Application of ICP-MS in Quantifying the Accumulation of Trace Heavy Metals in Thai Basil (Ocimum basilicum)

This study investigates the accumulation of heavy metals (HMs) in basil (Ocimum basilicum) cultivated in three communes—Hong Thai, Tan Dan, and Quang Lang—of Phu Xuyen District, Hanoi, Vietnam. A total of 45 samples, including 15 basil, 15 soil, and 15 irrigation water samples, were collected between February and June at approximately 25-day intervals. The concentrations of six heavy metals (Fe, Cu, Zn, As, Cd, Pb) were analyzed using standard analytical methods. In basil samples, essential micronutrients such as Fe, Cu, and Zn showed increasing concentrations over time, with maximum values of 48.53 mg/kg (Fe), 6.10 mg/kg (Cu), and 23.60 mg/kg (Zn). These values remained within the permissible limits of QCVN 8-2:2011/BYT. Toxic elements such as Cd were below detection limits in all samples, while Pb levels in Quang Lang basil samples reached up to 0.246 mg/kg—approaching the national limit of 0.3 mg/kg. Arsenic concentrations in Tan Dan soil (up to 13.8 mg/kg) and water (up to 0.046 mg/L) were close to the limits specified by QCVN 03-MT:2015 and QCVN 08-MT:2015, respectively. Bioconcentration factor (BCF) analysis revealed that basil accumulated Zn and Cu more significantly than other metals, especially during the rapid growth stages from March to May. The findings underscore the importance of monitoring heavy metal content in vegetable production areas, particularly those near residential and craft village zones, to ensure long-term food safety and environmental sustainability.