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    Chinese Journal of Chromatography
    2018, Vol. 36, No. 8
    Online: 08 August 2018

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    Research progress of micro-electro-mechanical systems micro gas chromatography columns
    LUO Fan, FENG Fei, ZHAO Bin, TIAN Bowen, YANG Xuelei, ZHOU Haimei, LI Xinxin
    2018, 36 (8):  707-715.  DOI: 10.3724/SP.J.1123.2018.02015
    Abstract ( 483 )   [Full Text(HTML)] () PDF (5185KB) ( 168 )  

    The gas chromatography (GC) column is a key component of the gas chromatographic system, which is mainly used for the separation of mixed gas components. Compared with the traditional GC column, the micro GC column based on micro-electro-mechanical systems (MEMS) technology has the advantages of lighter weight, smaller volume, lower power consumption, and faster analysis. Furthermore, it can be integrated into a portable instrument, such as a miniaturized GC. The research progress of micro GC columns based on MEMS technology is summarized in this paper. First, the theoretical basis of the MEMS micro GC column is stated. Then, the layout and inner structure of the MEMS micro GC column, the stationary-phase support, and the preparation of the stationary phase are summarized. Finally, trends in the development of MEMS micro GC columns are discussed.

    Preparation of magnetic surface molecularly imprinted polymers for melamine and its application in milk samples
    SUN Zhi'an, QI Yuxia, WANG Xia, ZHOU Yanqiang, GONG Bolin
    2018, 36 (8):  716-722.  DOI: 10.3724/SP.J.1123.2018.03033
    Abstract ( 489 )   [Full Text(HTML)] () PDF (3154KB) ( 140 )  

    By using melamine (MEL) as the template molecule, magnetic surface molecularly imprinted polymers (MMIPs) were prepared. Methacrylic acid (MAA) was chosen as the functional monomer, and ethyleneglycol dimethacrylate (EGDMA) was chosen as the cross-linker, and Fe3O4@SiO2 was used as the magnetic supporter. Transmission electron microscope (TEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) analysis and a vibrating sample magnetometer (VSM) were used to characterize the polymers. An imprinted polymer layer was found on the surface of the Fe3O4@SiO2 nanomaterials. MMIPs were applied to extract and enrich melamine in milk samples. The specific recognition capability of the material was confirmed by high performance liquid chromatographic (HPLC) analysis. Thus, a simple and selective method was successfully established using MMIPs as sorbents to detect melamine in milk with satisfactory results.

    Synthesis and application of a magnetic spiramycin-templated molecularly imprinted nanoparticle adsorbent
    SUN Jiajia, ZHANG Feifang, LIANG Xinmiao
    2018, 36 (8):  723-729.  DOI: 10.3724/SP.J.1123.2018.03034
    Abstract ( 431 )   [Full Text(HTML)] () PDF (4314KB) ( 124 )  

    A magnetic spiramycin-templated molecularly imprinted nanoparticle adsorbent is described. It was synthesized by choosing Fe3O4 nanoparticles as the core, and then modified with acrylic acid, followed by the addition of spiramycin as a template molecule, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a crosslinking agent. Finally, the adsorbent was prepared via surface radical polymerization. The adsorbent demonstrated effective enrichment for four macrolide antibiotics (MA) including spiramycin, josamycin, tilmicosin, and tylosin tartrate, whose enrichment factors were 310, 118, 758, and 72, respectively. Its selectivity toward the trace MA was obviously higher than that of the common C18 adsorbent. In addition, the adsorbent also showed favorable reusability (at least six times). A corresponding analytical method for MA was established by subjecting the adsorbent to high-performance liquid chromatography with ultraviolet absorbance. For the above four model MAs, the limits of detection were in the range of 0.53-2.75 μg/L, and the limits of quantitation were in the range of 1.78-9.16 μg/L. The recoveries of the method were in the range of 80.78%-123.02% for three spiked levels of 50, 100 and 150 μg/L, and the relative standard deviation was less than 15.8% (n=5). The method was used for the determination of the four MAs above in honey.

