A simplified D -creatine dilution method for skeletal muscle mass determination with dynamic correction of creatinine and D -creatinine using ultra-performance liquid chromatography-tandem mass spectrometry.

This study developed a simple method for muscle mass determination based on D -creatine dilution by removing the matrix effects of ultra-performance liquid chromatography-tandem mass spectrometry analysis through mutual correction of creatinine and D -creatinine. Rats were administered an oral tracer dose of D -creatine at age 6 weeks. Creatinine and D -creatinine in urine were detected using ultra-performance liquid chromatography-tandem mass spectrometry after diluting 20 times to obtain D -creatinine enrichment factor (mole percent excess).

Research progress in human biological monitoring of aromatic hydrocarbon with emphasis on the analytical technology of biomarkers.

Aromatic hydrocarbons are unsaturated compounds containing carbon and hydrogen that form single aromatic ring, or double, triple, or multiple fused rings. This review focuses on the research progress of aromatic hydrocarbons represented by polycyclic aromatic hydrocarbons (including halogenated polycyclic aromatic hydrocarbons), benzene and its derivatives including toluene, ethylbenzene, xylenes (o-, m- and p-), styrene, nitrobenzene, and aniline. Due to the toxicity, widespread coexistence, and persistence of aromatic hydrocarbons in the environment, accurate assessment of exposure to aromatic hydrocarbons is essential to protect human health.