Standard addition involves adding varying amounts of the analyte to sample portions of fixed mass or fixed volume and submitting those portions to the sample preparation procedure. After measuring the final extract solutions, the observed signals are linearly regressed on the spiked amounts. The original unknown amount is estimated by the opposite of the abscissa intercept of the fitted straigh...

The H-point standard addition method was applied to kinetic data for simultaneous determination of citric and ascorbic acid or selective determination of ascorbic acid in presence of citric acid. The method is based on the difference in the rate of reaction of citric and ascorbic acid with copper(II)-ammonia complex. The linear dynamic ranges for the two analytes of citric and ascorbic acid are...

A aplicação do método de adição padrão no ponto H para solucionar os espectros sobrepostos de hidroclorotiazida e propranolol foi avaliado. Os resultados mostram que o método HPSAM pode ser aplicado para a determinação simultânea dos compostos, em meio aquoso. Os resultados da aplicação do HPSAM mostraram que as duas drogas podem ser determinadas simultaneamente, numa razão de concentração hidr...

The H-point standard addition method (HPSAM), based on spectrophotometric measurements for simultaneous determination of beryllium and aluminium, is described. This method is based on the difference between their rates of reactions with Chrome Azurol S (CAS) in cetyltrimethylammonium bromide (CTAB) micellar media. The results showed that beryllium and aluminium could be determined simultaneousl...