    Simultaneous determination of 11 strobilurin fungicides in different vegetation types of soil by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry
    WANG Lu-fang, LI Chun-mei, XU Jiabin, LI Hui, SU Hang, WANG Jing, JIN Fen, ZHANG Yu
    2018, 36 (8):  730-737.  DOI: 10.3724/SP.J.1123.2018.02020
    Abstract ( 410 )   [Full Text(HTML)] () PDF (3218KB) ( 103 )  

    A method for the simultaneous determination of the 11 strobilurin fungicides (coumoxystrobin, tricyclopyricarb, picoxystrobin, fluoxastrobin, trifloxystrobin, E-metominostrobin, kresoxim-methyl, dimoxystrobin, orysastrobin, pyraoxystrobin and fenaminstrobin) in different vegetation types of soil by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry was developed. The strobilurin fungicides were extracted with 0.1% (volume percentage) acetic acid-acetonitrile, and cleaned-up with 100 mg primary secondary amine (PSA) and 100 mg C18. The separation was performed on a C18 column with methanol and water as the mobile phases. The strobilurin fungicides were determined in the positive ion mode and multiple reaction monitoring mode. The quantification was carried out by the matrix-matched external standard curve. The results showed good linear relationships for all analytes in the range of 0.1-100 μg/kg with the correlation coefficients of 0.9805-0.9999. The mean recoveries of strobilurin fungicides in the spiked soil samples were 65.1%-103.9% and the relative standard deviations were 0.082%-14% (n=3) at three spiked levels (5, 10 and 50 μg/kg). The limits of quantitation were 0.005-2.0 μg/kg. This method is suitable for the trace determination of the 11 strobilurin fungicides in different vegetation types of soil (black soil, red soil, sandy soil, moisture soil, desert grey soil, and plateau soil).

    Rapid determination of fipronil and its metabolite residues in eggs using ultra performance liquid chromatography-tandem mass spectrometry
    ZHANG Aizhi, LI Xiangjiang, WANG Zhiqiang, ZHANG Shufen, SONG Yue, CAO Lili, CAI Juemei, CHEN Linji
    2018, 36 (8):  745-751.  DOI: 10.3724/SP.J.1123.2018.03012
    Abstract ( 384 )   [Full Text(HTML)] () PDF (1612KB) ( 96 )  

    A method was developed for the rapid simultaneous determination of fipronil and its metabolite residues in eggs using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The egg samples (2 g) with 2 mL water were extracted with 4 mL acetonitrile. After adding 1 g sodium chloride, the mixture was centrifuged at 9000 r/min for 10 min at 4℃. The suspension was diluted and filtered through a 0.22 μm organic membrane. The analytes were separated on a C18 column (100 mm×2.1 mm, 1.7 μm), and detected under the multiple reaction monitoring (MRM) mode with a negative ESI source. The average recoveries of fipronil and its metabolites varied from 77.4% to 112.1%, and the relative standard deviations were between 4.0% and 13.6% at three spiked levels. The limits of detection (LODs) ranged from 0.10 μg/kg to 0.43 μg/kg. The method is simple, effective, and can be applied to real samples.

    Simultaneous determination of monepantel and its metabolite residues in cow and sheep milk by solid phase extraction-high performance liquid chromatography-tandem mass spectrometry
    WU Yingxuan, XIE Minling, YAO Yangxun, LAN Cao
    2018, 36 (8):  752-757.  DOI: 10.3724/SP.J.1123.2018.03014
    Abstract ( 426 )   [Full Text(HTML)] () PDF (867KB) ( 59 )  

    A method for the rapid and simultaneous determination of monepantel and its metabolite residues in cow and sheep milk has been developed using high performance liquid chromatography-tandem mass spectrometry. The samples were extracted with acetonitrile to precipitate the proteins and passed through a neutral alumina solid phase extraction (SPE) cartridge. The extracts were separated on an Inertsil C8-3 column (150 mm×4.6 mm, 5 μm) with a gradient elution program consisting of methanol and ammonium acetate. A triple stage quadrupole mass spectrometer equipped with an electrospray ionization source in negative ion mode was used to detect monepantel and its metabolite residues. The quantification of the analytes was performed by the external standard method. Good linear relationships between the peak areas and mass concentrations of the analytes were obtained in the range of 0.1-5.0 μg/L with correlation coefficients greater than 0.99 (n=6). The limits of quantification were 2.0 μg/kg. The recoveries of the analytes in cow and sheep milk at three spiked levels (2.0, 50, and 100 μg/kg) were in the range of 90.1%-103.3% with relative standard deviations between 2.0% and 6.2% (n=6). This method is fast, accurate, and highly sensitive, exhibits strong anti-interference capability with good recovery and repeatability, and can thus be used to simultaneously determine monepantel and its metabolite residues in cow and sheep milk.

