Quantitative Determination Of Volatile Components Such As Mineral Oil And Aroma Chemical In Food By GLME-GC/GC-MS

Food detection is generally divided into two parts: pre-processing and instrumental analysis.With the continuous development of society,food analysis technology is more and more advanced.However,pre-processing technology still has problems such as long time-consuming and cumbersome operation.In this paper,gas-liquid microextraction(GLME)instrument developed by Yanbian University is used to pre-treat mineral oil,food flavors and essences in some foods,which shortens the time-consuming problem compared with conventional food pretreatment technology.It has been found through experiments that the time taken to pre-treat mineral oil,flavors and essences in some foods by gas-liquid microextraction(GLME)instrument is more than half of the time-consuming reduction of conventional food pretreatment techniques.A method for the rapid detection of saturated hydrocarbon mineral oil in edible vegetable oil by gas-liquid microextraction(GLME)combined with gas chromatography(GC-FID)was established.After the sample is purified by gas-liquid microextraction,it is directly detected by gas chromatography.The parameters of gas-liquid micro-extraction equipment,including the amount of sample,the dilution ratio of the sample,the temperature of the heating bath and the extraction time,were investigated.The results showed that the sample loading was 50 ?L,the sample dilution ratio was 1:9,the heating bath temperature was 300 °C,and the extraction time was 5 min.The linearity of saturated hydrocarbon mineral oil in the range of 0.1~50 mg/L was good,the correlation coefficient was 0.9998,and the detection limits and quantification limits were 0.3 mg/kg and 1.0 mg/kg,respectively.Adding low,medium and high concentrations of saturated hydrocarbon mineral oil to edible vegetable oil,each spiked level was measured 5 times in parallel,and the average spiked recovery was between 88.6% and 117.2%,and the relative standard deviation(RSD)was 1.8%.Between 8.7%,the experiment proves that the method is easy to operate and fast,and its sensitivity and repeatability are in line with the testing requirements.Nine commercially available vegetable oil samples were tested by the established method.The results showed that all the 9 samples contained a certain amount of saturated hydrocarbon mineral oil,and the content was between 14.84 and 48.32 mg/kg.Volatile or semi-volatile components such as synthetic perfumes in seven essence samples were extracted by gas-liquid microextraction pretreatment,and qualitative analysis was performed by GC-MS.The essence samples is dissolved by solvent,purified by gas-liquid microextraction,and directly separated by gas chromatography-mass spectrometry(GC-MS).Gas-liquid micro-extraction(GLME)instrument setting conditions: heating bath temperature 280 °C;extraction time 4 min;nitrogen flow rate 2 m L·min-1;condensation temperature 0 °C.The saturated hydrocarbon mineral oil component of quasi-determined n-C16~n-C32 was searched by combining standard solutions and libraries of saturated hydrocarbon minerals.The results showed that the tested flavor samples contained n-C16~n-C32 saturated hydrocarbon mineral oil components.In addition,the chromatographic peaks in the total ion chromatogram are qualitatively analyzed by means of library search and manual deconvolution,and the main chromatographic peaks retrieved are qualitatively analyzed according to the information such as the similarity of the search,and the matching degree with the chromatographic peak is retrieved.Higher compounds were analyzed for finishing.The results showed that thirty-two different volatile or semi-volatile peaks were identified in seven flavor samples,including ten ester peaks,four sugar peaks,four aldehyde peaks,four phenol peaks,three ketone peaks,and three nitrogen-containing compound peak,a sulfur-containing compound peak,an ether peak,an aromatic peak,and an alcohol peak.The qualitative results of 13 peaks are shown as aroma chemical ingredients,and the FEMA number can be found in the list of aroma chemicals GB 2760-2014.Volatile or semi-volatile components such as synthetic perfumes in ten samples of hot strips were extracted by gas-liquid microextraction pretreatment,and qualitative analysis was performed by GC-MS.Gas-liquid micro-extraction(GLME)instrument setting conditions: heating bath temperature 300 °C;extraction time 6 min;nitrogen flow rate 2 m L·min-1;condensation temperature-4 °C.The saturated hydrocarbon mineral oil component of quasi-determined n-C17~n-C32 was searched by combining standard solutions and library of saturated hydrocarbon minerals.The results showed that the tested fragrance samples contained n-C17~n-C32 saturated hydrocarbon mineral oil components.In addition,qualitative analysis is performed on the chromatographic peaks in the total ion chromatogram of the number LT006 combined with the library search and manual deconvolution,and the main chromatographic peaks retrieved are qualitatively analyzed based on the information such as the search similarity,and the retrieved compounds with high chromatographic peak matching were analyzed.The results showed that the Spicy strip sample(LT006)identified 19 chromatographic peaks,including 5 ester peaks,5 alcohol peaks,4 hydrocarbon peaks,3 aldehyde peaks,1 nitrogen-containing compound peak,and 1 ketone peak.The qualitative results of 12 peaks are shown as aroma chemical ingredients,and the FEMA number can be found in the list of aroma chemicals GB 2760-2014.