding to the sum of the products of two values h i (t k ) and h j (t k ) for all values of sampling instant t k , and then the value of the elements h ij of the inserted matrix H are also determined; in a fourth step the mixture to be analyzed is passed through the column, the total pulse response corresponding to said mixture is sampled as it is being recorded and the values x(t j ) of said response are stored in memory at each sampling instant t j ; then in a first step the values of coefficients b i are determined, each coefficient being equal to the sum of products of two values h i (t k ) and x (t k ) for all values of sampling instant t k , and in the final step the values of the molar percentage of each of the n substances i in the mixture are determined by multiplying the values of b j and h ij for all values of j.