Multi-syringe chromatography (MSC) system for the on-line solid-phase extraction and determination of hydrochlorothiazide and losartan potassium in superficial water, groundwater and wastewater outlet samples

In this paper, a combination of multi-syringe chromatography analysis technique with extraction disks sorbents for the pre-concentration and determination of hydrochlorothiazide and losartan potassium in superficial water, groundwater and wastewater outlet samples has been developed. The system developed was proved for the determination of hydrochlorothiazide and losartan potassium in spiked water samples with recoveries ranging from 95 to 118%. The method involves the on-line enrichment of the targeted analytes from spiked water samples onto a Cation-SR sorbent material. The analytes are subsequently eluted and transported to the monolithic column, Chromolith Flash RP-18e column (25 mm × 4.6 mm i.d.). The mobile phase used was 10 mM potassium dihydrogen phosphate (pH 3.0):acetonitrile:methanol (60:30:10 v/v/v), flow-rate 0.8 mL min−1. UV detection is carried out at 226 nm. Under the optimized chemical and physical variables, the detection limit for hydrochlorothiazide and losartan potassium calculated as 3Syx/b was 0.07 and 0.09 mg L−1, respectively, for a sample loading volume of 1.0 mL.