Ultrasonic assisted magnetic dispersive solid phase microextraction for preconcentration of two nonsteroidal anti-inflammatory drugs in real water, biological and milk samples employing an experimental design

Abstract

A novel, simple and sensitive ultrasonic assisted magnetic dispersive solid phase microextraction coupled with high performance liquid chromatography was developed for preconcentration and measurement of meloxicam (MEL) and piroxicam (PIR). An efficient and new encapsulated magnetic SPME sorbent, Fe3O4/NiO@SiO2-OP2O5H, was prepared based on co-precipitation and sol-gel procedures for the extraction of the analytes. Several effective factors in the extraction and determination of MEL and PIR such as pH of sample solution, amount of sorbent, sample solution volume, type and volume of acceptor phase, dispersion time, extraction time and desorption time were thoroughly studied and optimized using a simple experimental design with a small number of experimental runs. Under the optimum conditions, the standard curves ranged from 0.3 to 180 and 0.3 to 160 ng mL−1 for MEL and PIR in the water samples with an R-squared of 0.9949 and 0.9941, respectively. Intra and inter day relative standard deviations (n = 5) for MEL and PIR were <5.7 and 7.6%, respectively. This method was successfully applied to determine MEL and PIR in the well, tap and river water, human urine and milk samples, and the average recoveries in the real samples were >87.9% for the analytes. These results indicate that the proposed method is a suitable procedure for the determination of MEL and PIR in various real samples.