Direct determination of s-carboxymethyl-l-cysteine in syrups by reversed-phase high-performance liquid chromatography.
A simple reversed-phase high-performance liquid chromatography method was developed for the determination of s-carboxymethyl-l-cysteine in syrup preparations. The experiments were performed without specific sample pre-treatment. The LC conditions used were acetonitrile-10 mM sodium dihydrogenphosphate buffer, pH 2.0 (1:99, v/v) on a C(18) Inersil column with a flow rate of 1.5 ml/min. Ultraviolet detection was carried out at 240 nm. The method showed excellent linearity (r(2)>0.9998) over the concentration range tested (0.8-25.6 mg/ml) with good precision and accuracy (%R.S.D. 0.7%). Recoveries were good (>99%) with a limit of detection and limit of quantitation of 0.1 and 0.8 mg/ml. Other compositions in the syrup vehicle did not interfere the analysis of s-carboxymethyl-l-cysteine.
Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudhaya Road, Rajathevee, Bangkok 10400, Thailand. lleena65@aol.com
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D002138:Calibration; D002233:Carbocysteine / Q000032:analysis*; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D005100:Expectorants / Q000032:analysis; D012015:Reference Standards; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet
D005100:Expectorants; D002233:Carbocysteine