Determination of total urinary 2,5-hexanedione in the Chinese general population

Objective: Determination of the urinary levels of 2.5-hexanedione (2,5-HD) was performed in subjects belonging to the Chinese general population to define the reference value for this metabolite. Methods: Urine samples were collected from 8235 individuals (4216 men and 4019 women) from the healthy general population who had not been occupationally exposed to n-hexane or methyl-n-butyl ketone. The determination was performed by a gas chromatography mass spectrometry method using an ion-trap mass spectrometer. Results: The result showed that the urinary 2,5-HD median level was 0.159 mg/L for the total samples. Males had statistically significant higher excretion of 2,5-HD in urine than females (median 0.171 mg/L compared to 0.147 mg/L, Z = -8.21, P < 0.001). There was a statistically significant difference in urinary 2,5-HD levels among age groups. The excretion of 2,5-HD in urine was related to increasing age (r = 0.160, P < 0.05). There was statistically significant difference in urinary 2,5-HD levels among people from difference provinces. The results showed that there was also a statistically significant effect in urinary 2,5-HD levels between current smokers and non-smokers. Conclusion: Finding a measurable amount of 2,5-HD in urine does not mean that the level of 2,5-HD causes an adverse health effect. Biomonitoring studies on levels of urinary 2,5-HD can provide physicians and public health officials with reference values so that they can determine whether people have been exposed to higher levels of 2,5-HD than are found in the Chinese general population. These data can also provide a foundation for scientists to make a plan for further study. (C) 2016 Elsevier Inc. All rights reserved.