Research Of Chromatographic Analysis Method Of Main Organic Additives And Organic Acids In PBAT Biodegradable Mulch Films

1.A method based on the application of microwave-assisted extraction(MAE)and dispersive liquid–liquid microextraction(DLLME)was developed to analyze eighty organic additives by gas chromatography-mass spectrometry(GC-MS)in poly(butylene adipate terephthalate)(PBAT)biodegradable films.The identification of organic additives,optimization of MAE and DLLME methods,analysis of isocyanate conversion,and evaluation of the matrix effect(ME)were evaluated.Under the optimized experimental conditions,this method exhibited excellent detection capabilities for organic additives,except for 5kinds of isocyanates and their reaction products,with coefficients of determination R²>0.999 and lack of fit P>0.05 in linear regression parameters.A negligible ME was observed.The relative recoveries were 93.0-109.8%,and the repeatability and reproducibility varied within the ranges of 2.06-8.76%and2.38-10.23%,respectively.The limits of detection and limits of quantitation were 0.0008-0.0586?g g^-1 and 0.003-0.195?g g^-1,respectively.The developed method was further successfully applied to the analysis of organic additives in PBAT biodegradable mulch films from four different manufacturers.Interestingly,the Venn diagram and principal component analysis showed that different manufacturing origins display obvious characteristic differences in the organic additive types and concentrations.2.A method for simultaneous and rapid analysis of organic acids in PBAT biodegradable films was established.The procedures included ultrasonic extraction with methanol,derivatization with sulfuric acid-methanol solution,enrichment with dispersion liquid-liquid micro-extraction,and then determination with gas chromatography-mass spectrometry(GC-MS).The results show:(1)The best extraction conditions are ultrasonic extraction time and temperature with 30 min and 50?,(2)The best derivatization conditions are5%sulfuric acid-methanol solution as derivatization reagent,derivatization time and temperature with 60 min and 90?,(3)The best dispersion liquid-liquid micro-extraction conditions are 125?L carbon tetrachloride as the extractant and methanol as the dispersant.(4)Fifty organic acids were detected with matching with the 2008 NIST Mass Spectral Library.The relative standard deviation was0.18%-14.46%.The method is simple to operation,short analysis time,and has the advantages of good reproducibility.It is suitable for high throughput determination of organic acid in PBAT biodegradable films.3.A method suitable for qualitative and quantitative analysis was established to determine the main volatile organic compounds(VOCs)in PBAT biodegradable films by headspace-solid phase microextraction(HS-SPME)combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry(GC×GC-TOF-MS).Effects of type of SPME fiber,equilibrium temperature,equilibrium time and extraction time on extraction efficiencies for VOCs in biodegradable films were investigated.Results indicated that 55 VOCs were identified and relatively quantified with polydimethylsiloxane-divinylbenzene-carboxen(PDMS-DVB-CAR)fiber at80?extraction temperature for equilibrium time of 10 min and extraction time of 40 min.The intra-and inter-day precision are both less than 20%with good stability and repeatability.The VOCs in 4 kinds of PBAT biodegradable films from different manufacturers were analyzed with multivariate statistical analysis.The PBAT biodegradable film from different manufacturers can be distinguished,and each biodegradable film has a characteristic difference,with higher benzene homologues for PBAT D and naphthalene,amines,phenol for PBAT A+B,while lower VOCs for PBAT C.This study can provide a scientific detection method for the safety evaluation and use of PBAT biodegradable film.