    Determination of 28 exogenous medicines and endogenous components in herbal drink using high performance liquid chromatography
    HE Jiawen, WEN Jiaxin, LAI Yuhong, CAO Yajing
    2018, 36 (8):  758-765.  DOI: 10.3724/SP.J.1123.2018.02005
    Abstract ( 361 )   [Full Text(HTML)] () PDF (895KB) ( 43 )  

    A high performance liquid chromatographic method for the determination of 28 exogenous medicines and endogenous components in the herbal drink was developed. The samples were extracted ultrasonically with methanol-water (70:30, v/v), and the extracts were separated in a Thermo Accucore C18 column (100 mm×4.6 mm, 2.6 μm) with methanol-acetonitrile-20 mmol/L ammonium acetate solution (pH 4.2) as the mobile phases by gradient elution. The flow rate was 1.2 mL/min and the column temperature was 35℃. The detection wavelengths were 254 nm and 220 nm. Quantification analysis was performed by the external standard method. The result showed the compounds had a good linear relationship in the range of 1-100 mg/L, and the correlation coefficients (r) were not less than 0.999. The limits of detection (LODs) of the 28 compounds were 1-10 mg/kg in the liquid sample and 20-200 mg/kg in the solid sample. The average recoveries of the 28 compounds in the liquid and solid samples were in the ranges of 88.8%-118.6% and 92.7%-112.3% with the relative standard deviations (RSDs) of 0.1%-6.7% and 0.1%-6.4%, respectively. The method was applied to analyze 456 herbal drink samples, and 55 positive samples were found. The positive rate was 12.1%. The developed method was simple and reliable, and it was suitable for the determination of 28 components in the herbal drink.

    Analysis of traditional Chinese medicine components by high performance liquid chromatography with diode array detection based on double qualitative principles
    TANG Tao, YANG Sandong, ZHAO Haiqing, TAN Yimeng, FENG Jiao, XIA Mingzhu, LI Tong
    2018, 36 (8):  766-771.  DOI: 10.3724/SP.J.1123.2018.02012
    Abstract ( 347 )   [Full Text(HTML)] () PDF (1324KB) ( 109 )  

    The double qualitative principle is a new composite qualitative method based on retention time and the characteristic peaks of the absorption spectra. Using a self-designed and assembled diode array detector (DAD), a high performance liquid chromatography (HPLC) system was constructed. The illegal additive auramine O in six kinds of herbal slices and the active ingredient schisandrin in Jujube kernel Tianma capsules were separated and qualitative analyzed using the HPLC-DAD system. The results showed that there were similar peaks in the chromatograms of pollen typhae and Jujube kernel Tianma capsules when comparing the target analytes. However, the probabilities of the targets were excluded by comparing the absorption spectra. The application results indicated that, based on the double qualitative principle of retention time/absorption spectrum, the interference of impurities in the samples could be well eliminated and the false positives could be avoided. This provides a reference method for the study of traditional Chinese medicine components.

    Gas chromatography-mass spectrometry data analysis algorithm based on sparse model and its application in resolving severely overlapped peaks
    WU Yizi, WEI Weiwei, YANG Huawu, CHEN Zengping, ZOU You, LI Yanchun, TUO Suxing, YIN Shuangfeng, ZHONG Kejun
    2018, 36 (8):  772-779.  DOI: 10.3724/SP.J.1123.2018.03001
    Abstract ( 292 )   [Full Text(HTML)] () PDF (2447KB) ( 48 )  

    A Gas chromatography-mass spectrometry (GC-MS) data analysis algorithm is proposed. The mass spectrum at the top of the chromatographic peak is the spectrum to be solved. A certain amount of related reference spectra is retrieved from the spectral library, then, the equation of the chromatographic response value of each pure component is solved. A step by step strategy is used for the mass spectra retrieval. Firstly, an efficient indexing technology is used for rough selection, then, the "strong peak out with high probability" and the "extrusion" rules are used to exclude more unrelated mass spectra. A regression algorithm based on a sparse model is proposed to solve the equation of the chromatographic response value. Compared with the traditional algorithm, this algorithm can extract the main structure of the spectrum to be solved, and avoid over-fitting. The experimental results show that the proposed algorithm has a higher accuracy and smaller residual reference spectrum set, and the sparse model achieves satisfactory experimental results in the analysis of severely overlapped peaks. The proposed method provides an effective solution for resolving overlapped peaks, especially severely overlapped peaks, in GC-MS data.

