超高效液相色谱-串联质谱法测定肉制品中的虾过敏原

目的：建立超高效液相色谱-串联质谱（ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS）法检测肉制品中虾过敏原的定量方法。方法：选取基质较为复杂的肉制品（西式火腿、香肠和肉丸）作为研究对象。样品经磷酸盐缓冲液（Phosphate buffer solution,PBS）超声提取30 min,离心（10000 r/min,15℃,10 min）后加入乙腈去除脂肪,取样液加入内标肽段（2.5μmol/L,40μL）和胰蛋白酶（1 mg/mL,10μL）在37℃下酶解16 h后上液质进行分析,样品经T3柱进行分离,0.1%甲酸-水溶液和乙腈梯度洗脱,多反应监测（multiple reaction monitoring,MRM）正离子模式采集数据,内标法定量。结果：采用该方法测定肉制品中虾过敏原蛋白含量,其中定量肽段在0.001～2.0μmol/L范围内,线性关系良好,决定系数R2为1.0000,检出限为0.67 mg/kg,定量限为2.00 mg/kg;在三个加标浓度水平下,回收率为83.2%...     

A rapid high-performance liquid chromatography with fluorescence detection method developed to analyze ochratoxin A in wine

A rapid, sensitive, reproducible, and inexpensive method of high-performance liquid chromatography with fluorescence detection (HPLC-FLD) for the analysis of ochratoxin A (OTA) in wine was developed. It is characterized by direct injection of the wine into the HPLC apparatus, with no need of extraction or cleanup. The method uses acetonitrile, water, and acetic acid (49:49:2, vol/vol/vol, respectively) as the isocratic mobile phase and a 5-microm monolithic C18 column (100 by 3 mm inside diameter). The relative standard deviation obtained in the OTA determination varied between 0.22 and 1.76%, with a mean value of 0.89%, in samples with concentrations between 0.10 and 100 ng/ml. The recovery of OTA ranged from 102% in samples spiked with 1 ng/ml OTA to 120% in samples with 0.10 ng/ml OTA. The method compared favorably with a published method based on an immunoaffinity column cleanup and a chromatographic assay with a C18 conventional HPLC column.     

Determination of Ascorbic Acid, Erythorbic Acid, and Uric Acid in Cured Meats by High Performance Liquid Chromatography

A paired-ion reversed-phase high-performance liquid chromatographic procedure with amperometric detection was applied to the determination of ascorbic acid (AA), erythorbic acid (EA), and uric acid (UA) in 5% meta-phosphoric acid extracts of beef bologna, beef frankfurters, bacon, and ham cured with AA or EA. AA concentrations (mg/ g meat) ranged from 0.008 in EA-cured beef frankfurters to 0.584 in AA-cured bacon. EA concentrations ranged from 0.149 in EA-cured beef frankfurters to 0.545 in EA-cured bacon. UA was quantified only in EA-cured bologna and frankfurters with 0.013 and 0.010 mg/g, respectively. Correlations of total ascorbate (AA + EA) by HPLC with fluorometric and calorimetric procedures were 0.992 and 0.988, respectively.     

香肠中红色2G的HPLC法及UPLC-MS/MS检测

建立香肠中红色2G色素的高效液相色谱法(HPLC)测定和确证的超高压液相色谱-质谱/质谱法(UPLC-MS/MS)。以0.662mol/L氨水为提取液,样品均质提取两次,离心后用C18柱净化,采用高效液相色谱-二极管阵列检测器(HPLC-DAD)检测,流动相为乙酸-乙酸铵缓冲液-甲醇(55:45,V/V),等度洗脱,流速为1mL/min,检测波长为530nm,阳性结果用UPLC-MS/MS确证。HPLC-DAD法在0.0212～1.06mg/L范围内,红色2G的峰面积与其相应浓度呈现良好相关性,r＞0.999,方法测定限为0.106mg/kg,在空白样品中添加已知浓度的红色2G色素,平均回收率在79.0%～86.5%之间,相对标准偏差(RSD)在3.19%～5.06%之间。UPLC-MS/MS法的测定限为0.005mg/kg,平均回收率在75.5%～80.2%之间,RSD在3.62%～9.97%之间。该方法可用于香肠中红色2G的检测及确证。     

