采用GC/MS和HPLC-FLD2种方法测定黄酒中的EC含量

针对黄酒特性,采用固相萃取-气相色谱/质谱联用法(SPE-GC/MS)和高效液相色谱-荧光法(HPLC-FLD)分别测定黄酒中氨基甲酸乙酯(EC)含量,并进行了系统优化和比对。结果表明,SPE-GC/MS和HPLC-FLD法均能准确检测黄酒中的EC含量,测定结果可靠。其中,SPE-GC/MS法灵敏度较高,已被国际权威机构AOAC、OIV和欧盟纳入标准检测方法,宜选作我国黄酒EC含量检测方法标准。而HPLC-FLD法测定黄酒中EC更为简单快速,成本较低,易于掌握,适用于生产企业过程监控。     

Identification of Low Molecular Weight Peptides in Chinese Rice Wine (Huang Jiu) by UPLC‐ESI‐MS/MS

The aim of this work was to increase the general knowledge of peptide identification and to examine the low molecular weight peptides in Chinese rice wine (Huang Jiu) as there are very few publications in the literature on this topic. Chinese rice wine (Huang Jiu) has a high content of peptides and more than 500 peptides have been tentatively identified by ultra‐performance liquid chromatography‐quadrupole time‐of‐flight tandem mass spectrometry (UPLC‐ESI‐MS/MS), including 43 potential bio‐active peptides and 3 sensory‐active peptides, based on published references to date. These peptides have been tentatively identified according to the MS/MS spectra which produced sufficient information of product ions (complementary y ions and b ions). Results from this work indicated that it is feasible to produce rice wine with rich bioactive peptides and that there is potential to examine for rice wine authenticity and traceability based on the origin of the peptides.     

红茶中56种农药残留的GC-MS/MS定时SRM测定方法

建立了红茶中甲胺磷等56种农药残留的气相色谱-三重四级杆串联质谱(GC-MS/MS)测定方法。实验考察了不同提取剂的提取效果,比较了Cleanert TPT固相萃取柱和QuEChERS的净化效果,优选出以正己烷:丙酮=(7:3,V/V)提取,Cleanert TPT固相萃取柱净化的实验条件;采用优化的GC-MS/MS"定时SRM"模式进行测定,有效解决色谱保留时间出现偏移的问题。结果表明:与QuEChERS净化相比,经TPT柱净化后,54种农药信噪比提高了2倍以上;56种农药的检出限为1-18μg/kg。在3μg/kg-600μg/kg范围内,进行3个浓度水平的加标回收实验,除甲胺磷外,其余55种农药的平均回收率为73-126%,相对标准偏差(RSD,n=6)小于18%。本方法提取、净化效果良好,检测准确、灵敏、高效,适合红茶中56种农药残留的测定。     

Determination of antioxidant activity and phenolic compounds of Muntingia calabura Linn. peel by HPLC‐DAD and UPLC‐ESI‐MS/MS

Antioxidant activity in Muntingia calabura Linn. peel was evaluated by DPPH radical, ORAC, ABTS cation radical, FRAP assays and total phenolic contents by different extraction conditions. In addition, a method for determination of phenolic compounds in calabura peel samples harvested in Brazil using methanol:water and magnetic stirring as the extraction method, HPLC‐DAD and UPLC‐ESI‐MS/MS analysis were developed. Calabura peel showed antioxidant activity for all extraction conditions and assays evaluated, the most polar solvents being more effective. The developed HPLC‐DAD method allowed the accurate determination of phenolic compounds, with recoveries in the range of 72–107% and precision values ≤4%, with exception for chlorogenic acid. Gallic acid was determined at the highest concentration levels, followed by myricetin, ferulic acid and vanillic acid. However, all the five proposed phenolic compounds were identified in calabura peel samples by UPLC‐ESI‐MS/MS. Thus, calabura peel, an uncommon edible fruit part, can be appointed as a rich source of phenolic compounds.     

