QUANTITATIVE ASSESSMENT OF HEAVY METAL CONTENT IN “HIBISCUS MICRANTHUS LINN”

The heavy metal analysis of Hibiscus Micranthus was conducted using the Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) instrument, employing a precise and robust methodology. Approximately 20 mg of the plant sample was subjected to microwave-assisted digestion using ultrapure nitric acid, ensuring complete breakdown of the matrix over a 45-minute digestion period. The digested sample was then diluted to a final volume of 50 mL for analysis. To guarantee accurate quantification, calibration standards of arsenic, cadmium, mercury, and lead were prepared at concentrations ranging from 2 µg/mL to 10 µg/mL, which established high linearity for each respective metal, with correlation coefficients exceeding 0.996. The ICP-OES instrument was optimized with an RF power setting of 1.2 kW, a plasma gas flow rate of 12 L/min, and a nebulizer gas flow rate of 0.70 L/min to enhance the sensitivity and reproducibility of detection. Analytical results indicated that the levels of all tested heavy metals arsenic, cadmium, mercury, and lead—were below the detection limits of the instrument, signifying negligible or non-detectable contamination in the Hibiscus Micranthus sample. This outcome confirms the sample's safety for pharmaceutical or herbal applications, minimizing concerns related to heavy metal toxicity. The study further validated the analytical procedure by documenting calibration curves and linearity graphs, reinforcing the reliability of the method used. Overall, this ICPOES-based evaluation establishes a trustworthy framework for heavy metal determination in herbal materials, contributing critical insights into the quality control of Hibiscus Micranthus and endorsing its continued use where safety is paramount. The results are significant for researchers and manufacturers focused on ensuring contaminant-free botanical products through advanced instrumental techniques.