title: Investigation of volatile organic metabolites in lung cancer pleural effusions by solid-phase microextraction and gas chromatography/mass spectrometry.
abstract: Headspace solid-phase microextraction (HS-SPME) combined with gas chromatography/mass spectrometry (GC/MS) method was applied for the investigation of low molecular weight volatile organic metabolites (VOMs) in pleural effusion samples. Three important HS-SPME experimental parameters that influence extraction efficiency (fiber coating, extraction time and temperature of sampling) were optimized by a univariate optimization design. The highest extraction efficiency was obtained when sampling was performed at 50°C for 10min under agitation using a carboxen/polydimethylsiloxane (CAR/PDMS) fiber. A total of 36 volatile metabolites belonging to nine distinct chemical classes were identified in 40 pleural effusion samples (20 malignant effusions from lung cancer patients and 20 benign effusions from inflammatory patients). Ketones, alcohols, and benzene derivatives were the main chemical classes for the metabolomic profile of malignant effusions. The average peak areas of ketones and alcohols were much higher in malignant group compared to benign group. Together with phenols, they exhibit significant differences (P<0.05) between the two groups. Particularly, the average peak areas of cyclohexanone and 2-ethyl-1-hexanol in malignant effusions were significantly higher than those in benign ones. Furthermore, of the 36 identified metabolites, 5 compounds including cyclohexanone and 2-ethyl-1-hexanol were found to be statistically different (Student's t-test, P<0.05) between the two groups by statistical analysis based on the peak areas of all identified metabolites. Among them, cyclohexanone and 2-ethyl-1-hexanol might be considered as candidate biomarkers of lung cancer to differentiate malignant from benign effusions. The results show that HS-SPME-GC/MS is a simple, rapid, sensitive and solvent-free method for the determination of VOMs in pleural effusion samples. Pleural effusion is a valuable sample source for observation of changes in VOMs for differentiation between lung cancer patients and inflammatory individuals.
authors: College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014, China.
authors: Huijun
authors: H
authors: Liu
authors: Respiratory Department, Zhejiang Provincial People's Hospital, Hangzhou 310014, China.
authors: Hong
authors: H
authors: Wang
authors: College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014, China.
authors: Caixia
authors: C
authors: Li
authors: College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014, China.
authors: Lichao
authors: L
authors: Wang
authors: College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014, China.
authors: Zaifa
authors: Z
authors: Pan
authors: College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014, China. Electronic address: lili_wang@zjut.edu.cn.
authors: Lili
authors: L
authors: Wang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D000441:Hexanols / Q000032:analysis*; D006801:Humans; D008175:Lung Neoplasms / Q000737:chemistry / Q000150:complications* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000150:complications* / Q000473:pathology; D016066:Pleural Effusion, Malignant / Q000150:complications* / Q000473:pathology; D052617:Solid Phase Microextraction / Q000379:methods; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000441:Hexanols; D055549:Volatile Organic Compounds; C034017:2-ethylhexanol
keywords: Gas chromatography/mass spectrometry; Lung cancer; Pleural effusions; Solid-phase microextraction; Volatile organic metabolites (VOMs)