Determination of polyfluoroalkyl substances in cosmetic products using dispersed liquid-liquid extraction coupled with UHPLC-MS/MS.

Human exposure to polyfluoroalkyl substances (PFASs) via cosmetics has been of increasing concern due to the tremendous detrimental health impacts of PFASs. Developing an effective method for extracting and determining PFASs in cosmetics is crucial in accurately assessing their corresponding human exposure risk. Herein, this study developed a new sample pre-treatment method to address the challenges posed by the variety and complexity of cosmetic matrices. Seventeen PFASs in cosmetic products, including 9 perfluoro carboxylic acids and 8 perfluorosulfonic acids, were simultaneously determined using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The whole pre-treatment process can be divided into three steps. In step 1, cosmetics with diverse matrix types can be effectively dispersed during extraction by using saturated sodium chloride-acetonitrile and saturated sodium chloride-tetrahydrofuran as extraction solvents. In step 2, the pre-purification step employs a potassium ferrocyanide-zinc acetate co-precipitant to remove high molecular weight interferents from the extraction solution, thereby enhancing the efficiency of solid-phase extraction (SPE). In step 3, WAX-SPE is utilized to further eliminate interferents from the extraction solution while concentrating the analytes, meeting the trace analysis requirements for PFASs in cosmetics. The method detection limits were 0.09-0.26 ng g-1. The recoveries ranged from 70.1% to 114.7%, with relative standard deviations in the range of 2.0-19.1%. The method was applied to cosmetic samples in the Guangzhou market, and the total concentration of PFASs ranged from 0 to 10.8 ng g-1. This method has strong anti-interference ability, good applicability, high sensitivity, and good reproducibility, making it suitable for the analysis and detection of perfluorinated acids in cosmetic samples. It provides technical support for cosmetics safety regulation.

[Soil-crop Distribution and Health Risk Assessment of Organochlorine Pesticides on Typical Agricultural Land in Southern Leizhou Peninsula].

The residual content of organochlorine pesticides (OCPs) in soil and crops of typical agricultural land in the southern Leizhou peninsula were determined using gas chromatography-mass spectrometry (GC-MS). Additionally, the bioconcentration factors of organochlorine pesticides in eight crops were investigated, and the human health risk was evaluated. The results indicated that 10 types of OCPs were detected to varying degrees; HCHs and heptachlor were the main OCPs in the study area, with the residual contents of 23.83-111.51 ng·g-1 and 11.01-25.97 ng·g-1 in soil and 7.54-61.28 ng·g-1 and 3.96-30.97 ng·g-1 in crops, respectively. A small number of soil and crop samples were found to exceed the standard. The ratio of α-HCH/γ-HCH was less than 1 in 87.50% of the soil samples, and ß-HCH/α-HCH was larger than 1. This indicates that the HCHs were probably derived from the recent use of lindane and historical residual pollution, whereas the heptachlor was mainly derived from underground insect pests and the application of termite control agents. The enrichment ability of OCPs was significantly different among different crops. The bioaccumulation capacity of vegetables was higher than that of fruit. Furthermore, bulb vegetables (leeks) were significantly stronger than other vegetables. A human health risk assessment of OCPs showed that OCP-combined pollution would not cause significant health risks to the population in the study area. However, the maximum value of HI in some crop samples was greater than 1, indicating that there were still potential risks, which should not be ignored.