HPLC法测定黑米皮提取物中花色苷成分及含量

目的:用高效液相色谱法测定黑米皮提取物中花色苷的成分及含量。方法:采用HypersilBDSC18柱(250×4.6mm,5μm),以乙腈-4%磷酸:(15:85)为流动相,流速0.8ml/min,检测波长530nm,用外标法定量。结果与结论:黑米皮提取物中主要含两种花色苷:矢车菊定-3-葡萄糖苷和芍药定-3-葡萄糖苷,其含量分别为25.7%和1.7%。     

液相色谱-电喷雾串联质谱法测定饮用水中的萘二酚类物质

建立了饮用水中七种萘二酚的液相色谱-电喷雾串联质谱分析方法。样品用C18固相萃取柱富集,经滤膜过滤后进样,以甲醇-水为流动相,梯度洗脱,经C18柱分离后,采用多反应监测(MRM)负离子模式检测,外标法定量。空白样品及其添加实验结果表明,特征离子相对强度的比值稳定,无基质干扰,结合保留时间可实现准确的定性定量。在优化实验条件下,萘二酚类物质线性范围为0.50~50μg/L,线性关系良好,相关系数均大于0.998。方法检出限(以信噪比为3计)为1.0~3.0 ng/L,方法定量限(以信噪比为10计)为4.0~10 ng/L,井水、自来水、矿泉水样品添加水平为4.0~50 ng/L时,回收率为81.4%~112%,相对标准偏差(n=6)为2.1%~7.8%。该方法有前处理简单、回收率高、精密度好,灵敏度高,选择性强的优点,适用于饮用水中萘二酚类物质的测定。     

ICP-AES法测定黑糯米酒中的某些痕量元素

黑糯米酒固形物含量高而微量元素含量低.研究了ICP-AES测定该样品中微量元素时,采用微波炉消解和预灰化法等样品前处理技术.微波炉消解样品相对省时,但样品处理量小,试剂用量大,空白值高,测定结果误差较大,可靠性较差.预灰化法能有效解决微波消解存在的局限性,方法检出限(ng/g):砷3、铅2、铜0.05、锌0.2、镉0.02,RSD 0.83%～2.54%,加标回收率93.5%～108.2%.本法适用于固形物含量高的酒类产品中微量元素的测定.     

Determination of purine alkaloids and catechins in different parts of Camellia assamica var. kucha by HPLC‐DAD/ESI‐MS/MS

BACKGROUND: Kucha (Camellia assamica var. kucha) is a novel wild tea resource grown in China and a tea plant containing a sizable amount of theacrine (1,3,7,9‐tetramethyluric acid). High‐performance liquid chromatography (HPLC) analysis of purine alkaloids and catechins in young leaves of Kucha has been reported previously. However, the compositions of purine alkaloids and catechins in other parts of the plant remain unknown, and more information about the chemical constituents of Kucha is also necessary for further research and development of this new tea resource. RESULTS: Using HPLC with diode array detection coupled with electrospray ionisation tandem mass spectrometry (HPLC‐DAD/ESI‐MS/MS), three purine alkaloids, seven catechins and four non‐catechin phenolic compounds were identified or tentatively identified in Kucha. Purine alkaloids and catechins in leaves at different developmental stages, flowers, stems, pericarps and seeds of the plant were also quantified for the first time by the HPLC method, which was fully validated. Recoveries of the quantified compounds ranged from 96.67 to 104.33%. CONCLUSION: The results showed that the total contents of purine alkaloids and catechins were highest in young leaves of Kucha. Theacrine was detected in all parts of the plant and found to be most abundant in pericarps. Copyright © 2009 Society of Chemical Industry     

固相萃取-高效液相色谱法测定黄酒中氨基甲酸乙酯

建立一种反相高效液相色谱法测定黄酒中氨基甲酸乙酯的方法。样品经固相萃取柱净化后衍生,采用反相C18色谱柱XB—Cfsf4．6mm×250mm,5μm）,以乙腈-0．02moL／L乙酸纳水溶液为流动相进行梯度洗脱,流速为lmL／min;设定荧光检测器中激发波长为233nm,发射波长为600nm,对黄酒中的氨基甲酸乙酯进行检测。结果表明,在50．0-250．0μg／L添加量范围内,平均回收率为92．9％,相对标准偏差为4．5％（n=6）。方法的检出限为10μg／L,线性范围为100～1500μg／L（R=0．9995）,测定结果与标准气相色谱一质谱法基本相同。所建立的方法可以作为黄酒中氨基甲酸乙酯的检测方法。     