    Analysis of kerosene-based endothermic hydrocarbon fuel using comprehensive two-dimensional gas chromatography coupled to mass spectrometry
    LI Haijing, LIU Guozhu, ZHANG Xiangwen
    2018, 36 (8):  780-785.  DOI: 10.3724/SP.J.1123.2018.02030
    Abstract ( 302 )   [Full Text(HTML)] () PDF (1556KB) ( 127 )  

    Hydrocarbon fuels are mainly composed of n-alkenes, iso-alkanes, cycloalkanes (primarily single-and double-ring), alkylbenzenes, indans, tetralins, naphthalene, and alkylnaphthalenes. Different hydrocarbon classes impart different properties to a fuel. An identification method of hydrocarbon classes in kerosene-based endothermic hydrocarbon fuel was established using comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS). Moreover, the corresponding quantitative determination was achieved using the effective carbon number correction factors of GC×GC-FID. The effects of the main chromatographic conditions such as the column system, program heating conditions, and modulation period on the separation of fuels were discussed. Nine hydrocarbon fuels were analyzed. The results showed that the contents of paraffin and cycloalkanes are consistent with the results obtained using the standard test method ASTM D2425. The relative error is within ±10%. The carbon content calculated using this method has an error of less than 0.5% compared with the elemental analysis method. This method does not require complicated pretreatment, and the sample can be injected directly after dilution. Compared with the traditional GC-MS, the operation is simple, and the differences among various samples can be observed intuitively, which helps in improving the performance of the fuel.

    Determination of 16 phthalate acid esters in infant formula by gas chromatography-tandem mass spectrometry
    XU Bingbing, LI Xiaomin, ZHANG Qinghe, ZHU Weihuang
    2018, 36 (8):  786-794.  DOI: 10.3724/SP.J.1123.2018.03010
    Abstract ( 404 )   [Full Text(HTML)] () PDF (2655KB) ( 123 )  

    A method was established for the determination of 16 phthalate acid esters (PAEs) in infant formula by gas chromatography-tandem mass spectrometry (GC-MS/MS). PAEs in infant formula samples were homogenized by deionized water, extracted with acetonitrile, and purified by a solid-phase extraction (SPE) method using primary secondary amine (PSA) sorbents. The separation was performed on a DB-5 MS UI (30 m×0.25 mm×0.25 μm) capillary column. Effects of different elution solvents on alumina/PSA and PSA SPE columns were investigated. Fair recoveries of 16 PAEs were achieved on the PSA column upon elution by mixed n-hexane-acetone (60:40, v/v). All the 16 PAEs were quantified by matrix-matched isotopic-dilution mass spectrometry (IDMS); the 16 PAEs showed linear relationships in the concentration range of 0.01-2.0 mg/kg with linear coefficients (R2) greater than 0.9996. The limits of detection (LODs) and quantification (LOQs) were in the range of 0.15-2.5 μg/kg and 0.50-8.33 μg/kg, respectively. The recoveries of the 16 PAEs, obtained using the IDMS method, were 96.1%-104.0% with relative standard deviations (RSDs) lower than 3.3% (n=5). These results established the method described here as sensitive and precise for the simultaneous determination of 16 PAEs in infant formula, even at trace concentrations.

