Paper, board and pulp. Determination of water-soluble sulfates

Abstract A turbidimetric procedure is described forthe determination of soluble sulfates in water-soluble color additives. The color additive is adsorbed on activated carbon, the sulfates in the filtrate are precipitated as barium sulfate, and the turbidity is measured spectrophotometrically at 440 nm . The precision of this method is m0.1% in the range of 0.1–2.5% sodium sulfate.

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Simultaneous Spectrophotometric Determination of Salbutamol by Coupling with Diazotized 4-Aminobenzoic acid

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.v8i1.8435 ◽

2017 ◽

Vol 8 (1) ◽

Author(s):

Hind Hadi ◽

Gufran Salim

Keyword(s):

Pharmaceutical Preparations ◽

Coupling Reaction ◽

Dosage Forms ◽

Water Soluble ◽

Trace Determination ◽

Aminobenzoic Acid ◽

Optimum Conditions ◽

Colored Product ◽

Versus Concentration

A simple, rapid and sensitive spectrophotmetric method for trace determination of salbutamol (SAL) in aqueous solution and in pharmaceutical preparations is described. The method is based on the diazotization coupling reaction of the intended compound with 4-amino benzoic acid (ABA) in alkaline medium to form an intense orange, water soluble dye that is stable and shows maximum absorption at 410 nm. A graph of absorbance versus concentration indicates that Beer’s law is obeyed over the concentration range of 0.5-30 ppm, with a molar absorbtivity 3.76×104 L.mol-1 .cm-1 depending on the concentration of SAL. The optimum conditions and stability of the colored product have been investigated and the method was applied successfully to the determination of SAL in dosage forms.

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