Determination of Organophosphorus Pesticides in Juice and Water by Modified Continuous Sample Drop Flow Microextraction Combined with Gas Chromatography-Mass Spectrometry

In this paper, the technique of continuous sample drop flow microextraction (CSDF-ME) is developed by the addition of a narrow-necked conical vessel. In the developed technique, an organic solvent denser than water is used for the extraction of organophosphorus pesticides (OPPs) from fruit juice and river water, followed by analysis with GC-MS. Eight milliliters of the sample solution is pumped at 0.5 mL min(-1) flow rate into 12.0 mu L extraction solvent (chloroform) and placed in the narrow-necked conical vessel for extraction and pre-concentration processes. Under optimal condition, the enrichment factor (EF) and linearity are found to be in the range of 102-380 and 500.0 mu g L-1 with correlation coefficient greater than 0.98, respectively. The detection limit is in the range of 0.3-1.0 mu g L-1 and LOQ ranged from 2.0-5.0 mu g L-1. The relative standard division (RSD) of six replicate measurements for three different concentrations (i.e., 15.0, 50.0, 150.0 mu g L-1) is 3.8-8.4%, 2.6-6.0%, and 2.2-4.8%, respectively. Values of RSD% of the target pesticides at 50.0 mu g L-1 concentration levels are less than 6.0%.