以环己烷为浮选溶剂对钾盐正浮选卤水中的十八烷胺进行溶剂浮选分离及富集,结果表明:试液pH为6,空气流量为64 mL·min-1,浮选时间为50 min时浮选效果最佳。浮选完成后,采用紫外-可见分光光度法测定环己烷中十八烷胺的含量。以溴甲酚绿为显色剂,在416.5 nm处测量吸光度,十八烷胺的质量浓度在5.00 mg·L-1以内符合朗伯-比耳定律,检出限为0.164 mg·L-1,加标回收率在95.0%~101%之间,测定值的相对标准偏差(n=8)小于2.0%。

Solvent flotation with cyclohexane was used to separate and enrich octadecylamine from brine of direct flotation of potassium salt. Optimum conditions for solvent flotation were found as follows: ① acidity of testing solution was pH 6; ② flow-rate of air was 64 mL·min-1; ③ time of flotation was 50 min. After solvent flotation, octadecylamine in cyclohexane was determined by UV-Vis Spectrophotomety at the wavelength of 416.5 nm with bromocresol green as chromogenic agent. Lambert-Beer law was obeyed for octadecylamine within 5.00 mg·L-1 and detection limit of 0.164 mg·L-1. Values of recovery obtained by standard addition method were in the range of 95.0%-101%, with RSDs (n=8) less than 2.0%.