Volatile, Toxic And Small Molecular Aldehydes And Their Derivatives In Chinese Liquor

Chinese liquor, with rising production, is the traditionally indigenous distilled spirit in China. In recent years, consumers growing concerns about safety problem of liquor, which is the reason for study on harmful compounds in liquor. To our knowledge, few researches on volatile, toxic and small molecular aldehydes in Chinese liquor have been published. Among them, formaldehyde and acetaldehyde were classified as group 1(sufficient evidence of carcinogenicity) by International Agency for Research on Cancer(IARC). Acrolein was classified as group 3 by IARC. However, in Chinese liquor field, formaldehyde, acetaldehyde and acrolein standards have not been set. In this paper, formaldehyde, acetaldehyde and acrolein were detected in distillation cut, raw liquor and finished liquor. Furthermore, the margin of exposure(MOE) approach was applied to assess the risk of formaldehyde, acetaldehyde and acrolein in Chinese liquor.The details are as follows:(1) Formaldehyde, acetaldehyde and acrolein and their precursors as well as main derivatives were identified and quantified in Chinese liquor by derivatization, head space-solid phase microextraction(HS-SPME), gas chromatography–mass spectrometry(GC-MS), liquidliquid microextraction(LLME) and GC–flame ionization detector(GC-FID). The methods showed good linearity over a wide concentration range. The correlation coefficient(R2) were 0.991(1,1-diethoxymethane) to 0.998(1,1,3-triethoxypropane). The relative standard deviations(RSDs) were in the range of 3~5%, and the recoveries were from 84% to 97%. These indicated that methods were accurate and ensured reliable results.(2) The average concentrations of formaldehyde in raw liquors(n = 93) and finished liquors(n = 36) were 1.43 mg?L-1 and 0.893 mg?L-1, respectively. The levels of formaldehyde in 15 raw liquors(16%) and 3 finished liquors(0.09%) were more than 2.60 mg?L-1(IPCS tolerable concentration). Formaldehyde were formed during distillation and aging process. The levels of 1,1-diethoxymethane increased with time and their correlations with age were high(R2 > 0.6). Thus, 1,1-diethoxymethane could be used as age markers in Chinese raw liquor.(3) The average concentration of acetaldehyde in raw and finished liquors were 215 mg?L-1 and 173 mg?L-1, respectively. The content ratios of acetaldehyde and acetal were 0.840:1~2.87:1 and 1.24:1~1.96:1, respectively. During distillation process, acetaldehyde might be formed by hydrolysis of acetal.(4) The average concentrations of acrolein in raw liquors(n = 93) and finished liquors(n = 36) were 115 μg?L-1 and 72.3 μg?L-1, respectively. Both of them were far below World Health Organization(WHO) tolerable concentration of 1500 μg?L-1 and below that in other distilled spirit from different countries. The contents of acrolein increased during distillation, conversely, an decrease of acrolein levels was detected during liquor aging.(5) The margin of exposures(MOEs)of formaldehyde, acetaldehyde and acrolein were calculated to be 48300, 627 and 9320 in Chinese finished liquor, respectively. Acetaldehyde and acrolein in Chinese liquor should be of great concern. In view of comprehensive intake, it is necessary to reduce the contents of formaldehyde, acetaldehyde and acrolein in Chinese liquor, and set corresponding limit standards.