Citrinin Determination in Red Fermented Rice Products by Optimized Extraction Method Coupled to Liquid Chromatography Tandem Mass Spectrometry (LC‐MS/MS)

A rapid and sensitive method was developed and validated for citrinin determination in red fermented rice products by liquid chromatography tandem mass spectrometry (LC‐MS/MS) under the selected reaction monitoring mode. Sample preparation was especially focused, and the quantitative methods of LC‐MS/MS and high‐performance liquid chromatography with fluorescence detection (HPLC‐FLD) were compared. In red fermented rice samples, the limit of detection was 1.0 μg/kg for LC‐MS/MS compared to 250 μg/kg for HPLC‐FLD, the limit of quantification was 3.0 μg/kg for LC‐MS/MS compared to 825 μg/kg for HPLC‐FLD. High correlation coefficient was obtained (R² = 0.999) within the linear range (0.1 to 100 μg/L) in the MS method. The recoveries ranging from 80.9% to 106.5% were obtained in different spiking concentrations. The average intra‐ and inter‐day accuracy ranged from 75.4% to 103.1%, and the intra‐ and inter‐day precisions were from 3.3% to 7.9%. The developed method was applied to 12 commercial red fermented rice products, and citrinin was found in 10 samples ranging from 0.14 to 44.24 mg/kg. Compared to traditional qualitative and quantitative methods, the newly developed LC‐MS/MS method for citrinin determination includes the merits of using a small amount of extraction solvent, simple preparation steps, and high sensitivity.     

黑米黄酒工艺及产品稳定性研究

以黑米为原料生产黑米黄酒,黑米色素提取以浓度为20%-30％（v／v）的乙醇或米酒为最佳萃取溶剂,分两次萃取;黑米色素溶液及加工的黑米酒系列产品在酸性条件下色泽较稳定,适量使用蔗糖、柠檬酸或抗坏血酸等护色剂可明显提高产品色泽的稳定性;加工黑米黄酒,黑米原料仅需15％-20％,其余可用白糯米代替。（孙悟）     

Development and Application of a Method for the Analysis of 9 Mycotoxins in Maize by HPLC‐MS/MS

A reliable and sensitive liquid chromatography/tandem mass spectrometry (LC‐MS/MS) method was developed for the simultaneous determination of aflatoxins (AFB₁, AFB₂, AFG₁, and AFG₂), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEA), fumonisin B₁ (FB₁), and T2‐toxin in maize. The samples were first extracted using acetonitrile: water: acetic acid (79 : 20 : 1), and then further cleaned‐up using OASIS HLB cartridge. Optimum conditions for the extraction and chromatographic separation were investigated. The mean recoveries of mycotoxins in spiked maize ranged from 68.3% to 94.3%. Limits of detection and quantification ranged from 0.01 to 0.64 μg/kg and from 0.03 to 2.12 μg/kg, respectively. The LC‐MS/MS method has also been successfully applied to 60 maize samples, which were collected from Shaanxi Province of China. Twenty‐four of the total 60 samples (40%) were contaminated with at least 1 of these 9 mycotoxins. Occurrence of mycotoxins were 6.7%, 1.7%, 3.3%, 6.7%, 1.7%, 23.3%, and 3.3% for AFB₁, AFB₂, OTA, ZEA, DON, FB₁, and T2‐toxin, respectively. The results demonstrated that the procedure was suitable for the simultaneous determination of these mycotoxins in maize matrix.     

Determination of β‐Phenylethanol in Chinese Rice Wine by Reverse Phase High‐Performance Liquid Chromatography

The objective of this study was to develop a reverse phase HPLC method for determining the content of β‐phenylethanol in Chinese rice wine. The β‐phenylethanol was separated using a Synergi Hydro‐RP C18 (4.6 mm × 250 mm, 4 μm) column, CH₃OH:H₂O (50:50, v/v) as the mobile phase, and a diode array detector set at 210 nm. The results showed that when 5.00?30.00 mg/L of β‐phenylethanol was fortified, the average recoveries were between 99.5% and 99.8%, the RSD was 0.6% (n = 6), and the limit of determination was 0.05 mg/L. The calibration curve was linear over a range of 0.5 mg/L to 50 mg/L (R = 0.9999). The results of this method were almost the same as that of the gas chromatography method. The developed method is suitable to determine the β‐phenylethanol content in Chinese rice wine.     

