Objective: To establish a method for the determination ofsamarium oxide and lanthanum oxide by inductively coupled plasmamass spectrometryin the air of workplace. Methods: Samarium, lanthanum and their compounds in the air of workplace were collected through microporous filter. The samples were digested by nitricacid and perhydrol (V/V=4∶1) and detected by inductively coupled plasmamass spectrometry. Results: The linear range ofsamarium oxide and lanthanum oxide was 0-50.00 μg/L, Sm₂O₃: y=0.0119x, r=0.9999; La₂O₃: y=0.0617x, r=0.9998. The detection limits were less than 0.1 μg/L, and the minimum detection concentration were less than 1.52×10^-5 mg/m³. The sampling efficiency were 100%, the recovery rates were 95.70%-102.01%, and the precision were 0.78%-1.58%. Conclusion The indicators established in this study are conformed with the requirements of Chinese Occupational Standars of GBZ/T 210.4-2008, "The Guidelines for the Development of Occupational Hygiene StandarsMehods Part 4: Determination of Chemical Substances in the Air of Workplace".

Objective To review the status of pesticide residues in vegetables and fruits and the progress of risk assessment, and to provide data support for pesticide residue research, residents' dietary exposure risks and safety risk management. Methods Domestic and international literature and research data available are reviewed and analyzed. Results This article mainly reviews the literature on the investigation of current status of pesticide residues in vegetables and fruits. It also discusses several methods and models that have been widely employed in the dietary exposure risk assessment of pesticide residues worldwide. Conclusion Pesticide residues have been frequently reported in vegetables and fruits, mainly including organophosphorus, organochlorine, carbamate and pyrethroid pesticide residues. The relevant risk assessment results indicate that different groups of people, especially those with high exposure, have cumulative dietary exposure risks to pesticides in vegetables and fruits. Although most pesticide residues have been detected at low concentrations in vegetables and fruits, they have potential toxicity risks and require continuous attention.

Because many therapeutic agents are contaminated by epimeric impurities or form epimers as a result of metabolism, analytical tools capable of determining epimers are increasingly in demand. This article is a proof-of-principle report of a novel DMS-MS/MS method to separate and simultaneously quantify epimers, taking PGF2 and its 8-epimer, 8--PGF2, as an example. Good accuracy and precision were achieved in the range of 10-500 ng/mL with a run time of only 1.5 min. Isopropanol as organic modifier facilitated a good combination of sensitivity and separation. The method is the first example of the quantitation of epimers without chromatographic separation.