Recebido em 7/3/09; aceito em 7/7/09; publicado na web em 8/1/10 SPECTROPHOTOMETRIC OLANZAPINE DETERMINATION IN PHARMACEUTICAL FORMULATIONS: METHOD DEVELOPMENT AND VALIDATION. Spectrophotometric methods of zero order, first and second derived order had been developed for olanzapine determination in tablets using ethanol and isopropanol as solvent. The two solvents revealed to be adequate. For the three methods the calibration curve coefficient of correlation had been greater than 0. , in isopropanol. The inter-day precision was inferior to 1.1 and 1.9 mg L -1 for ethanol and isopropanol, respectively. The average recoveries varied from 98 to 101%, in ethanol and 99 to 103% in isopropanol.
A procedure is proposed for Pb determination in medicinal plants by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) using direct solid sampling. Among Pd(NO(3))(2), Pd/Mg(NO(3))(2), NH(4)H(2)PO(4) and the W-coated platform tested as chemical modifiers, Pd(NO(3))(2) presented the best performance. Calibration plots (10-1000 pg Pb) with regression coefficients better than 0.999 were typically obtained. Accuracy was checked for Pb determination in five plant certified reference materials. Results were in agreement with reference values at a 95% confidence level (paired t-test). Medicinal plant samples were analyzed by the proposed procedure and line-source GF AAS using slurry sampling as a comparative technique. The RSD was 10% (n=3) for a sample containing 0.88 μg g(-1) Pb. The limit of quantification (dry mass) was 0.024 μg g(-1). The contents of Pb in medicinal plant samples varied in the 0.30-1.94 μg g(-1) range.
chama é feita frequentemente em espectrômetros com fontes de radiação discretas (LS FAAS) [3]. Esta determinação é uma tarefa simples, contudo trabalhosa e morosa porque requer otimizações instrumental e operacional específicas para cada elemento, tais como: a troca e o condicionamento das fontes de radiação, os espaços temporais relativamente longos entre calibrações, os ajustes da diluição da amostra aos respectivos intervalos lineares das curvas analíticas que consomem tempo e aumentam os custos analíticos. Estes aspectos negativos podem ser minimizados se vários elementos puderem ser determinados conjuntamente numa única alíquota da amostra [4]. Apesar dos teores de Mg em tecidos vegetais serem inferiores aos usualmente encontrados para Ca e K [5], a utilização da linha atômica principal ou secundária do Mg não permite determiná-lo na mesma alíquota de amostra utilizada para determinar Ca e K, uma vez que os limites superiores de resposta linear são baixos (0,5 e 10 mg L -1 Mg, respectivamente), exig-
INTRODUÇÃOConhecer a composição de plantas medicinais é uma forma de garantir a população brasileira o acesso seguro e o uso racional dessas plantas, promover o uso sustentável da biodiversidade e desenvolver a cadeia produtiva nacional. As plantas medicinais podem apresentar alto valor nutritivo e a determinação do teor total de um elemento é relevante [1]. O estabelecimento de métodos de análise desta classe de plantas voltados a um controle de qualidade eficiente, visando minimizar a probabilidade de ocorrência de problemas toxicológicos, afigura-se como promissor. Entre as técni-cas analíticas, a espectrometria de absorção atômica [2] ocupa um espaço importante no campo das análises químicas elementares.A determinação de Ca, K e Mg em plantas medicinais por espectrometria de absorção atômica em A simple and rugged method to determine Ca, K and Mg in a single aliquot of medicinal plants by high-resolution continuum source flame atomic absorption spectrometry is proposed. Secondary lines for Ca (239.856 nm) and K (404.414 nm), and the alternate line measured at wing of the secondary line for Mg at 202.588 nm allowed calibration within the 20 -500 mg L -1 Ca and K, and 1.0 -80 mg L -1 Mg. Twenty samples and three plant certified materials were analyzed. Results were in agreement at a 95% confidence level with reference values. Limits of detection were 2.4 mg L -1 Ca, 1.9 mg L -1 K and 0.3 mg L -1 Mg. The RSD (n=12) were ≤ 5.1% and recoveries were between 83 and 108% for all analytes.
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