Study on Optical Path Optimization for Direct Determination of Spectrophotometry of High Concentration Hexavalent Chromium Solution by Ultraviolet Visible Spectroscopy

Cr( Al) has severe toxicity and mobility in the environment, especially for high-concentration Cr( VI) in the industrial process. It is important to developing an accurate and practical method for its determination. This study described a new direct spectrophotometry for determining Cr (VI) solution based on optical path optimization. The method focused on the high-concentration and determination sensitivity of the Cr (VI) solution under different optical paths. The results showed that the linear determination concentration of Cr(VI)VI) solution increased to 1 500 mg center dot L-i by changing the optical paths (1, 5, 10, 30, 50, 100 mm), and the determination sensitivity increased by 100. 3 times (from 0. 001 6 to 0. 161 5 L center dot mg) linearly from 1 to 100 mm. Based on the highest sensitivity, the optical path optimization method was studied on the premise of ensuring accuracy. Different concentrations have the highest sensitivity under different optical path measurement conditions. In addition, the results showed that under the condition of coexistence of Cr (VI) with trivalent Cr (DI) Fe (DI) Cu (II) and Ni (II) in a certain proportion, the method had good anti-ion interference performance, and the accuracy of the determination results was hardly affected by the change of temperature (5 similar to 30 degrees C). The method was also successfully applied to analyse high-concentration Cr (1/I) in practical electroplating wastewater samples. Moreover, compared with other common Cr ( VI) determination methods, this method showed a wider Cr( YI) concentration linear range (0. 003 96 similar to 1 500 mg center dot L i), higher analytical accuracy of high-concentration Cr(Al)Al) solutions, and rapid determination time (1. 5 min). Therefore, this method had good application prospects in the industrial process for environmental analysis and monitoring of the Cr( VI) solution.