Ionic Liquid-Based Ultrasound-Assisted Emulsification Microextraction Coupled with HPLC for Simultaneous Determination of Glucocorticoids and Sex Hormones in Cosmetics

An effective and environmentally friendly method based on ionic liquid-based ultrasound-assisted emulsification microextraction(IL-USAEME) and high performance liquid chromatography (HPLC) has been developed for the determination of nine hormones including three glucocorticoids, one androgen and five progestogens in cosmetics. Several factors that affect the extraction efficiency, such as the kinds and volume of ionic liquid, salt concentration, ultrasonic power and time, and centrifugation time were investigated and optimized. Under the optimum extraction condition, the recoveries of analytes ranged from 85.97% to 108.84% except prednisolone (62.30%). The intraday and interday precision was below 2.51% and 3.30%, respectively.

Ultrasound-Assisted Emulsification Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Droplet for Separation of Trace Gold Prior to Flame Atomic Absorption Spectroscopy Determination

In the present work, a ultrasound-assisted emulsification dispersive liquid-liquid microextraction based on solidification of floating organic droplet method has been developed as a sample preparation method prior to flame atomic absorption spectrometry determination of trace amounts of gold in the standard, wastewater and river water samples. In the proposed method, 1-dodecanol and 5-(4-dimethylamino-benzylidene) were used as extraction solvent and chelating agent, respectively. Several factors that may be affected on the ex-traction process, such as type and volume of the extraction solvent, ionic strength, pH of the aqueous solu-tion, extraction temperature and extraction time were studied and optimized. Under the best experimental conditions, the calibration curve exhibited linearity over the range of 8.0 ng●mL-1- 3.0 μg●mL-1 with a correlation coefficient of 0.9978 and detection limit based on three times the standard deviation of the blank signal was 1.5 ng●mL-1. Eight replicate determinations of 0.2 and 1.0 μg●mL-1 of gold gave a mean absorbance of 0.051 and 0.253 with relative standard deviations of ±2.3% and ±1.5%, respectively. Finally, the developed method was successfully applied to the extraction and determination of gold ions in a silica ore, wastewater, river water and standard samples and satisfactory results were obtained.

Ultrasound-assisted emulsification solidified floating organic drop microextraction for the determination of trace amounts of copper in water samples

A simple and efficient liquid-phase microextraction(LPME)technique was developed using ultrasound-assisted emulsification solidified floating organic drop microextraction(USAE-SFODME)combined with flame atomic absorption spectrometry,for the extraction and determination of trace copper in water samples.1-(2-Pyridylazo)-2-naphthol(PAN)was used as chelating agent.Microextraction efficiency factors(including extraction solvent type,extraction volume,time,temperature,and pH),the amount of the chelating agent,and salt effect were investigated and optimized.Under the optimum extraction conditions,figures of merit of the proposed method were evaluated.The calibration graph was linear in the range of 20–600 mg·L^(–1)with a detection limit of 0.76 mg·L^(–1).The relative standard deviation(R.S.D)for ten replicate measurements of 20 and 400 mg·L^(–1)of copper was 3.83%and 2.65%,respectively.Finally,the proposed method was applied to tap water,river water,and sea water,and accuracy was assessed through the analysis of certified reference water or recovery experiments.

不锈钢丝SPME-HPLC联用测定水样中的芳香烃

在修饰过的不锈钢丝表面涂覆（苯乙烯-二乙烯基苯）高内相乳液，制作了不锈钢丝固相微萃取（ SPME ）萃取头，与高效液相色谱（ HPLC）联用测定了环境水样中的芳香烃。系统考察了萃取时间及解吸时间等实验条件对萃取效率的影响，建立了测定环境水样中芳香烃的SPME-HPLC方法。实验结果表明，方法的柱内（ n＝6）和柱间（ n＝3）精密度（ RSD ）分别小于6.5％和8.6％，实际样品的加标回收率在84.4％～95.4％之间；3种芳香烃化合物的线性范围为5～200μg/L，线性相关系数r＞0.9960，检出限在0.09～0.20μg/L之间。该方法快速、灵敏、简便，适用于快速分析环境水样中的芳香烃。

超声辅助分散乳液微萃取/高效液相色谱法同时测定辣椒粉中的5种染色剂

建立了超声辅助分散乳液微萃取技术结合高效液相色谱法（HPLC）同时测定辣椒粉中对位红、苏丹红Ⅰ、苏丹红Ⅱ、苏丹红Ⅲ、苏丹红Ⅳ的方法。考察了萃取剂的种类及其体积、分散剂体积分数、盐效应、p H值、萃取时间和离心时间等因素对萃取效果的影响,确定最佳萃取条件为：0.75 m L环己烷为萃取剂,10%乙腈为分散剂,振荡1 min,以6 000 r/min离心5 min,吸取萃取相过0.22μm有机尼龙滤头,进行HPLC分析。最优条件下,在辣椒粉中分别添加50,250,1 000 ng/g 3个水平的染色剂,测得市售散装、包装辣椒粉中5种染色剂的加标回收率为82%~114%,相对标准偏差（RSD,n=3）为0.7%~8.8%。所有目标化合物在25~5 000 ng/m L范围内线性良好,相关系数（r2）均不小于0.998 9;检出限为1~11 ng/m L。本方法具有简单快捷、灵敏准确等特点,满足辣椒粉中5种染色剂检测的要求。

超声辅助乳化液液微萃取-高效液相色谱法测定水中双酚A

建立了超声辅助乳化液液微萃取-高效液相色谱法测定水中双酚A的方法。优化了影响样品前处理的实验条件,包括萃取剂种类和用量、超声时间、样品溶液pH、离子强度等。在最佳实验条件下,方法的线性范围为5~1 000 ng/mL(r>0.999),检出限为0.31 ng/mL,重现性以日内和日间重复测定的相对标准偏差表示分别为2.38%和5.94%,实际样品的加标回收率为89.5%~103.1%。该实验方法成功应用于自来水、水库水、矿泉水、桶装水等实际水样品中双酚A含量的测定。

超声辅助乳化液液微萃取-高效液相色谱法测定水中邻苯二甲酸酯

目的:将超声辅助萃取与液液微萃取技术结合,建立水中邻苯二甲酸酯的高效液相色谱测定方法。方法:对水样的超声萃取条件和液液微萃取条件进行优化,采用高效液相色谱测定。结果:在0μg/ml～6.0μg/ml范围内线性关系良好r,>0.999;三种邻苯二甲酸酯检出限为0.2μg/L;水样中加标回收率为88.4%～105.4%,相对标准偏差在3.1%～6.8%。结论:本方法快速、准确适用于水中邻苯二甲酸酯的浓度测定。

高内相乳液固相微萃取联用HPLC检测水样中芳香烃

应用一种新型的高内相乳液固相微萃取的样品预处理方法,然后与高效液相色谱法联用检测环境水样中的苯、甲苯、乙苯。为确保试验的准确科学,对萃取时间、萃取溶剂、解吸时间等条件进行了优化。结果表明,3种物质在10~100μg/L范围内具有良好线性,检出限为93~241 ng/L,样品的添加回收率为86.4%~95.5%,相对标准偏差为3.1%~5.8%。该法操作简便、快速、灵敏,适用于快速分析环境水样中的痕量芳香烃。