Determination of lead content in medicinal plants by pre‐concentration flow injection analysis–flame atomic absorption spectrometry

Abstract

ABSTRACT:Introduction -Although medicinal plants are widely used throughout the world, few studies have been carried out concerning the levels of heavy metal contaminants present. Such metals are highly toxic to living organisms even in low concentrations owing to their cumulative eff ect. The present paper describes the the development of a pre-concentration fl ow injection analysis-fl ame atomic absorption spectrometric system to determine the lead content in medicinal plants at the ppb level. Objective -To develop a pre-concentration fl ow injection analysis-fl ame atomic absorption spectrometric system to determine the lead content in medicinal plants at the ppb level. Methodology -A pre-concentration fl ow system was coupled to a fl ame atomic absorption spectrometer. The plant samples were analysed after nitroperchloric digestion. The proposed system was optimised by evaluating the following parameters: nature, concentration and volume of the eluent solution, elution fl ow rate, elution effi ciency, pre-concentration fl ow rate and pre-concentration time. Results -The proposed system exhibited good performance with high precision and repeatability (RSD £ 2.36%), excellent linearity (r = 0.9999), low sample consumption (10.5 mL per determination) and an analytical throughput of 55 samples/h. Lead concentrations ranged from 3.37 ± 0.25 to 7.03 ± 0.51 mg/g in dry material. This concentration interval is greater than that previously published in the literature. Conclusion -The inclusion of a pre-concentration column in the fl ow manifold improved the sensitivity of the spectrometer. Thus, it was possible to determine the analyte at the ng/mL level in sample solutions of medicinal plants. This is a very important accomplishment, especially when the cumulative eff ect of heavy metals in living organisms is considered.

The content of lead in herbal drugs and tea samples

“…In the case of the remaining drugs, the overall content of lead ranged from between 1 and 2 μg/g ( Table 2). The degree of contamination of the soil surface from which the herbal drugs were collected had an effect on the overall content of heavy metal in the drugs, in addition to numerous pollutants (exhaust fumes from motor vehicles and industrial facilities, waste water) [14]. Chong Wei Jin et al [3] indicated that the overall lead content in green tea leaves depends on the area in which this plant type is being grown.…”

“…The total content of lead in normal human bodies ranges from 100 to 400 mg and increases with age. In blood, the normal level is below 400 ng/mL [14]. The deleterious properties of lead are particularly significant in the central nervous system, kidneys and liver.…”

The Assessment of Toxic Metals in Plants Used in Cosmetics and Cosmetology

“…Literature data indicates that cosmetic plants can be severely polluted with heavy metals. Information on this issue avoids or minimizes the use of plants contaminated with toxic metals in the production process [ 24 ].…”

In VitroAntimicrobial and Antiprotozoal Activities, Phytochemical Screening and Heavy Metals Toxicity of Different Parts ofBallota nigra

“…Since animals are sensitive to heavy metals concentration, as a result it produces different illnesses. Like animals, plants are also sensitive to heavy metals concentration [11]. Human activities play a major role in the increase of heavy metals concentration in environment.…”