Portable ion-selective electrode for determination of Cd, Pb, and Cu in cow and buffalo milk samples from industrial regions of Korba, Chhattisgarh, India.

Abstract

This study assessed the contamination of cadmium (Cd), lead (Pb), and copper (Cu) in milk samples from industrial areas of Korba, Chhattisgarh, India. Ion-selective electrodes (ISE) were used as a cost-effective and rapid alternative to atomic absorption spectroscopy (AAS) for metal detection. Microwave digestion with a 1:4 ratios of HClO₄ and HNO₃ ratio was optimized to decompose the milk matrix, enhancing the metal recovery rates from 92.1% to 96.0%. The developed method showed a good linearity (0.1-10 mg/L) with limits of detection for Cd, Pb, and Cu as 0.05, 0.03, and 0.04 mg/L, respectively. Statistical analyses (ANOVA, t-test, F-test) of metals in milk revealed no significant differences in results by ISE and AAS methods, confirming the reliability of electrode used in the present study. Target hazard quotient (THQ) values for Cd and Pb were found higher than those for Cu indicating the potential long-term health risks. Carcinogenic risk (CR) values for Cd were exceeded the tolerance limit at all the sites, and the CR values of Pb remained within the acceptable range. The study demonstrates that the use of ISE as an effective and portable tool for measurement of heavy metals in milk and supports the broader application in food safety monitoring.