Leblanc Y G, Gilbert R, Hubert J
Institut de recherche d'Hydro-Québec (IREQ), 1800, boulevard Lionel-Boulet, Varennes, Québec, Canada J3X 1S1, and Département de Chimie, Université de Montréal, P.O. Box 6128, Québec, Canada H3C 3J7.
Anal Chem. 1999 Jan 1;71(1):78-85. doi: 10.1021/ac9803683.
An alternative approach is described for the measurement of pentachlorophenol (PCP) and its oil solvent in wood samples by supercritical fluid extraction (SFE) and gas chromatography (GC). The determination is achieved over a single chromatographic run using postcolumn flow splitting for simultaneous ECD/FID detection of the SFE extracted species. First, PCP and oil components are quantitatively extracted from a 0.3-g wood sample using 10% MeOH/CO(2) supercritical fluid at 0.65 g/mL and 120 °C. An aliquot of the SFE solution is then mixed with 10 mL of a buffered aqueous phase at pH 9.4. After PCP is acetylated by the addition of 500 μL of acetic anhydride, it is followed by its extraction with 2.00 mL of hexane along with oil. Then, 0.5 μL of supernatant organic phase is injected into the GC for a selective and simultaneous determination of the species. The method has a linear response over 3 orders of magnitude for both species with a linear regression correlation coefficient higher than 0.98 (95% confidence limit) and an absolute detection limit of 60 ng of PCP and 80 μg of oil per 0.1-g wood sample. The precision (relative standard deviation) is 4% for PCP and 1% for oil as established for a typical average concentration sample. The accuracy of the SFE GC-ECD/FID combined technique for PCP and oil was assessed by analyzing wood samples collected from newly and in-service PCP/oil-impregnated red pine poles.
本文描述了一种通过超临界流体萃取（SFE）和气相色谱（GC）测定木材样品中五氯苯酚（PCP）及其油溶剂的替代方法。该测定通过单次色谱运行实现，采用柱后分流技术同时对SFE萃取物进行电子捕获检测器（ECD）/火焰离子化检测器（FID）检测。首先，使用10%甲醇/二氧化碳超临界流体在0.65 g/mL和120°C条件下从0.3 g木材样品中定量萃取PCP和油成分。然后，取一份SFE溶液与10 mL pH 9.4的缓冲水相混合。加入500 μL乙酸酐使PCP乙酰化后，用2.00 mL己烷与油一起萃取。接着，将0.5 μL上清有机相注入GC，以选择性地同时测定这些物质。该方法对两种物质在3个数量级范围内具有线性响应，线性回归相关系数高于0.98（95%置信限），每0.1 g木材样品中PCP的绝对检测限为60 ng，油的绝对检测限为80 μg。对于典型平均浓度样品，PCP的精密度（相对标准偏差）为4%，油的精密度为1%。通过分析从新的和在用的PCP/油浸渍红松杆上采集的木材样品，评估了SFE GC-ECD/FID联合技术对PCP和油的准确性。
