내부표준법과 외부표준법에 따른 검량선 방법의 비교분석

Abstract

In this study, the internal standard method was compared with the external standard method in the determination of organic phosphorus pesticides. Also, We compared the internal standard methods of volume(w/v) with weight(w/w). Analyte was parathion and internal standard was malathion. Calibration curve was drawn with parathion at the final concentration of 0.5 μg/mL, 1.0 μg/mL, 2.5 μg/mL in the external standard method. The internal standard method of volume was in the same way. However, it was fortified with 10 μg internal standard (malathion), respectively, and was dissolved in hexane. After dissolving, total volume of the sample was 10 mL. In the case of the internal standard method of weight, calibration curve was completed with parathion at the final weight of 5 μg, 10 μg, 25 μg. It was fortified with 10 μg internal standard (malathion) respectively, and dissolved in about 10 mL hexane. But it was not important to set the volume exactly. 10 μg of parathion and malathion were spiked into 500 mL deionized water and analyzed with a GC-NPD (Gas Chromatograph-Nitrogen Phosphorus Detector). Result obtained with the external standard method was 0.0134 μg/ mL (RSD 1.437), the internal standard method with volume basis was 0.0143 μg/mL (RSD 1.376) and the internal standard method with weight basis was 0.0146 μg/mL (RSD 1.316). Accuracies of the external standard method, of the internal standard method with volume basis and with weight basis were 67%, 72% and 73%, respectively. Thus the internal standard method with weight basis can determine pesticides more accurately and precisely than the external standard method and is more convenient than the internal standard method with volume basis.