This study presents a new technique for determining vitamin B12 in milk powder using high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). We used ultrasonics with potassium ferrocyanide and zinc acetate solutions to extract the samples. ⁵⁹Co was employed as the analytical target for cyanocobalamin. It was separated using a Phenomenex Luna 5 μm C18 (250 × 4.6 mm) chromatographic column with a mobile phase consisting of 1.6 mmol/L EDTA and 0.4 mmol/L KH₂PO₄ in a 60% v/v methanol solution (pH = 4.0). The sample has an excellent separating degree for free cobalt and cyanocobalamin, and isocratic elution can be finished within 4.0 min. To eliminate the matrix interference due to the presence of milk powder, we applied collision mode (KED). The linear range of cyanocobalamine ranged from 1.0 μg/L to 20 μg/L, with correlation coefficients (r²) of 0.9994. The limit of detection (LOD) was 0.63 μg/kg, and the limit of quantitation (LOQ) was 2.11 μg/kg. The mean recoveries were in the range of 87.4–103.6%. The accuracy and precision of the developed method are well suited for the fast quantification of the trace vitamin B12 in milk powder.

Although lipophilic shellfish toxins (LSTs) pose a significant threat to the health of seafood consumers, their systematic investigation and risk assessment remain scarce. The goals of this study were as follows: (1) analyze LST levels in commercially available shellfish in Zhejiang province, China, and determine factors influencing LST distribution; (2) assess the acute dietary risk of exposure to LSTs for local consumers during the red tide period; (3) explore potential health risks of LSTs in humans; and (4) study the acute risks of simultaneous dietary exposure to LSTs and paralytic shellfish toxins (PSTs). A total of 546 shellfish samples were collected. LSTs were detected in 89 samples (16.3%) at concentrations below the regulatory limits. Mussels were the main shellfish species contaminated with LSTs. Spatial variations were observed in the yessotoxin group. Acute exposure to LSTs based on multiple scenarios was low. The minimum tolerable exposure durations for LSTs calculated using the mean and the 95th percentile of consumption data were 19.7 and 4.9 years, respectively. Our findings showed that Zhejiang province residents are at a low risk of combined exposure to LSTs and PSTs; however, the risk may be higher for children under 6 years of age in the extreme scenario.

The simultaneous determination of arsenic and mercury species in human urine is critical for clinical diagnostics and therapeutic monitoring because it reduces the costs, time, and consumption of samples. This study proposes a method of utilizing high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for the concurrent analysis of arsenic and mercury species in urine samples. The separation was performed using a Hepu AR 5 μm C₁₈ (250 × 4.6 mm) column, employing a mobile phase composed of 0.1% L-cysteine, 5 mM NH₄H₂PO₄, and 4 mM tetrabutylammonium hydroxide (TBAH). The samples were diluted with water, and matrix interference was reduced through the application of a kinetic energy discrimination (KED) mode. Calibration curves for four arsenic species and three mercury species exhibited strong linearity within the range of 1–20 μg L⁻¹, with correlation coefficients (r) above 0.999. The limits of detection (LOD) ranged from 0.030 to 0.086 μg L⁻¹, while the limits of quantitation (LOQ) were observed to range from 0.10 to 0.29 μg L⁻¹. The spiking recoveries for all species varied from 87.0% to 110.3%, and the intra-day and inter-day relative standard deviations (RSD) were determined to be 1.1–6.0%, and 0.8–9.2%, respectively. These results indicate that the developed method achieves high precision, accuracy, and suitability for clinical applications, offering valuable insights for the diagnosis and treatment of heavy metal exposure.

Nickel (Ni) is a silver-white metal with high antioxidative properties, often existing in a bivalent form in the environment. Despite being the fifth most abundant metal on Earth, anthropogenic activities, including industrial processes, have elevated Ni levels in environmental media. This study investigated Ni contamination in various food groups in Zhejiang Province, China, mainly focusing on Ni levels in beans, vegetables, aquatic foods, meat products, cereal products, and fruits. A total of 2628 samples were collected and analyzed. Beans exhibited the highest Ni content in all samples. The overall detection rate of Ni was 86.5%, with variation among food categories. For plant-origin foods, legumes had the highest Ni concentration while for animal-origin foods, shellfish showed the highest median Ni concentration. The results indicate generally acceptable Ni exposure levels among Zhejiang residents, except for children aged 0–6. Beans were identified as the primary contributor to high Ni exposure risk. The paper suggests monitoring Ni contamination in food, especially for vulnerable populations, and provides insights into exposure risks in different age groups.

This study assessed elemental exposure and health risks in 35 prepared livestock and poultry dishes from Zhejiang Province using inductively coupled plasma mass spectrometry (ICP-MS). Aluminum (Al) showed the highest concentrations, while strontium (Sr) and barium (Ba) were moderate; other elements (molybdenum (Mo), chromium (Cr), lead (Pb), cadmium (Cd), thallium (Tl), cobalt (Co), arsenic (As)) were low; and nickel (Ni) was undetected. All dishes complied with GB 2762-2022 limits. Although seven dishes showed mild-to-moderate single-factor contamination, Nemerow indices confirmed safe levels (P_c < 0.7). Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) indicated that processing methods drove contamination profiles, with deep-fried products accumulating higher metal levels than stir-fried or boiled ones. While non-carcinogenic risks were acceptable for adults, children showed higher susceptibility with Total Target Hazard Quotients (TTHQ) values nearly double those of adults, exceeding safety thresholds in certain dishes primarily due to As and Cr. Carcinogenic risks for hexavalent chromium (Cr(VI)) and inorganic arsenic (iAs) were acceptable (1 × 10⁻⁶ to 1 × 10⁻⁴) for 32 dishes. After speciation-based recalibration, the remaining three dishes also fell within safe limits. Overall, exposure risks are low, though specific deep-fried products warrant monitoring.