Preparation of Water Hardness Colorimetric Card with Calcium Ion as Index

DOI: https://doi.org/10.62517/jlsa.202407210

Author(s)

Qiyue Zhu, Shiyi Liu, Zitong Fang, Yi Wu, Chuyi Xie, Yinyi Xiao, Yongchun Wei*

Affiliation(s)

School of Materials and Environment, Zhuhai College, Beijing Institute of Technology, Zhuhai, Guangdong, China *Corresponding Author.

Abstract

The aim of this study was to explore the accuracy of chrome-black T as an indicator for determination of calcium ion concentration in water. By comparing the color changes of the solution under different reaction conditions, the optimal reaction conditions were determined as follows: under the condition of pH=9, the volume of chrome black T was 0.1mL and the reaction time was 10s. The final reaction color is made into a colorimetric card for the determination of water hardness, the results show that at a pH value of 9, chromium black T forms a colored complex with calcium ions, which has good stability, sensitivity, and identification. This colorimetric method has demonstrated high precision, reproducibility, and accuracy in actual water sample testing, and is expected to be widely applied in fields such as domestic water detection and other fields.

Keywords

Chrome Black T; Calcium Ion; Color Reaction; Colorimetric Card

References

[1] Luo Jiguo. Discussion on Methods for Determining Water Hardness in Water Quality Testing. Modern Salt Chemical Industry, 2023, 50 (05): 61-62+100. [2] Li Feng, Zhou Zhiqin. Simultaneous Determination of Calcium and Magnesium in Environmental Water Samples by Dual-Wavelength Spectrophotometry. Spectroscopy Laboratory, 2001, 18(2): 278—230. [3] Liu Wenming, Ma Weixing, Qian Baohua. Determination of Water Hardness by Chromazurol T Photometry. Physical Testing and Chemical Analysis Part B: Chemistry, 2000, 36(9): 426—427. [4] Chen Hualin, Feng Zhongqiong, Zhang Zhijian, et al. Factors Affecting the Determination of Calcium Ion Concentration by EDTA Titration and Optimization. Journal of Southwest University for Nationalities (Natural Science Edition), 2020, 46(06): 578-585. [5] Wu Dan, Hu Yinglu. Experimental Methods for Determining Total Hardness of Water by EDTA Titration. Laboratory Research and Exploration, 2021, 40(06): 59-63+123. [6] Ye Tingxiu, Luo Hongyuan, et al. Fluorescence Semi-quantitative Detection of Peroxide Value in Oilseeds of Chinese Herbal Medicine. Journal of Analytical Science, 2023, 42(09): 1188-1193. [7] Deng Fangkun, Cai Dezhen, et al. Preliminary Report on Field Test Results of Citrus Huanglongbing with Rapid Test Kit for Yellow Dragon Disease Using Color Card. Biochemical Engineering, 2023, 9(02): 102-108+113. [8] Geng Xuhao, Dong Jing, He Hui. What is Water Hardness. Chinese Journal of Frontier Health and Quarantine, 2023, 46(02):174.