以分光光度計法及原子吸收光譜儀法檢測劑形中Cephalexin 及Cephradine   全文下載

Spectrophotometric and Atomic Absorption Spectrometric Determination of Cephalexin and Cephradine in Dosage Forms

本論文描述兩種簡單、靈敏且具選擇性的分光光度計法及原子吸收光譜儀法，用以檢測cephalosporins 之兩種化合物—cephalexin monohydrate 及cephradine。這些步驟是依據下列原理：藥物及硫氰酸鉻銨之間產生離子對化合物，該沉澱化合物再經由分光光度計或原子吸收光譜儀程序來定量。這些方法包括：在25 ± 2° C 酸性環境下，藥物與雷氏鹽之反應。分光光度計步驟（步驟I）乃根據丙酮溶解所形成的沉澱物、體積定量完全，以及波長525 nm 下溶液相較空白組的吸光度。同樣地，原子吸收光譜儀步驟（步驟II）是在波長358.6 nm 下，透過鉻沉澱物的形成及濾紙上殘留的未反應鉻，直接或間接來定量檢測。沉澱之最適條件已被詳加研究。分光光度計法及原子吸收光譜儀法中，符合比爾定律之該藥物濃度範圍分別為0.1-1.5 mg mL-1及5-70 μg mL-1，相關係數均 ? 0.9965。對於不同劑形中特定cephalosporins之分析，步驟I 及步驟II 均呈現良好的準確度、精確度與回收率（98.90 ± 0.94 至100.15 ± 0.97），且不受添加物之干擾。

This paper describes two simple, sensitive and selective spectrophotometric and atomic absorption spectrometric (AAS) procedures for the determination of two compounds of cephalosporins (Cephalexin monohydrate and Cephradine). These procedures are based on the formation of ion-pair complexes between the drugs and ammonium reineckate. The formed precipitates are quantitatively determined either spectrophotometrically or by AAS procedures. The methods consist of reacting drugs with Reinecke’s salt in an acidic medium at a temperature of 25 ± 2°C. The spectrophotometric procedure (procedure I) is based on dissolving the formed precipitate with acetone. The volume was completed quantitatively and absorbance of the solution was measured at 525 nm against blank. Also, the AAS procedures (procedure II) are quantitatively determined directly or indirectly through the chromium precipitate formed or the residual unreacted chromium in the filtrate at 358.6 nm. The optimum conditions for precipitation have been carefully studied. Beer’s law is observed for the studied drugs in the ranges 0.1-1.5 mg mL-1 or 5-70 μg mL-1 using spectrophotometric or AAS methods, with correlation coefficients ≥ 0.9965, respectively. Both procedures I and II were accurate and precise when applied to the analysis of the cited cephalosporins in different dosage forms with good recovery percent ranged from 98.90 ± 0.94 to 100.15 ± 0.97 without interference from additives.