Thin-layer chromatographic monitoring of sonolytic degradation of surfactants in wastewaters

Abstract

This paper describes the development and validation of high-performance thin-layer chromatography (HPTLC) method for the simultaneous determination of lamivudine (LAM), tenofovir disoproxil fumarate (TDF) and efavirenz (EFV). The separation was carried out on Merck HPTLC aluminum plates precoated with silica gel G60 F254 (20 × 10 cm) with 250-μm thickness using chloroform-methanol-toluene (9:1.2:0.3, v/v) as mobile phase. HPTLC separation of the three drugs followed by densitometric measurement was carried out in the absorbance mode at 260 nm. The drugs were resolved satisfactorily with RF values of 0.20 ± 0.02, 0.61 ± 0.01 and 0.73 ± 0.02 for LAM, TDF and EFV, respectively. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.9997, 0.9991 and 0.9990 for LAM, TDF and EFV, respectively, in the concentration range of 400–800 ng spot−1 for LAM and TDF and 800–1600 ng spot−1 for EFV. The limit of detection and quantitation were 180 and 300 ng spot−1, respec...