Determination of the Sulfate Ion Concentration in Rain Water by Flow Injection Analysis Incorporated with a Barium Chloranilate Reaction Column

Abstract

The concentration of sulfate ions in rain water was determined by a flow-injection method using a reaction column packed with barium chloranilate powder. Aqueous ammonium chloride (0.5%) containing 50% ethanol was used as a carrier at a flow rate of 1.9 ml/ min. The chloranilate ion concentration, which corresponds to the sulfate ion concentration, in the carrier from the reaction column was monitored by a photometric detector at 530 nm. Interferences by multivalent cations were eliminated with the use of a cation-exchange column inserted in the upper stream of the reaction column. The concentrations of sulfate ions in rain water (4 -100 ppm) were quickly determined (one sample per minute) with high reproducibility. The results agreed well with those obtained by the standard manual method.

Flow-Injection Spectrophotometric Determination of Micro Amounts of Sulfate Ion in Surface- and Sea-Water Samples with a Barium Chromate Reaction Column

“…The proposed method gave a linear calibration curve in the concentration range of 0.5 to 5 ppm sulfate ion; thus, the sensitivity is approximately 10-fold as good as that of the methods reported by Yakata et al 9, to The relative standard deviation of ten measurements was 0.75% for a 3 ppm sulfate ion standard solution.…”

Emprego de reagente em suspensão em sistema de injeção em fluxo: determinação espectrofotométrica de sulfato em águas naturais

“…Na primeira etapa dos estudos, foram feitos experimentos que utilizaram cloranilato de bário empacotado em minicoluna inserida em linha 3 . A seguir serão descritos os experimentos que foram reali- A solução de EDTA foi introduzida em fluxo intermitente no ponto z da Figura 2.…”

“…Nestes experimentos empregaram-se soluções padrão de sulfato 0,0 e 20,0 mg L -1 preparadas em ausência e presença de Al 3+ (50 mg L -1 ), Ca 2+ (40 mg L -1 ), Fe 3+ (2,0 mg L -1 ), HPO 4 2-(1,0 mg L -1 P), F -(1,0 mg L -1 ) e Cl -(195 mg L -1 ), CO 3 2-(60,0 mg L -1 ), Na + (50,0 mg L -1 ), Mg 2+ (15,0 mg L -1 ). Tais soluções sofreram diluição em torno de 37% na confluên-cia com etanol antes de serem introduzidas na alça de amostragem, pois foram bombeadas com vazões de 2,0 e 1,2 mL min -1 respectivamente.…”

“…Alguns autores apresentaram esta possibilidade descrevendo sistemas onde a parte sólida pode ser acomodada em coluna [2][3][4] , utilizando-se ou não a imobilização em partículas esféricas de celulose 5,6 . O uso de câmara de agitação também foi proposto para esta finalidade 7 , onde um contato vigoroso entre reagente pouco solúvel e amostra líquida é necessário, pois esta interação química dá origem a uma terceira espécie mensurável espectrofotometricamente.…”

Sulfate-Selective Electrode of Poly(vinyl chloride) Membrane Impregnated with Barium Chloranilate

“…One method is to decompose organic sulfur compounds in a combustion flask followed by sulfur determination by gravimetryl or ion chromatography.2,3 A photometric method for the determination of sulfate ions in natural water or rain was also proposed which uses barium chromate or barium chloranilate. 4,5 Recently, chloranilic acid has been used in precipitation titrations with biamperometric end-point detection for the indirect determination of sulfate and phosphate ions.6' Ion-selective electrodes are useful for ionactivity measurements in many fields; anion-selective membrane electrodes have been described by Pungor.8 Highly selective electrodes for iodide, chloride and bromide were developed using a precipitate-impregnated membrane electrode.9-11 Attempts have also been made to construct electrodes that are selective to sulfate or phosphate ions.12 The usefulness of the sulfate-and phosphate-sensitive membranes proposed by Pungor was examined by Rechnitz.13 Strivastava and Jamn have discussed a solid-state heterogeneous sulfate membrane of polystyrene in which hydrous thorium oxide powder was dispersed.14 The construction and application of a chloranilate liquid-membrane electrode were reported by Veltsistas and Karayannins. 15 We have also studied the determination of sulfate ions in seawater or of sulfur as sulfate ions in organic compounds using a sulfateselective electrode.…”