Analysis Of Volatile Organic Compounds In Pleural Effusion By Headspace Solid Phase Microextraction Gas Chromatography/Mass Spectrometry

Solid phase microextraction(SPME)is a sample preparation method,which integrates extraction,concentration,derivatization,desorption and injection into one step,and couples to chromatographic techniques.SPME-Gas Chromatography/Mass Spectrometry(GC/MS)can be used to analyze volatile compounds from complex samples such as biological and flavor samples.In this paper,HS-SPME-GC/MS was used for the analysis of volatile compounds in pleural effusion,and to look for markers of lung cancer,to guide the benign and malignant pleural effusion,in order to assist clinical diagnosis of cancer,especially lung cancer.Pleural effusion is the most specific body fluids of patients with lung disease.It's a reflection of many diseases of the body on the pleura,and it's directly attributable of lung disease closely with the development of the disease.We initially established a HS-SPME-GC/MS method for determination of volatile organic compounds in simulated samples,using a mixture of toluene,heptanal,cyclohexanone,decane,and iso-octanol.Single-factor experiment investigating the factors that influenceed the extraction efficiency was carried out.The best solid phase micro extraction conditions is described as follows:a fiber of 65 ?m PDMS/DVB,10 min of extraction time,50? of extraction temperature,250 r�min-1 of stirring speed,pH=7,2.0 mL of sample,250? of inlet temperature,1.0 min of desorption time,and 0.7 min splitless time.The method validations including linearity,detection limit,recovery and precision were studied.It was found that the above method provided a good linearity of calibration curve with the correlation coefficient of more than 0.994,low detection limits of 4.0%for toluene,7.4%for heptanal,4.8%for cyclohexanone,5.6%for decane and 4.8%iso-octanol,recoveries from 85.0%?112.3%(in blank)and 51.7%?132.5%(in pleural effusion),R.S.D.(%,n=8)values less than 7.4%.The obtained results show that the SPME-GC/MS is a simple,rapid,sensitive and solvent-free method for determination of volatile compounds from pleural effusion sample.In real samples of pleural effusion,we considered quadratic optimization to verify the detection results of the simulation sample.Convenience for sample's transporting and saving was also considered.The final method was applied in the detection of 78 pleural effusion samples.By gas chromatography/mass spectrometry,the NIST 2.0 mass library,combined with manual parsing,83 kinds of volatile organic compounds that have high matching degrees were detected.The results show that malignant pleural effusions than benign pleural effusion was detected in the more volatile substances.Through mathematical methods of statistics of SPSS software,we found 9 kinds of suspected lung cancer markers with statistical significance from 50 pieces of pleural effusion(Including 19 pleural effusion of lung cancer)that confirmed the cause of disease.Cyclohexanone and iso-octanol had better sensitivity,specificity,and predictive values that all reached about 80%.Besides,we got a judge model from the 9 VOCs,combined with cyclohexanone,isooctyl alcohol,acetophenone,2-phenyl-2-propanol and propionic acid.The model was applied to judge the known cases,its sensitivity,specificity,and predictive value were 90.0%,80.0%,92.3%and 75.0%,respectively.This method has the judgment potential of unknown pleural effusion of benign and malignant.which is expected to be applied to clinical diagnosis,and achieve early detection and early diagnosis of the tumor.