ABSTRACT
RESUMO Este trabalho descreveu e comparou quatro estudos entre si que utilizaram métodos automáticos em fluxo com detecção espectrofotométrica e a reação de oxidação do diclofenaco para determinar diclofenaco em formulações farmacêuticas e fluidos corporais. Para isso, utilizamos os seguintes artigos: Versatility of a multicommuted flow system in the spectrometric determination of three analytes, Sequential injection spectrophotometric method for the assay of anti-inflammatory diclofenac sodium in pharmaceutical preparations, Screening of conditions controlling spectrophotometric sequential injection analysis e Sequential injection spectrophotometric determination of diclofenac in urine and pharmaceutical formulations e detalhamos as metodologias empregadas, os resultados, conclusões obtidas e comparamos entre eles os limites de detecção, desvio padrão relativo e a frequência analítica. Os resultados mostraram diferenças significativas entre métodos empregados e a utilização do Sistema automático do tipo Análise por Injeção Sequencial, apesar deste possuir menor frequência analítica.
SUMMARY This study described and compared four studies that used automatic flow methods with spectrophotometric detection and the oxidation reaction of diclofenac to determine diclofenac in pharmaceutical formulations and body fluids. For this, the following articles were used: Versatility of a multicommuted flow system in the spectrometric determination of three analytes, Sequential injection spectrophotometric method for the assay of anti-inflammatory diclofenac sodium in pharmaceutical preparations, Screening of conditions controlling spectrophotometric sequential injection analysis and Sequential injection spectrophotometric determination of diclofenac in urine and pharmaceutical formulations and we detail the methodologies used, the results, the conclusions obtained and compare the limits of detection, relative standard deviation and analytical frequency. The results showed significant differences between the employed methods and the use of the Automatic System of the Sequential Injection Analysis type, although this one has a lower analytical frequency.
ABSTRACT
A cadmium column reduction-azo dyes spectrophotometric method based on micro sequential injection lab-on-valve was established for the determination of total nitrogen in seawater. The experimental parameters were optimized, and the interference experiment was carried out. The results showed that the interference of the main components and salinity in sea water could be eliminated by using a series of standard solution prepared by national standard seawater with certain salinity. The concentration of total nitrogen in seawater was linear with the absorbance in the range of 0 . 03-1 . 00 mg/L with a correlation coefficient of 0. 9993. When determining the national standard seawater at nitrogen concentration of 0. 20 mg/L, the relative standard deviation (RSD) was 4. 9%, the detection limit was 0. 010 mg/L, and the recoveries were 99. 5%-101 . 1%. There were not significance differences between the results of this method and national standard method in the t-test analysis. The method is suitable for the determination of total nitrogen in seawater.
ABSTRACT
A fluorescence quenching method was established for the determination of H2 S in intestinal perfusate by optical fiber sensing technology combined with micro sequential injection lab_on_valve (μSIA_lov). In the experiment, 100 μL of 0. 1 mol/L NaOH was used as the carrier, and 50 μL of 5. 0×10-5 mol/L fluorescein mercury and 50 μL of sample were selected for the determination. The detection flow rate at the flowcell was 25 μL/s. According to H2 S quenching fluorescence at 521 nm, the concentration of H2 S in the sample was determined. The detected concentration range of H2S was 5. 0×10-6-8. 0×10-5 mol/L, and the detection limit was 5. 4×10-7 mol/L. Detection result of H2S in intestinal perfusion was 3. 8×10-5 mol/L with 3. 1% RSD (n=3). This method can be used for the determination of H2S effectively in the samples, which lay the foundation for real_time online measurement of H2 S in biological samples.
ABSTRACT
An iodine analysis instrument with sequential injection of urine samples was developed. A method for measurement of urine iodine was also developed by combining sequential injection and catalysis kinetics,and making use of catalysis facilitation of the iodine in the redox reaction of As~(3+) and Ce~(4+) . The sequential injection and stopped-flow stabilization determination were made possible by the program-controlled injector with controlled flow rate and the 16-hole program-controlled selection valves. The arsenic-cerium reaction with iodine-catalyzed at constant temperature state might proceed with the constant temperature flow cell. Using the syringes with program-controlled velocity,pushing and suction,Using the digital connected circuit and micro-iodine determination software,the reaction temperature of (32.0±0.1)℃,injection time of 45 s,stabilization time of 60 s,detection time of 20 s,injection volume of 400μL,linear range of 15 -600μg/L,detecting limitation of 5.01 μg/L(n=11) and recovery rate of 94. 1 % - 105. 1 % were obtained. With this method,the detecting result of the National Standard Reference (GBW09109 and GBW09110) materials was within a given standard range. Through this method,the detecting results had no significant differences comparing with those by standard method of National Health Service(P >0.05).