No abstract

The development and validation of an analytical method for the simultaneous determination of Dextromethorphan Hydrobromide, Chlorpheniramine Maleate, and Potassium Sorbate in cough syrup using the High-Performance Liquid Chromatography (HPLC) method have been conducted. The determination was carried out on the simulation sample consisting of three substances and prepared five different concentrations, with three replications for each concentration. The optimum HPLC conditions were obtained using the C18 column, with UV detection at 230 nm The mobile phase of acetonitrile & phosphate buffer pH 2.5 (containing sodium-heptane sulfonate as ion-pair), with a gradient elution system, at a 1 mL/minute, while the flow rate column temperature is set at 35oC. The results showed that the method has met the parameters set in the validation test with the recovery ranged from 98% - 102%, the precision test results (RSD) < 2%, and the linearity (r) ≥ 0.98. The method obtained is quite selective by confirmed identity with the maximum wavelength scanning of each analyte peak by PDA detector. The limit of detection (LoD) for Dextromethorphan-HBr, Chlorpheniramine maleate and Potassium sorbate were 3.13 µg/mL, 0.94 µg/mL and 0.12 µg/mL respectively and the limit of quantitation (LoQ) were 9.49 µg/mL, 2.85 µg/mL and 0.38 µg/mL respectively.

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Neodymium, Praseodymium, Cerium, and ABSTRAKNeodimium, Praseodimium, Serium, dan Lantanum merupakan unsur tanah jarang dengan kadar tinggi yang terdapat dalam monasit dan senotim. Sampel yang digunakan dalam penelitian ini adalah pasir monasit dari PT Timah Bangka yang diperoleh melalui hasil Dowa Mining. Penentuan dan pemisahan unsur tanah jarang ini dilakukan dengan metode KCKT pertukaran ion menggunakan kolom penukar ion Supelcosil LC-SCX panjang kolom 25 cm, diameter 4,6 mm, dan ukuran partikel 5 µm dengan menggunakan detektor konduktometer jenis Waters 432. Kondisi optimum pemisahan unsur tanah jarang: menggunakan larutan etilendiamin 1,50 mM dan asam tartrat 2,00 mM sebagai fasa gerak dan pengompleks pada pH 4,5 dengan kecepatan alir 0,8 mL/menit dan volume sampel 10 µL. Hasil penelitian menunjukkan bahwa metode KCKT pertukaran ion dapat digunakan untuk memisahkan dan menentukan kandungan Neodimium, Praseodimium, Serium, dan Lantanum. Kromatogram campuran dari keempat unsur tanah jarang yang diperoleh dapat terpisah dengan baik, hal ini dapat dilihat dari resolusinya (R) berkisar 2 sampai 4 pada konsentrasi 100 ppm untuk Neodimium, Praseodimium, Serium, dan Lantanum dengan waktu retensi berturut-turut 9,66; 10,87; 13,42; 16,29 menit. Kandungan Neodimium, Praseodimium, Serium, dan Lantanum