Wu Fengwu, Gabryelski Wojciech, Froese Kenneth
Department of Public Health Sciences, University of Alberta, Edmonton, Canada.
Analyst. 2002 Oct;127(10):1318-23. doi: 10.1039/b204574e.
A fast headspace solid-phase microextraction gas chromatography method for micro-volume (0.1 mL) samples was optimized for the analysis of haloacetic acids (HAAs) in aqueous and biological samples. It includes liquid-liquid microextraction (LLME), derivatization of the acids to their methyl esters using sulfuric acid and methanol after evaporation, followed by headspace solid-phase microextraction with gas chromatography and electron capture detection (SPME-GC-ECD). The derivatization procedure was optimized to achieve maximum sensitivity using the following conditions: esterification for 20 min at 80 degrees C in 10 microL methanol, 10 microL sulfuric acid and 0.1 g anhydrous sodium sulfate. Multi-point standard addition method was used to determine the effect of the sample matrix by comparing with internal standard method. It was shown that the effect of the matrix for urine and blood samples in this method is insignificant. The method detection limits are in the range of 1 microg L(-1) for most of the HAAs, except for monobromoacetic acid (MBAA) (3 microg L(-1)) and for monochloroacetic acid (MCAA) (16 microg L(-1)). The optimized procedure was applied to the analysis of HAAs in water, urine and blood samples. All nine HAAs can be separated in < 13 min for biological samples and < 7 min for drinking water samples, with total sample preparation and analysis time < 50 min. Analytical uncertainty can increase dramatically as the sample volume decreases; however, similar precision was observed with our method using 0.1 mL samples as with a standard method using 40 mL samples.
一种用于微量（0.1 mL）样品的快速顶空固相微萃取气相色谱法被优化用于分析水性和生物样品中的卤乙酸（HAA）。该方法包括液液微萃取（LLME），蒸发后使用硫酸和甲醇将酸衍生化为甲酯，然后进行顶空固相微萃取结合气相色谱和电子捕获检测（SPME-GC-ECD）。衍生化程序通过以下条件进行优化以实现最大灵敏度：在80℃下于10μL甲醇、10μL硫酸和0.1 g无水硫酸钠中酯化20分钟。采用多点标准加入法通过与内标法比较来确定样品基质的影响。结果表明，该方法中尿液和血液样品的基质影响不显著。除一溴乙酸（MBAA）（3μg L⁻¹）和一氯乙酸（MCAA）（16μg L⁻¹）外，大多数HAA的方法检测限在1μg L⁻¹范围内。优化后的程序应用于水、尿液和血液样品中HAA的分析。对于生物样品，所有九种HAA可在<13分钟内分离，对于饮用水样品可在<7分钟内分离，总样品制备和分析时间<50分钟。随着样品体积减小，分析不确定度可能会急剧增加；然而，使用我们的方法分析0.1 mL样品时观察到的精密度与使用标准方法分析40 mL样品时相似。