    Determination of 11 synthetic musks in imported seafood by solid phase extraction and gas chromatography-mass spectrometry
    QU Li, ZENG Jing, ZHAO Chaomin, SONG Weimin
    2018, 36 (8):  795-802.  DOI: 10.3724/SP.J.1123.2018.02022
    Abstract ( 383 )   [Full Text(HTML)] () PDF (1909KB) ( 95 )  

    A method has been developed for the simultaneous determination of 11 synthetic musks (cashmeran, celestolide, phantolide, musk ambrette, traseolide, galaxolide, musk xylene, tonalide, musk moskene, musk tibetene, and musk ketone) in imported seafood. The method combines solid phase extraction and gas chromatography-mass spectrometry. Samples were extracted by n-hexane and purified using a Florisil column. Internal standards were used to correct for matrix effects. The calibration curves showed good linearity with correlation coefficients greater than 0.99. The limits of detection (S/N>3) ranged from 0.35 to 2.08 μg/kg, and the limits of quantification (S/N>10) were between 1.18 and 5.00 μg/kg. The average recoveries measured at three spiked levels (10, 20, and 30 μg/kg) were in the range 83.1%-117%, with relative standard deviations ranging from 5.1% to 8.5%. Further, the concentrations of 11 synthetic musks in 30 imported seafood in Shanghai were investigated. Galaxolide was detected in 93.3% of samples analysed, in concentration as high as 3.82 μg/kg. Musk ambrette and musk moskene were found in concentrations as high as 15.4 μg/kg and 10.5 μg/kg, respectively. The established method demonstrates high sensitivity and selectivity for the determination and confirmation of 11 synthetic musks in imported seafood.

    Determination of six amphetamine-type stimulants in urine samples using electro-enhanced single drop microextraction-gas chromatography
    SONG Aiying, YANG Jing
    2018, 36 (8):  803-808.  DOI: 10.3724/SP.J.1123.2018.03021
    Abstract ( 259 )   [Full Text(HTML)] () PDF (1004KB) ( 55 )  

    A method for the simultaneous determination of six amphetamine-type stimulants (ATSs) in urine by electro-enhanced single drop microextraction-gas chromatography (EE-SDME-GC) with a flame ionization detector (FID) was developed. The influences of the EE-SDME parameters on the extraction efficiencies were investigated. The 5 mL-samples at pH 7 were extracted with 2 μL dichloromethane for 3 min under an applied potential of -2.5 V. The analysis was performed on a HP-5 capillary column (30 m×0.32 mm×0.25 μm) using a flame ionization detector. The six ATSs were linear in the range of 20-1000 μg/L with correlation coefficients (r) between 0.989 and 0.997. The limits of detection (S⁄N=3) of the six ATSs ranged from 3.2 to 7.6 μg/L. The recoveries of the six ATSs in the spiked urine samples were 91.6%-111.2%, and the relative standard deviations were 2.9%-6.2% (n=3) at three spiked levels of 50, 100 and 500 μg/L. This method was rapid, sensitive, reliable, easily-operated and environment-friendly for the determination of the ATSs in urine samples.

    Screening of 17 cephalosporin residues in infant formula milk powder by ultra-high performance liquid chromatography-high resolution mass spectrometry
    CHENG Jianqiao, ZHANG Feng, XU Xiuli, HONG Yunhe, WU Hanqiu, WANG Chuansheng
    2018, 36 (8):  809-816.  DOI: 10.3724/SP.J.1123.2018.02014
    Abstract ( 349 )   [Full Text(HTML)] () PDF (896KB) ( 121 )  

    A method for the simultaneous determination of 17 cephalosporinsin milk powder by ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) has been developed. After dissolution in water, the homogenized milk powder samples were extracted with acetonitrile to remove impurities such as proteins and the extract was further purified by high-speed centrifugation at low temperature. A C8 chromatographic column was employed to separate the analytes. Quantitative and qualitative analyses were performed in Q Exactive Full-MS/dd-MS2 scan mode. The results revealed an excellent linear correlation over a wide range of analyte mass concentrations (5-200 μg/L) with coefficients of determination (r2) greater than 0.99 in all cases. The limits of detection (LODs) and quantitation (LOQs) were in the range of 0.0060-0.014 μg/L and 0.71-4.62 μg/kg, respectively. The overall average recoveries were 69.6%-101.4% with RSDs<10%. This method presents the advantages of simple operation, good repeatability, and high resolution, being suitable for the qualitative and quantitative screening of 17 cephalosporin residues in infant formula milk powder.

