HRMS analysis of pesticides in vegetables from Shanghai and risk assessment.

A rapid analytical method for the simultaneous determination of 550 pesticide residues in vegetable samples was developed based on ultra-high performance liquid chromatography-tandem Q/Orbitrap high-resolution mass spectrometry (UPLC-Q/Orbitrap-HRMS). To investigate the risk of exposure to pesticide residues through vegetable consumption, 704 leafy vegetable samples from Shanghai were analysed for multiple residues using this method. A total of 54 pesticide residues were identified in these vegetable samples and 302 samples contained one or more pesticide residue. The levels of the detected pesticides did not pose a health risk in the long term and were acceptable according to the results of the chronic dietary risk assessment. Risk rankings displayed that most of the pesticides were low to medium risk. The findings of this study provide a reference for future pesticide monitoring programmes.

Pesticides and risk assessment in Shanghai fruit and raw eaten vegetables.

A database of 392 pesticides established by an Ultrahigh performance liquid chromatography-tandem Q/Orbitrap high-resolution mass spectrometer (UPLC-Q/Orbitrap-HRMS) was used to screen multiple residues of pesticides in fruit and raw eaten vegetables from planting farms in Shanghai. Risk assessment was conducted with the screened results of the determined pesticides as to evaluate food safety. In 95% of the samples, one or more pesticides had a content below the maximum residue limits (MRLs) as set in the national Chinese standard. The co-occurrence of multi-residues of pesticides was more severe in peach and muskmelon, when compared with other food. All hazard index values of different groups were in the range of 0.19% to 12.3%, demonstrating that chronic dietary risk of studied fruits and raw eaten vegetables is low and the studied food samples were safe for human consumption in terms of these detected pesticides.

[Situation and assessment of heavy metal pollution in river and mud in one city in Henan Province].

OBJECTIVE: To study the heavy metal contamination status in river water and mud in the suburb of a city in Henan Province. METHODS: Typical sampling method is used to select a farmland irrigation river of the suburb of a city. Use the atomic absorption spectrophotometry, and measure the heavy metal cadmium (Cd), copper (Cu), lead (Pb) in the river water samples and mud samples by graphite furnace method and flame method, respectively. The results of water were compared with GB 3838-2002, Environmental Quality Standards for Surface Water, and GB 5084-2005, Standards for Irrigation Water Quality. The results of mud were compared with national soil background value. The contents of Cu and Cd in the river samples do not exceed the standard, and that of Pb is 3 to 6 times higher than the standard. According to the single factor pollution index method, the single factor pollution indice of Cu, and Cd in the river are less than 0.2 and are of clean level, while that of Pb reaches 6.84, indicating the Pb pollution in river water is severe. Cu in mud is more than 4 times of the soil background value, and that of Cd is more than 69 times of the soil background value, and that of Pb is more than 2 times of the soil background value. The single item pollution index indicates, in mud, the pollution index of Pb is 2.5, medium level pollution. The pollution indice of Cu and Cd in mud are more than 3, is severe pollution, and the Cd pollution is especially heavy, and the single pollution index reaches 67.76. The comprehensive pollution indice of the river and the mud are 5.346 and 84.115, respectively, indicating that both are at heavy pollution level. The main pollution source of the river originates from Pb, and that of the mud is from Cd and it is required to take measure and control as early as possible.