The use of solid phase reactors as the source of a catalytic solution. the indirect flow-injection spectrophotometric determination of amino acids

Abstract

A determinação indiretade aminoácidos é realizada em um sistema de injeção de fluxo utilizando-se um reator de fase sólida que contém sais cúpricos, imobilizados em esferas de resina de poliéster. Uma substância farmacêutica é forçada através do reator e os íons cúpricos liberados (complexados pela substância farmacêutica) agem como catalisadores da reação subseqüente en tre Fe(III) e tiosulfato de sódio. A curva de calibração é lin ear no intervalo de concentrações 0,1-0,3 µg L -1 para glicina, com um desvio padrão relativo de 2,3% e uma velocidade de passagem de 28 amostras por hora. Foi analisada a influência de substâncias estranhas e o método foi aplicado à determinação de glicina em duas formulações farmacêuticas diferentes.The in di rect de ter mi na tion of amino ac ids is car ried out in a flow-injection as sem bly by means of a solid-phase re ac tor con tain ing cu pric salts, im mo bi lized in poly es ter resin be ads. A phar ma ceu ti cal sub stance is forced through the re ac tor and the re leased cu pric ions (compl exed by the phar ma ceu ti cal sub stance) act as a cat a lyst for the sub se quent re ac tion be tween Fe(III) and so dium thiosulfate. The cal i bra tion graph is lin ear over the range 0.1-3.0 µg mL -1 glycine, the RSD was 2.3%, and the sam ple through put was 28 h -1 . The in flu ence of for eign sub stances was stud ied and the method was ap plied to the de ter mi na tion of glycine in two dif fer ent pha rma ceu ti cal for mu la tions.

Determination of cyanide by a flow injection analysis-atomic absorption spectrometric method

“…5 A comparative study dealing with different off-line detection systems (spectrophotometric, atomic absorption and polarographic) after formation of the stable tetracyanonickelate anion complex has been reported. 6 The use of solid-phase reactors in FIA assemblies has been demonstrated to be useful for the in situ preparation of unstable reagents 7 or very dilute solutions 8 due to redox characteristics or, as is the present case, the instability of silver ion solutions to room light. Other advantages of solid-phase reactors over their counterparts in homogeneous systems have been described.…”

A Comparative Study of AgX (X = Cl−, Br−, I− and N3−) Solid-Phase Reactors for Flow-Injection Determination of Cyanide in Electroplating Wastewater

“…[26][27][28][29] The use of solid-phase reactors in FIA assemblies has been demonstrated to be useful for the in situ preparation of unstable reagents, 30 or very dilute solutions 31 due to the redox characteristics, or as in the present case, the instability of silver ion solutions to room light. Other advantages of solid-phase reactors over their counterparts in homogeneous systems have been described.…”