Cholesterol oxidation in frozen dark chicken meat: influence of dietary fat source, and α-tocopherol and ascorbic acid supplementation

A factorial design assessed the effect of dietary fat source (beef tallow, fresh and oxidized sunflower oils, and linseed oil), and α-tocopheryl acetate (α-TA) and ascorbic acid (AA) supplementation (225 and 110 mg/kg feed, respectively) on the cholesterol oxidation product (COP) content and 2-thiobarbituric acid (TBA) values in raw and cooked dark chicken meat vacuum packaged and stored at -20°C for 7 months. COP determination showed good linearity, recovery and precision. Dietary α-TA was highly effective in protecting raw or cooked meat from cholesterol and fatty acid oxidation, regardless of its degree of unsaturation. In contrast, AA supplementation was ineffective and even promoted oxidation in raw meat from broilers fed unsaturated fat diets that had not been supplemented with α-TA. Oxidation values (raw or cooked meat) from α-TA or α-TA+AA supplemented diets were not statistically different (P>0.05). TBA and COP values were significantly correlated in raw samples (r=0.6466, P=0.0001).     

Fluorimetrische Bestimmung von Erythromycin-Rückständen in Lebensmitteln tierischer Herkunft nach Derivatisierung mit FMOC und HPLC-Trennung

A high-performance liquid Chromatographic (HPLC) method for the determination of the macrolide antibiotic erythromycin in eggs, milk, swine muscle, kidney and liver was developed. The drug was extracted from the matrix with acetonitrile. The raw extract was purified by liquid-liquid partitioning and fractionation by reversed-phase HPLC for additional cleanup. Erythromycin was reacted in a pre-column procedure with 9-fluorenylmethylchloroformate (FMOC) to enable fluorimetric detection (excitation 255 nm, emission 315 nm) after isocratic separation on an analytical RP-18 HPLC column. Mean recoveries ranged from 99% at fortification levels of 0.03 mg/kg in egg to 38% at 0.06 mg/kg in liver. With the exception of liver all detection limits were below 0.01 mg/kg and precision for all other matrices and tested concentrations (0.015–0.09 mg/kg) better than 20% (coefficient of variation).     

Folacin and Ascorbic Acid Retention in Fresh Raw, Microwave, and Conventionally Cooked Spinach

Fresh spinach was assayed for total folacin and reduced ascorbic acid content, before and after cooking by a microwave and conventional method. Mean ascorbic acid content of raw, microwave cooked and conventionally cooked spinach was 26.5 mg/lOOg, 13.5 mg/l00g, and 17.0 mg/lOOg, respectively. Ascorbic acid content was decreased significantly by both cooking methods; retention was 47% in microwave and 51% in conventionally cooked spinach. Total folacin content of raw, microwave, and conventionally cooked spinach was 161 mcg/lOOg, 183 mcg/lOOg, and 157 mcg/lOOg, respectively. Retention of folate was 77% in conventionally cooked and 101% in microwave cooked spinach.     

Improved clean-up for the determination of lasalocid in 'difficult' food matrices

Methodology has been developed for the determination of lasalocid in analytically 'difficult' matrices such as processed and spiced foods. The procedure was based on an existing silica-based solid-phase extraction (SPE) clean-up to which was added a novel NH 2 SPE step before HPLC with fluorescence detection. Use of the additional step enabled the determination of lasalocid in matrices such as baby food, meat pies ('pasties'), etc. Analysis of these matrices was not possible using the standard clean-up on its own. Chromatography showed a massive reduction in the amount of co-extractives and interferences. Validation data were obtained down to the 10-40 μg kg -1 level for a range of products. Recoveries ranged from 74% at 10 μg kg -1 for pork sausages to 96% at 40 μg kg -1 for meat pies.     

