Research on the Determination of Metribuzin from Soils by Gas Chromatography−Nitrogen Chemiluminescence Detector(GC−NCD)

The nitrogen chemiluminescence detector(NCD) by coupling gas chromatography(GC) was selected in this experiment. An efficient, high sensitivity and low cost method was established to determine metribuzin from soils. The result proved that soil samples were extracted with acetonitrile/water mixture(V/V, 3∶1) without sample purification and quantified by blank matrix external standard method. The method also was confirmed by GC-MS. With the optimized conditions, highly correlated linear relationships were achieved between the peak area and concentration on the target compounds. The correlation coefficient of standard curve equation is 0.999 9. At the spiked levels of 0.05 mg/kg, 0.1 mg/kg, 0.5 mg/kg in blank soil samples, the average recoveries were 90%–116%, the relative standard deviations were 2.38%–7.76%. The limits of detection(LOD) was 0.006 mg/kg, the limits of quantification(LOQ) was 0.05 mg/kg. The obtained data are comparable to the GC−MS detection results, and the detector can be accurately quantified in the case of matrix interference. The method had simple pre-treatment and reliable data, the stable instrument is maintained easily. The requirement could be met for the detection of metribuzin residue in soils.