The Roche constant of the high performance gas chromatograph fixative is based on benzene, ethanol, methyl ethyl ketone, nitromethane and pyridine as the standard materials. They are determined at 100 ° C column temperature between the fixed solution and squalane to be tested. The difference ΔI of the index is retained and divided by 100 to obtain the characteristic constant of the fixed solution to be tested.
After studying the Roche constant and its determination method, McReynolds proposed an improvement scheme in 1970, using benzene, n-butanol, 2-pentanone, 1-nitropropane, pyridine, 2-methyl-2-pentanol, 10 kinds of substances such as iodine butane, 2-octyne, dioxane and cis-octahydroquinone were used as standard materials, and their ΔI values ​​between the fixed solution and squalane were measured at 120 ° C. The characteristic constants of the fixed liquid to be tested are represented by X', Y', Z', U', S', H, J, K, L and M, respectively, and are called the McMaster's constant.
McReynolds measured the Michael's constant of 226 fixatives. After induction, it was found that the first five substances were sufficient to express the relative polarity of the fixative, and the sum of the five terms was called the total polarity. The greater the total polarity, the stronger the polarity of the fixative.
The Roche constant is measured at a column temperature of 100 ° C, and the Beer's constant is measured at a column temperature of 120 ° C, and the structures of the standard materials used are different. The numerical relationship between the Roche constant and the Beer's constant is approximately: the Michaelson constant = the Rogowski constant × 100.
After studying the Roche constant and its determination method, McReynolds proposed an improvement scheme in 1970, using benzene, n-butanol, 2-pentanone, 1-nitropropane, pyridine, 2-methyl-2-pentanol, 10 kinds of substances such as iodine butane, 2-octyne, dioxane and cis-octahydroquinone were used as standard materials, and their ΔI values ​​between the fixed solution and squalane were measured at 120 ° C. The characteristic constants of the fixed liquid to be tested are represented by X', Y', Z', U', S', H, J, K, L and M, respectively, and are called the McMaster's constant.
McReynolds measured the Michael's constant of 226 fixatives. After induction, it was found that the first five substances were sufficient to express the relative polarity of the fixative, and the sum of the five terms was called the total polarity. The greater the total polarity, the stronger the polarity of the fixative.
The Roche constant is measured at a column temperature of 100 ° C, and the Beer's constant is measured at a column temperature of 120 ° C, and the structures of the standard materials used are different. The numerical relationship between the Roche constant and the Beer's constant is approximately: the Michaelson constant = the Rogowski constant × 100.
Servo Motor Diameter 190Mm,Electric Servo Motor,Servo Rotary Actuator,Direct Drive Servo Motor
Zhejiang Synmot Electrical Technology Co., Ltd , https://www.synmot-electrical.com