NGHIÊN CỨU XÁC ĐỊNH HÀM LƯỢNG MỘT SỐ KIM LOẠI NẶNG TRONG HƯƠNG NHU TÍA VÙNG BẮC TRUNG BỘ BẰNG PHƯƠNG PHÁP QUANG PHỔ HẤP THỤ NGUYÊN TỬ (AAS)

Tóm tắt

The content of some heavy metals such as cadmium, copper, iron, manganese, nickel, lead, and zinc
(Cd, Cu, Fe, Mn, Ni, Pb, Zn) in Ocimum Tenuiflorum grown in the two provinces of Nghe An and Ha Tinh in
the North Central region of Vietnam was determined using atomic absorption spectrometry with flame
atomization (F-AAS) after sample digestion in microwave oven. The analytical results were compared with
the agricultural crop guidelines of FAO/WHO, showing that the heavy metal content was within the limits.
The analytical results were also compared with some other studies on Ocimum Tenuiflorum and found
finding that the content of Cu, Fe, Mn, Zn was higher, while the content of Cd, Ni, Pb was lower than those
in the later issues. According to WHO standards on medicinal herbal ingredients, the content of Cd, Cu, Mn,
Pb was below the permissible limits in all samples; the content of Fe in HN1, HN3, HN5 samples exceeded
the recommended value; the content of Zn in the HN4 sample exceeded the permissible limits. The
concentration range of heavy metals varied, with the levels of toxic metals such as Cd, Pb, and Ni all below
the detection limit for all samples. For other heavy metals, the content of Fe and Mn in sample HN1
(191.606; 96.429 mg/kg) and the content of Cu and Zn in sample HN4 (16.597; 133.561 mg/kg) were is the
highest. The analysis method used had a low detection limit, achieving thresholds lower than 59 ppb for Cd,
Fe, Mn, Ni, Pb, Zn and 0.1 ppm for Cu. The relative standard deviation (% RSD) of 10 repeat measurements
of low-concentration heavy metal content was all less than 3.530%; and the recovery of elements were in the
range from 87.652 to 109.812%, which met AOAC requirements for trace.