Separation and determination of parts-per-billion concentrations of gallium in biological materials.
Separation and determination of parts-per-billion concentrations of gallium in biological materials.
复制标题
生物材料中十亿分之一浓度镓的分离和测定。
作者：
N. Scott;D. E. Carter;Q. Fernando
通过将离子对GaCl/sub 4//sup -/ x R/sub 4/N/sup +/选择性萃取到己烷-甲基异丁基酮混合物中（R/sub 4/N/sup +/代表甲基三辛基铵离子），从生物基质的水性消化物中分离镓。萃取的镓物种与配体1，5-双（水杨醛）-硫代碳酰腙反应，形成络合物，当激发波长为395 nm时，该络合物在440 nm处发荧光。用于生物样品中0.10-40 ppb镓的测定，相对精密度为7%。在水溶液中，对荧光法的主要干扰是Fe/sup 3 +/、Fe/sup 2 +/、Cu/sup 2 +/和Zn/sup 2 +/。在水解液中，Fe/sup 3 +/被还原为Fe/sup 2 +/，Cu/sup 2 +/被S/sub 2/O/sub 3//sup 2 -/掩蔽。Fe/sup 2 +/和Zn/sup 2 +/不会萃取到有机相，不会干扰荧光法。
Gallium is separated from an aqueous digest of a biological matrix, by the selective extraction of the ion pair GaCl/sub 4//sup -/ x R/sub 4/N/sup +/, into a hexane-methyl isobutyl ketone mixture (R/sub 4/N/sup +/ represents the methyltricaprylammonium ion). The extracted gallium species reacts with the ligand, 1,5-bis(salicylidene)-thiocarbohydrazone, to form a complex that fluoresces at 440 nm when the excitation wavelength is 395 nm. This fluorometric method has been used to determine 0.10-40 ppb of gallium in biological materials with a relative precision of 7%. The principal interferences with the fluorometric method in aqueous solutions are Fe/sup 3 +/, Fe/sup 2 +/, Cu/sup 2 +/, and Zn/sup 2 +/. In the aqueous digest, the Fe/sup 3 +/ is reduced to Fe/sup 2 +/ and the Cu/sup 2 +/ is masked with S/sub 2/O/sub 3//sup 2 -/. The Fe/sup 2 +/ and Zn/sup 2 +/ are not extracted into the organic phase and do not interfere with the fluorometric method.