Determination of ultra trace amount Chromium in water samples with the 1-(2-PyridylAzo)-2-Naphthol, (PAN) by the bromate ion in sulfuric acid with kinetic spectrophotometric method

Subject Areas : Journal of Physical & Theoretical Chemistry

Mohamad Reza  Froudi Jahromi ¹ (Chemistry Department, Dashtestan Branch, Islamic Azad University, Dashtestan, Iran)
Samira  Zandifar ² (Chemistry Department, Dashtestan Branch, Islamic Azad University, Dashtestan, Iran)
Ehsan  Pakdaman ³ (Chemistry Department, Islamic Azad University, Kangan branch, Kangan, Iran)
Fatemeh  Tavakoli ⁴ (Chemistry Department, Islamic Azad University, Kangan branch, Kangan, Iran)
Saideh  Bagheri ⁵ (Young Researchers and Elite Club, Shiraz Branch, Islamic Azad University, Shiraz, Iran)

Received: 2016-01-06 Accepted : 2016-01-06 Published : 2016-03-01

Keywords: Chromium (III), Kinetic, 1-(2-PyridylAzo)-2-Naphthol, (, Determination, Spectrophotometic,

Abstract :

A new kinetic spectrophotometic method for the determination of trace amount Chromium (III) in Teareal samples has been described based on it s the catalytic effect on the oxidations of 1 - ( 2 PyridylAzo ) - 2 - Naphthol, (PAN), by potassium bromated in sulfuric acid. The reaction is followedspec- trophotometrically by measuring the decrease in the absorbance at 469 nm. Under the optimumconditions of0.2 molL-1 sulfuric acid, 1.0 × 10-4 molL-1, 1- ( 2 -PyridylAzo ) - 2 - Naphthol, (PAN),0.01 molL-1 potassium bromate at 35oC, calibration graph in the rang of 0.001-0.06 ngL-1 Chromium(III). Concentration was obtained with detection limit of 0.2303 g mL-1 by the fixed-time method of5.5 min. The relative standard deviation for 0.05AngL-1 Chromium (III) is %90. No serious interferencewas identified. The applicability of the method was demonstrated by the determination of theChromium (III) in Water, Vegetables and blood samples.