Measurement of diallyl disulfide and allyl methyl sulfide emanating from human skin surface and influence of ingestion of grilled garlic.

Diallyl disulfide (DADS) and allyl methyl sulfide (AMS) have been known as a metabolic product of sulfur-containing foods, typically garlic. The odour of such organosulfur compounds following garlic ingestion is often considered as an unpleasant element. Although previous studies have identified the DADS and AMS associated with garlic breath, no study has been reported on the determination of both compounds emanating from human skin surface. This study aimed to demonstrate the effect of garlic ingestion on the dermal emissions of DADS and AMS using a passive flux sampler coupled with gas chromatography-mass spectrometry. Firstly, baseline levels were investigated for 30 healthy volunteers in their daily life. The results of 1 h-sampling at the forearm showed the emission fluxes of both compounds followed the lognormal distribution with a geometric mean of 0.18 ng cm-2 h-1 for DADS and 0.22 ng cm-2 h-1 for AMS. Subsequently, the garlic ingestion tests were conducted for selected volunteers. The emission flux of DADS increased just after grilled garlic ingestion and decreased gradually thereafter. In contrast, the dermal emission flux of AMS reached a peak at 30 min after ingestion, and then gradually decreased. This peak shift suggests AMS is relatively latent in the skin organs.

Detection of tobacco smoke emanating from human skin surface of smokers employing passive flux sampler - GCMS system.

Cigarette smoking is a significant risk factor for higher incidences of numerous adverse health consequences. Related health disorders are also found in non-smokers exposed to secondhand smoke (SHS). To investigate the influence of cigarette smoking and exposure to SHS on the composition of human skin gas, a trace biogas emanating from human skin, dermal emissions of volatile compounds were semi-quantitatively measured for volunteers who smoke a cigarette and those exposed to SHS. This was performed using a passive flux sampler (PFS) coupled with gas chromatography mass spectrometry (GCMS). Numerous chemicals were detected, including acetaldehyde, toluene, 3-methyl furan (3-MF), 2,5-dimethyl furan (2,5-DMF), 3-ethenyl pyridine (3-EP), and nicotine, in the samples collected from the smokers after a smoking event, and a remarkable increase in the amount of chemicals collected was observed just after smoking. These chemicals were also found in the samples collected from volunteers exposed to SHS. Assessment of current smoking status is important for managing the negative effects of active and passive smoking, and for the development of public health policy. The tobacco specific chemicals such as 3-MF, 2,5-DMF, 3-EP, and nicotine, emanating from human skin surfaces, represent a potential non-invasive biomarker for monitoring current smoking status of active and passive smokers after establishing a more quantitative procedure.