Flotation-Assisted Homogenous Liquid–Liquid Microextraction for Determination of Cadmium in Vegetables

Health Risk Assessment of Lead, Cadmium, and Arsenic in Leafy Vegetables in Tehran, Iran: the Concentration Data Study

Absorption of heavy and toxic metals causes their accumulation in the edible parts of vegetables. Pollutants such as heavy metals have directly affected the health of society and contributed to emerging diseases in recent years. The current study aimed to detect heavy metals (Pb, Cd, As) in highly consumed leafy vegetables provided from the Tehran market. Four types of vegetables, including dill, parsley, cress, and coriander were selected and 64 samples were randomly collected from fruit and vegetable markets in different regions of Tehran in August and September 2022. Then, samples were analyzed by the ICP-OES system, and health risk assessment was conducted using non-carcinogenic and carcinogenic approach. The range of Pb concentration was 54-314, < LOQ-289, < LOQ-230, and < LOQ-183 μg/kg for dill, cress, parsley, and coriander, respectively. The high mean concentrations of Pb belong to the dill (161.43 ± 77.3 μg/kg) and cress (154.75 ± 72.9 μg/kg). In some samples of dill (37.5% of samples), cress (18.75% of samples), and parsley (12.5% of samples), the Pb content was above the national allowable limit (200 μg/kg). The range of Cd concentration was < LOQ-42, < LOQ-41, < LOQ-30, and < LOQ-38 μg/kg for dill, cress, parsley, and coriander, respectively. In none of the samples, the concentration of Cd was higher than the Iranian national limit (50 μg/kg). The As occurrence was observed in all cress samples with a mean of 165.19 ± 64.83 μg/kg. The range of As concentration was < LOQ-71, < LOQ-256, 58-273, and < LOQ-75 μg/kg for parsley, dill, cress, and coriander, respectively. The THQ and HI values were higher than 1, and either ILCR value was higher than 10-4 for all tested heavy metals, it can be concluded that higher levels of heavy metals than the standard limits in some samples may raise the warning alarm and should come to the attention of the authorities.

Monitoring of Cobalt and Cadmium in Daily Cosmetics Using Powder and Paper Optical Chemosensors

Daily used cosmetics may contain high levels of heavy metals which are added to improve the quality and shine of cosmetics but represent a threat to human health. In this report, powder- and paper-based optical nanosensors using mesoporous silica nanospheres as carriers were designed for determination of Co²⁺ and Cd²⁺ in commonly used cosmetics. Powder optical chemosensors (POCs) were prepared via direct decoration of optical probes into a porous carrier. Paper-based chemosensors (PBCs) were designed via adsorbing the organic chromophore onto filter papers treated with mesoporous silica. POCs and PBCs were constructed with thick decoration of optical probes, leading to the formation of active surface centers for monitoring of Co²⁺ and Cd²⁺ in cosmetic products. The uniform structures of POCs and PBCs have resulted in selective sensing and low detection limits up to parts per billion, wide detection range determination, and fast response (on the order of seconds). Digital image colorimetric analysis (DICA) was used to quantify the color of PBCs and deduce the corresponding concentrations of Co²⁺ and Cd²⁺ using calibration curves. DICA data correlated well with that obtained from UV-vis spectrophotometry. The developed POCs and PBCs showed wide detection ranges of metal ions and a considerably low detection limit under optimal analysis conditions. The low limit of detection of Co²⁺ and Cd²⁺ ions using POCs was 6.7 × 10^-9 and 3.5 × 10^-9 M, respectively. To the best of our knowledge, this is the first time simple PBCs have been designed for monitoring Co²⁺ and Cd²⁺ with detection limits of 2.2 × 10^-7 and 1.3 × 10^-7 M. A limited amount of manufactured POCs (about 20 mg) were used for all measurements, and commercial filter paper treated with mesoporous nanosphere silica was used for sensing Co²⁺ and Cd²⁺ ions. The developed optical chemosensors had short regeneration times and exhibited high stability and surface functionality and are capable of monitoring Co²⁺ and Cd²⁺ in various cosmetic products.