气相色谱-质谱结合吸附萃取法测定陈酿黄酒挥发性香气物质

建立吸附法进行香气提取、气相色谱-质谱法测定不同酒龄黄酒中挥发性香气物质的方法。对比分析固相微萃取和搅拌棒吸附萃取对黄酒香气提取的效果,获得优化的香气提取方法。结果表明：采用搅拌棒吸附萃取-气相色谱-质谱法测定黄酒挥发性香气物质的平均相对标准偏差为11.47%,回收率为88.6%～92.3%,说明所建方法稳定;采用搅拌棒吸附萃取-气相色谱-质谱法共测得60种挥发性香气物质,其中15种醇类物质、25种酯类、6种醛类和5种酸类物质;随酒龄增加,乙醇含量逐渐减少,而11种酯类、1种醇类、1种酮类和1种醛类含量逐渐增加,随陈酿时间增加,部分醇、醛类物质被催化氧化成有机酸,酸的增加促进了酯化反应。搅拌棒吸附萃取-气相色谱-质谱法具有前处理简单快捷、重复性好等优点,可为黄酒香气分析提供准确可靠的数据。     

葡萄酒中17种残留农药的固相萃取-气相色谱/负化学离子源质谱测定方法研究

建立了葡萄酒中17种残留杀虫剂和杀菌剂的气相色谱～负化学离子源质谱（GC—NCI／MS）测定方法。采用C18。固相萃取小柱对葡萄酒中的残留农药进行富集,进一步完成萃取和净化,农药经乙酸乙酯洗脱后供GC—NCI／MS测定,采用基质匹配标准溶液外标法定量。验证实验表明,各农药在10-200μg／L浓度范围内线性关系良好,该方法定量检测限（S／N〉10）为5-20μg/L,在20μg,L和50μg／L处的加标回收率为70．1％-119．0％,相对标准偏差为3．5％-9．4％。该方法前处理简便快速,所采用的检测技术选择性和灵敏度高,适合葡萄酒中残留农药的测定．应用前景广阔。     

Optimisation of red pepper seed oil extraction using supercritical CO2 and analysis of the composition by reversed‐phase HPLC‐FLD‐MS/MS

Oil extractions from red pepper seed were performed by supercritical CO₂. Three‐level Box–Behnken factorial design (BBD) from response surface methodology (RSM) was applied to optimise the main extraction conditions including pressure, temperature and concentration of modifier (ethanol). The optimum conditions were as follows: extraction pressure, 27.17 MPa; extraction temperature, 47.67 °C; and the added concentration of modifier, 8.11 vol.%. Under the optimum conditions, the oil yield of 18.4% was obtained, which was well matched with the predicted yield. A simple, stable and sensitive method for the simultaneous determination of saturated and unsaturated free fatty acids in extracted oils using 2‐(11H‐benzo[a]carbazol‐11‐yl)‐ethyl‐4‐methylbenzenesulfonate (BCETS) as labelling reagent with fluorescence detection has been developed. All of free fatty acids (FFA) were found to give a linear response with correlation coefficients of >0.9991. The detection limits at a signal‐to‐noise ratio (S/N) of three are in the range of 19.06–41.19 fmol. This method should have powerful potential for the trace analysis of short‐ and long‐chain FFA from edible oils, foodstuff and other complex samples.     

高效液相色谱-电喷雾串联三重四级杆质谱法测定水中微囊藻毒素

目的研究利用固相提取净化、高效液相色谱-电喷雾串联三重四级杆质谱检测分析水中微囊藻毒素MC-LR和MC—RR。方法水样品经玻璃纤维滤纸过滤后,经C18固相提取柱富集净化,氮吹后定容。流动相中添加0．1％甲酸,采用梯度洗脱模式,经C18反相色谱柱分离,以电喷雾串联三重四级杆质谱定性、定量测定。结果线性定量范围0．1～5．0μg／kg,检测低限为MC-LR 0．01μg／kg,MC—RR 0．02μg／kg。结论此方法操作简便、定性定量能力较强,可作为检测水质量和评估食品安全风险的可靠方法。