    Determination of aminobutanol by high performance liquid chromatography based on charge transfer reaction
    SHAO Meiqi, CHEN Yan, PENG Qing, LIU Pengfu, WU Jiequn, CHU Xiaohe
    2018, 36 (8):  817-821.  DOI: 10.3724/SP.J.1123.2018.03026
    Abstract ( 368 )   [Full Text(HTML)] () PDF (853KB) ( 76 )  

    A method was developed for the determination of the content of aminobutanol by high performance liquid chromatography (HPLC) based on charge transfer reaction. Under the condition of a borax-boric acid buffer solution of pH 8.4, aminobutanol and tetra-chloro-benzoquinone reacted at 60℃ for 60 min, and were analyzed by an HPLC-ultraviolet detector. The charge-transfer complex was separated on an Agilent Extend C18 column (250 mm×4.6 mm, 5 μm) with 0.001% (v/v) triethylamine and methanol as the mobile phases for gradient elution at a flow rate of 1 mL/min. The limit of quantification of aminobutanol was 0.01 g/L, the linear range was 0.1-0.6 g/L, and the correlation coefficient (R2) was 0.9994. The spiked recoveries of the method were 98.3%-103.6% with relative standard deviations (RSDs) of 0.9%-1.6%. The method is simple and quick, and suitable for the rapid detection of aminobutanol.

    Fabrication of conventional ion chromatography-capacitively coupled contactless conductivity detector
    CHEN Xiaohua, HOU Yanjie, YANG Bingcheng, AI Lei
    2018, 36 (8):  822-826.  DOI: 10.3724/SP.J.1123.2018.03011
    Abstract ( 312 )   [Full Text(HTML)] () PDF (1026KB) ( 95 )  

    A conventional ion chromatography-capacitively coupled contactless conductivity detector (IC-C4D) was fabricated. The main parameters, such as the electrode length and gap, tube material and inner diameter, excitation frequency, voltage and waveforms, were optimized. The self-made C4D showed comparable performance to that of a commercial contact conductivity detector. Under the suppressed mode, the limits of detection of common inorganic anions (F-, Cl-, NO2-, Br-, NO3-, and SO42-) were 0.02-0.08 μmol/L. The relative standard deviations (RSDs) for the peak area were less than 1.8% (n=6). The linearities of the six common inorganic anions were achieved in the range of 0.1-10 μmol/L with correlation coefficients (R2)>0.9950. The advantages of such a C4D in a relatively conventional mode include simple structure, low fabrication cost and no electrode fouling, and it will help extend the application of IC.

    Differences of three pretreatment methods for the detection of docosahexaenoic acid, eicosatetraenoic acid, linoleic acid and α-linolenic acid in infant formula milk powder
    LI Jie, JU Xiang, WANG Yanli, TIAN Qiyan, SHEN Zhonglan, HU Mei, LIU Yanming, ZHU Jianhua
    2018, 36 (8):  827-832.  DOI: 10.3724/SP.J.1123.2018.03019
    Abstract ( 348 )   [Full Text(HTML)] () PDF (1257KB) ( 94 )  

    The differences of three pretreatment methods (acetyl chloro carbinol esterification, acid hydrolysis esterification and alkali hydrolysis esterification) for the detection of four polyunsaturated fatty acids (docosahexaenoic acid, arachidonic acid, linoleic acid and α -linolenic acid) in infant formula milk powder were discussed. Acetyl chloro carbinol esterification and acid hydrolysis esterification were found to be significantly better than alkali hydrolysis esterification. The sample digestion and fat methyl esterification were carried out simultaneously in the acetyl chloro carbinol esterification method, where the two processes seemed to enhance each other. This allowed the complete release and methyl esterification of the fats. The accuracy of the methods was determined by investigating the reaction processes and recovery rates. Acid and alkali hydrolysis esterification methods were employed to hydrolyze the samples using a hydrochloric acid solution and an ammonia solution, respectively. Then, the fats were extracted for subsequent methyl esterification. These two methods were compared in terms of the digestion efficiency, extraction efficiency, and methylation efficiency. The results showed that the digestion efficiency is the main factor determining the differences between the acid and alkali hydrolysis methods. The accuracies of acetyl chloro carbinol esterification and acid hydrolysis esterification methods were further verified in the detection of samples, providing a basis for the determination of fatty acids in other foods.