Selective Kinetic-Spectrophotometric Determination of Trace Amounts of As(III) Based on an Induction Period
Year: 2012
Type: article
Abstract: A new, selective, sensitive, and simple kinetic spectrophotometric method is proposed for thedetermination of As(III) in the presence of As(V) in alloys and water samples. This method is basedupon the inhibiting effect of As(III) on the redox reaction between sodium periodate and meta-cresolpurple (MCP) in acidic media. The reaction induction period is proportional to the concentration ofAs(III). The decolorization of MCP is used to monitor the reaction spectrophotometrically at 525 nm.As(III) can be determined in the range of 0.08–3.0 μg mL-1 under optimum conditions. The detectionlimit of the method with 3σ criteria is 0.08 µg mL-1. The relative standard deviations for eight replicatedeterminations of 0.20, 0.60, and 0.80 μg mL-1 As(III) are 5.0%, 4.8%, and 1.9%, respectively. Therecovery percentage ranges from 96.0% to 103.3%. The influence of various foreign species is alsostudied; As(V) does not interfere with the As(III) measurement even when present in1000-fold greaterthan As(III). This method can successfully be used to determine As(III) concentration in syntheticalloys and spiked water samples.
Language: English
Subfield: Analytical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W1605456375