称取试样约5 g （精确至0.01 g），加入1.000 mg·L^-1甲萘威-D7同位素内标溶液50 μL，加入适量水（肉样加水1.5 mL，肉制品加水3 mL），加40 mL丙酮，均质1 min，加氯化钠6 g，充分摇匀，再加30 mL石油醚，振摇30 min，静置30 min。取有机层上清液，经无水硫酸钠过滤，旋转蒸发浓缩至约1 mL，加2 mL乙酸乙酯-环己烷（1+1）混合液，再浓缩至约1 mL，如此重复3次。用乙酸乙酯-环己烷（1+1）溶液定容至10.0 mL，经0.22 μm滤膜过滤，进行凝胶色谱（GPC）净化。GPC条件如下：Bio Beads S-X3凝胶色谱净化柱（400 mm×30 mm），乙酸乙酯-环己烷（1+1）混合液为流动相，馏分收集段10.0~15.0 min，在线浓缩加热温度45℃，真空度2.0×10⁴Pa。以乙腈为替换溶剂替换两次后将净化液定容至1.0 mL，进行液相色谱-串联质谱分析。采用HSS T3色谱柱（100 mm×2.1 mm，1.7 μm）进行分离，以0.1%（体积分数）甲酸溶液-乙腈（6+4）为流动相，质谱分析中采用电喷雾正离子源和多反应监测模式。甲萘威的质量浓度在0.010~0.500 mg·L^-1内和其峰面积与内标峰面积之比呈线性关系，测定下限（10S/N）为0.005 mg·kg^-1。加标回收率在81.0%~105%之间，测定值的相对标准偏差（n=6）在3.8%~16%之间。

About 5 g (accurate to 0.01 g) of the sample and 50 μL of 1.000 mg·L^-1 carbaryl-D7 isotope internal standard solution were added into appropriate amount of water (1.5 mL of water for the meat sample, 3 mL of water for meat products). Then 40 mL of acetone was added and the mixture was homogenized for 1 min. 6 g of sodium chloride was added and the mixture was shaked well. 30 mL of petroleum ether was added and the mixture was shaked for 30 min and let stand for 30 min. The organic layer supernatant was taken, filtered through anhydrous sodium sulfate, and concentrated to about 1 mL by rotary evaporation. 2 mL of ethyl acetate-cyclohexane (1+1) solution was added, and the mixture was concentrated to about 1 mL by rotary evaporation. After the above operation was repeated 3 times, the solution was made to 10.0 mL with ethyl acetate-cyclohexane (1+1) solution, filtered through a 0.22 μm filter membrane, and cleaned up by gel permeation chromatography (GPC) under conditions as follow: Bio Beads S-X3 gel chromatographic column (400 mm×30 mm) was used as stationary phase, with ethyl acetate-cyclohexane (1+1) solution as mobile phase; fraction collection section was 10.0-15.0 min; on-line concentration heating temperature was 45 ℃; degree of vacuum was 2.0×10⁴Pa. After solvent replacement was carried out 2 times with acetonitrile as replacement solvent, the purified solution was made up to to 1.0 mL, and analyzed by liquid chromatography-tandem mass spectrometry. Separation was performed on a HSS T3 column (100 mm×2.1 mm, 1.7 μm) with a mixture of 0.1% (volume fraction) formic acid solution-acetonitrile (6+4) as mobile phase. Electrospray ionization source and multiple reaction mornitoring mode were used in mass spectrometry. Linear relationship was found between the ratio of peak area of carbaryl to peak area of internal standard with the mass concentration of carbaryl in the range of 0.010-0.500 mg·L^-1. The lower limit of determination (10S/N) was 0.005 mg·kg^-1. Values of recovery obtained by standard addition method were in the range of 81.0%-105 %, the relative standard deviations (n=6) of the measured values were between 3.8% and 16%.