以乙二胺四乙酸四钠盐为配位体,五氟苄基溴为衍生剂,取土壤样品(4.0 g),石英砂(2 g),Na4-EDTA(0.2 g)和水1.0 mL混匀并放置,使其水分挥发尽后加入丙酮4 mL,300 g·L-1五氟苄基溴溶液100 μL和300 g·L-1碳酸钾溶液100 μL,进行超声衍生萃取。取上清液1.0 mL,吹氮至近干,加入正己烷1.0 mL,再次吹氮至近干,定容至1 mL,按仪器工作条件进行测定。用HP-5MS毛细管色谱柱进行分离。质谱测定中用负化学离子源。线性范围为2.5~200 μg·kg-1,检出限(3S/N)为0.34 μg·kg-1。以土壤样品为基体,用标准加入法进行回收试验,测得回收率在89.1%~106%之间,测定值的相对标准偏差(n=7)在9.9%~11%之间。

Sample of soil (4.0 g) was mixed with quartz sand (2 g), Na4-EDTA (0.2 g, as ligand) and water (1.0 mL) and the mixture was evaporated to dryness under normal temperature. Acetone (4 mL), 300 g·L-1 pentafluorobenzyl bromide solution (100 μL, as derivatizing agent) and 300 g·L-1 K2CO3 solution (100 μL, as catalyst) were added to the mixture, and extraction together with derivatization was carried out ultrasonically. The supernatant (1.0 mL) was taken and evaporated to near dryness by N2-blowing. One mL of n-hexane was added and evaporated again to near dryness by N2-blowing. The volume of the n-hexane solution was made up to 1 mL, and the GC-MS analysis was carried out as prescribed. HP-5MS capillary column was used in the chromatographic separation, and negative chemical ionization was adopted in MS analysis. Linearity range for dalapon between 2.5-200 μg·kg-1 was obtained, with detection limit (3S/N) of 0.34 μg·kg-1. Recovery was tested by standard addition method using soil sample as matrix, values of recovery found were in the range of 89.1% to 106%, with values of RSD′s (n=7) ranged from 9.9% to 11%.