USE OF THE ATOMIC ABSORPTION SPECTROMETER FOR THE DETERMINATION OF METHPHORMINE AND RANITIDINE CHLORIDRATES IN MEDICINES

The utilization of atomic absorption spectrometer for metformin (MET) and ranitidine (RAN) chlorohydrates determination in medicines is proposed. The spectral lines of nickel and aluminum at 232.0 and 308.2 nm were selected for MET and RAN absorbance monitoring, respectively. The results were compared to those obtained by molecular absorption spectrometry at ultraviolet range (spectrophotometry) and condutometric titration. The figures of merit obtained were adequate for MET and RAN determination in medicines. The limit of detection (LOD) of 0.01 mg L-1 obtained for MET and RAN, were similar and even lowers than those obtained by spectrophotometry and comparable with those found in the literature. The precision evaluated by relative standard deviation (RSD) was lower than 6%. The analytical application shows that in the analyzed samples the MET and RAN concentrations were in agreement with specified value in the label and the limits required by Brazilian legislation.

本研究提出采用原子吸收光谱仪（atomic absorption spectrometer）测定药物中的盐酸二甲双胍（metformin, MET）与盐酸雷尼替丁（ranitidine, RAN）含量。分别选取镍（nickel）在232.0 nm、铝（aluminum）在308.2 nm处的谱线作为二甲双胍与雷尼替丁的吸光度监测波长。将该方法的测定结果与紫外区分子吸收光谱法（molecular absorption spectrometry at ultraviolet range，即分光光度法（spectrophotometry））以及电导滴定法（conductometric titration）的测定结果进行对比。所得分析性能指标（figures of merit）足以满足药物中二甲双胍与雷尼替丁的含量测定需求。二甲双胍与雷尼替丁的检出限（limit of detection, LOD）均为0.01 mg·L⁻¹，二者检出限相近，且较分光光度法更低，同时与文献报道值相当。以相对标准偏差（relative standard deviation, RSD）评价的精密度均低于6%。分析应用结果表明，所检测样品中二甲双胍与雷尼替丁的含量与标签标注值一致，且符合巴西法规规定的限量要求。