Application Research Of HPLC In Related Component Determination Of Concentrated Fruit Juices And Its Processing Aids

The polyphenols, amino acids and organic acids were the important compounds for evaluation of fruit quality, juice quality inspection and processing technology control index. At present we lacked of detection standards and methods for polyphenols, amino acids and organic acids. At the same time, there was no document about the determination of benzoic acid and sorbic acid of fruit juice processing enzyme and no report about the styrene and divinylbenzene of fruit juice processing resins at currently. At the present time, when the problem of food safety was concerned by the international community more and more, It was necessary to research methods of determination organic acids, amino acids and polyphenols in juices, styrene and divinylbenzene in juices and resins and benzoic acid and sorbic acid in enzyme for establish relevant quality control standards. The HPLC analysis was the most widely applied analytical technique for high separation efficiency and speed, high sensitivity, less sample consumption, easy combining with other instruments easy, once completed separation and determination.In this paper, we studied the methods for determinating benzoic acid and sorbic acid in enzyme and organic acids in juices by HPLC, styrene and divinylbenzene in juices and resins by UPLC and amino acids and polyphenols in juices by UPLC-MS/MS.The results were as follows:(1) Analytical method was developed to determinate benzoic acid and sorbic acid in enzyme using HPLC-DAD. ACE 5 C18 was analysis column. The mobile phase was 0.02 mol/L NH4Ac(pH 5.8) and methanol. The detection wavelength was 230nm.The results showed good linear relationship with good precision and accuracy at the range of 1.00～2.50×102μg/mL for benzoic acid and sorbic acid(r≥0.999). The average recoveries for all analytes were between 92.3%～109%. The RSD was lower than 3.1%(n=6).It was proved to be specific,accurate and convenient, which was suitable for analysis benzoic acid and sorbic acid in enzyme samples. The accurate and reliable results could be received within only 15 minutes.(2) Analytical method of SPE-RP-HPLC was developed to determinate organic acids in concentrated fruit juices. Aichrom BondAQ C18 was analysis column. The mobile phase were 0.02mol/L NH4H2PO4(pH 2.8) and methanol. The detection wavelength was 210nm. The results showed good linear relationship with good precision and accuracy at the range of 4.80×10-2～4.80mg/mL for tartaric acid,0.20～20.0mg/mL for quinic acid,0.10～10.0mg/mL for malic acid,0.01～1.00mg/mL for shikimic acid,0.02～2.00mg/mL for ascorbic acid, 0.40～40.0mg/mL for acetic acid,0.01～1.00mg/mL for maleic acid,0.20～20.0mg/mL for lactic acid, 0.20～20.0mg/mL for succinic acid,4.00×10-3～0.40mg/mL for fumaric acid and 0.10～10.0mg/mL for citric acid.The average recoveries for all analytes were between 80.1%-95.5%.The RSD was lower than 6.0%(n=6). It was proved to be small interfering impurities and good analysis result.(3) Analytical method of UPLC-PDA was developed to determinate styrene and divinylbenzene in concentrated fruit juice and resin samples. BEH C18 was analysis column. The mobile phase were water and acetonitrile. The liner gradient elution was applicated. The detection wavelength was 240nm. The results showed good linear relationship with good precision and accuracy at the range of 1.00～1.00×102μg/mL for styrene and divinylbenzene (r=0.9999).The average recoveries for juice samples were between 81.4%～88.4%. The RSD was lower than 3.6%(n=6). The average recoveries for resin samples were between 80.7%～90.7%. The RSD was lower than 3.7%(n=6).The method for preparation sample was easy and analysis speed was fast. The accurate and reliable results could be received within only 4min.(4) Analytical method of UPLC-MS/MS was developed to determinate polyphenols in concentrated fruit juices. The sample was extracted completely by SPE using Oasis MAX. BEH C18 was analysis column. The mobile phase were 0.10% formic acid and Methanol. The liner gradient elution was applicated. Electrospray ionization(ESI) source operating in negative and multiple reaction monitoring(MRM) mode were using mass-to-charge(m/z) transitions of precursor and product ions. The results showed good linear relationship with good precision and accuracy at the range of 100～1.00×104ng/mL for syringic acid, ellagic acid, quercetin and trans-cinnamic acid and 10.0～1.00×103ng/mL for others(r≥0.9900).The average recoveries for all analytes was between 77.6%～119%, The RSD was lower than 6.0%(n=6).(5) Analytical method of UPLC-MS/MS was developed to determinate free amino acids in concentrated fruit juices. The sample was derivatived completely by phenylisothiocyanate. BEH C18 was analysis column. The mobile phase was acetonitrile and 0.1% formic acid (contained 1mmol/L ammonium formate). The liner gradient elution was applicated. ESI source operating in negative and MRM mode were using mass-to-charge(m/z) transitions of precursor and product ions. The results showed good linear relationship with good precision and accuracy at the range of 50.0～1.00×103 ng/mL for aspartic acid and 10.0～1.00×103ng/mL for others(r≥0.9900).The average recoveries for all analytes were between 79.0%～119%. The RSD was lower than 8.1%(n=6). It was proved to be good reproducibility, rapid analysis speed and high sensitivity provided a new technology for analysis free amino acids in concentrated fruit juices.