An evaluation of solid‐phase microextraction for analysis of volatile organic compounds in drinking water
An evaluation of solid‐phase microextraction for analysis of volatile organic compounds in drinking water
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固相微萃取分析饮用水中挥发性有机化合物的评价
DOI：
10.1002/jhrc.1240181002
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
J. Madsen
中科院分区：
文献类型：
--
作者：
T. Nilsson;F. Pelusio;L. Montanarella;B. Larsen;S. Facchetti;J. Madsen
将固相微萃取(SPME)技术应用于饮用水中60种挥发性有机化合物(VOCs)的定量分析。在完全搅拌和非搅拌样品的理论曲线之间，可以找到在20℃、50℃和80℃时VOCs在纤维涂层和强化水之间分配的平衡曲线。影响SPME纤维涂层吸附量的两个重要因素是萃取时间和纤维涂层/水分分配系数KFW。两者都取决于样品温度，但以一种相反的方式：升高温度缩短了平衡时间，特别是对于较重的VOCs，但也导致KFW值较低，从而降低了方法的灵敏度。测定了33种VOCs在40℃、60℃和80℃时的KFW值，并计算了吸附热-ΔH。吸附的性质是放热的，这解释了该方法的灵敏度随温度的升高而降低的原因。检出限一般在20 ng/L至200 ng/L之间，但存在检测困难的极轻挥发性有机物除外。对于所有挥发性有机化合物，其线性范围从实际检测的最低浓度扩展到至少5 mg/L。当使用内标时，精密度为3%的平均标准偏差，对于大多数定量常规分析是令人满意的。通过水/顶空/纤维涂层之间的耦合平衡，将固相微萃取应用于饮用水的顶空分析。研究表明，HS-SPME的平衡时间比直接从水中的SPME短，且灵敏度相同，但VOCs非常轻。对被1，1，1-三氯乙烷、三氯乙烯和四氯乙烯污染的低μg/L水厂水样进行了分析。固相微萃取的结果与吹扫捕集的结果似乎有合理的一致性。说明固相微萃取技术在饮用水分析中具有很大的应用潜力。
Solid-phase microextraction (SPME) has been applied to the quantitative analysis of 60 volatile organic compounds (VOCs) in drinking water. Equilibration curves for the partitioning of the VOCs between the fiber coating and fortified water obtained at 20, 50, and 80 °C are found between the theoretical curves for completely agitated and non-agitated samples. Two important factors for the amount adsorbed by the SPME fiber coating are the extraction time and the fiber coating/water distribution coefficient, KFW. Both depend on the sample temperature, but in a counteracting manner: Increasing the temperature shortened the equilibration times, especially for the heavier VOCs, but also lead to lower KFW values, and consequently a lower sensitivity of the method. KFW values are determined for 33 of the VOCs at 40, 60, and 80°C and the heats of adsorption,–ΔH, are calculated. The nature of the adsorption is found to be exothermic which explains the decreasing sensitivity of the method with increasing temperature. Detection limits were typically from 20 ng/l to 200 ng/l, except for the very light VOCs with which detection difficulties were encountered. For all of the VOCs the linear range extended from the lowest concentration at which they were actually detected to at least 5 mg/l. The precision, 3% average standard deviation when an internal standard was used, was satisfactory for most quantitative routine analysis. SPME was also applied to head-space (HS) analysis of drinking water through the coupled equilibrium between water/head-space/fiber coating. HS-SPME is demonstrated to have shorter equilibration times than SPME directly from the water and equal sensitivities, except for the very light VOCs. Water samples from a drinking water plant contaminated in the low μg/l range with 1,1,1-trichloroethane, trichloroethene and tetrachloroethene were analyzed. There seems to be a reasonable agreement between results obtained by SPME and purge & trap. It is concluded that SPME has a great potential for drinking water analysis.