液-液萃取气相色谱法测定四氯化钛水解体系中痕量四氯化碳的不同萃取剂萃取能力对比

比较了液-液萃取气相色谱测定精四氯化钛水解样品中四氯化碳方法中使用的庚烷、正己烷、正辛烷、异辛烷4种萃取剂对痕量四氯化碳的萃取效果。结果表明:4种萃取剂对四氯化碳都有较好的响应, 色谱图上的峰位和峰形都较好, 而且四氯化钛中三氯甲烷、一氯乙酰氯、三氯乙酰氯共存杂质对四氯化碳的测定没有干扰。对于庚烷、正己烷、正辛烷、异辛烷, 校准曲线的线性相关系数分别为0.990 8、0.997 2、0.998 7、0.999 5, 检出限分别为0.003 2、0.001 5、0.004 4、0.001 1, 样品加标平均回收率分别为95.4%、98.8%、96.4%、99.6%, 相对标准偏差分别为2.6%、4.0%、4.6%、1.6%。因此, 4种萃取剂对四氯化碳都有较好的萃取能力, 但异辛烷的萃取能力最强, 稳定性也较好。

Comparison of extraction abilities of different extractants used in liquid-liquid extraction and gas chromatography for determination of trace carbon tetrachloride in hydrolytic system of titanium tetrachloride

The extraction effects of four extractants liking heptane, n-hexane, n-octane and iso-octane used for the extraction of trace carbon tetrachloride in the determination trace carbon tetrachloride in the hydrolytic sample of refined titanium tetrachloride by liquid-liquid extraction gas chromatography were compared. The four extractants all exhibited fine response to carbon tetrachloride and gave good peak positions and peak shapes in the chromatograms. The coexisting impurities including chloroform, chloroacetyl chloride and trichloroacetyl chloride in titanium tetrachloride didn’t interfere in the determination of carbon tetrachloride.For heptane, n-hexane, n-octane and iso-octane, the linear correlation coefficients of the calibration curves were 0.990 8, 0.997 2, 0.998 7 and 0.999 5, the detection limits were 0.003 2, 0.001 5, 0.004 4 and 0.001 1, the sample standard average recoveries were 95.4 %, 98.8 %, 96.4 % and 99.6 % and the relative standard deviations were 2.6 %, 4.0 %, 4.6 % and 1.6 %, respectively. Thus, the four extractants all had satisfactory extraction capacity for carbon tetrachloride, but iso-octane had the best extraction capacity and better stability.