rapid dispersive micro-solid phase extraction using mesoporous carbon cou-2 in the analysis of cloxacillin in water

a new microextraction technique termed cou-2 dispersive micro-solid phase extraction (cou-2-d-μ-spe) has been developed. the proposed method utilized synthesized mesoporous carbons, cou-2, as sorbent for sample pretreatment in the determination of cloxacillin (clox) in water.

methods

the optimized conditions involved the use of 100 mg of cou-2 as adsorbent, 50 ml of water sample at ph 2 containing 10 % (w/v) sodium chloride in a sample tube, 1 min of extraction time, methanol as desorption solvent, and 5 min of desorption time. after extraction, cou-2 was collected on a filter and clox was desorbed with 300 µl of methanol and dried under a gentle stream of nitrogen. the extract was then reconstituted to 60 µl with distilled water.

results

under the optimized conditions, the method showed excellent detection and quantification limits for clox (0.06 and 0.17 µg l−1, respectively) with good reproducibility (relative standard deviation <8 %) for both intra- and inter-day analyses. the method provided acceptable extraction recoveries for drinking water samples in the range of 89.7–113.6 %. the extraction of blank samples indicated that both samples were free from clox contamination. the high recoveries and good precision for clox suggest that the cou-2-d-μ-spe is potentially a good alternative microextraction technique for the monitoring of pharmaceuticals in water samples.