Nutrient retention in microwave cooked germinated legumes

The effects of germination on the cooking quality and nutrient retention in pressure and microwave-cooked Bengal gram, green gram and horse gram were studied. Ungerminated (UGL) and germinated legumes (GL) cooked in a microwave oven, and under pressure were analysed for moisture, protein, ash, iron, thiamin, ascorbic acid, in vitro protein digestibility (IVPD) and starch digestibility (IVSD) and bioavailable iron. Results revealed that microwave cooking required more water and time than did pressure cooking. The range of analysed constituents on dry weight basis in UGL and GL legumes, respectively, were as follows: protein, 18.2–23.5 and 19.4–25.7 g, ash, 2.1–2.9 and 2.2–2.9 g, iron, 5.4–7.3 and 7.3–10.3 mg, thiamin, 0.10–0.34 and 0.54–1.83 mg, ascorbic acid, 2.4–3.9 and 3.1–25.6 mg/100 g. The effect of germination and method of cooking on nutrient retention varied, depending on nutrient and severity of heat treatment. Microwave cooking caused 36–57% reduction of ascorbic acid while pressure cooking caused 10–30% loss. The IVSD in raw samples ranged from 18.4% to 22.1% in UGL and 33.6% to 43.6% in GL. Cooking of UGL and GL, by both methods, increased the starch digestibility threefold. The IVPD of raw UGL ranged from 64.6% to 66.2% and that of GL was 72.4–73.9%. In cooked UGL the IVPD ranged from 70.9% to 82.3% and, in GL, from 78.4% to 84.2%, showing a significant difference in cooking methods only in UGL. The iron bioavailability ranged from 11.5% to 18.7% in raw UGL while it was 18.3–20.6% in GL. GL had a higher content of thiamin and ascorbic acid, higher protein and starch digestibility and bioavailable iron, even after cooking.     

Direct determination of free tryptophan contents in soy sauces and its application as an index of soy sauce adulteration

A simple and rapid HPLC method using UV detector for determination of tryptophan (Trp) contents in pure fermented soy sauces, acid-HVP, and commercial soy sauces was developed. The method requires only simple sample pretreatment. The limit of detection (LOD) is estimated at 1 mg/L (signal-to-noise ratio of 3), and the recovery yields ranged from 92% to 108%. The analysis showed that Trp in all of the analysed acid-HVP samples was not detected and there was obvious detection of Trp (ranged from 136.4 to 261.8 mg/L) in all of the analysed fermented soy sauce samples. The observations suggest that Trp is a practical index of pure fermented soy sauce. The absence of Trp contents or lower level of Trp contents than that in pure fermented soy sauces suggests the soy sauces are not pure fermented soy sauces or presence of soy sauce adulteration. Simultaneous determination of levulinic acid (LV) in samples may be a good help in making assessment of soy sauce adulteration with acid-HVP.     

高效液相法测定市售腌制蔬菜商品中8种生物胺的含量

采用丹磺酰氯为衍生试剂,建立反相高效液相色谱法同时测定腌制蔬菜中色胺,β-苯乙胺,腐胺,尸胺,组胺,酪胺,亚精胺和精胺含量的方法。色谱条件:C18色谱柱分离,以水和乙腈为流动相梯度洗脱,流速0.8 mL/min,紫外检测器,检测波长:254 nm。在设定的试验条件下,8种生物胺在30 min内实现了良好的分离,待测生物胺峰面积同其相应浓度呈良好的线性相关性(R2>0.998)。仪器重复性良好(RSD<0.63%),方法重复性在可接收范围内(RSD<10%),8种生物胺的平均回收率在89.19%～103.02%之间。结果表明生物胺的HPLC检测方法,灵敏度高,精密度和重复性好,可快捷、准确地对腌制蔬菜中的生物胺进行检测。对市售腌制蔬菜样品中的生物胺含量进行了分析,检测出生物胺总量范围在39.38～628.82 mg/kg,属于目前我国安全标准范围之内。     

The determination of niacin in selected foods by capillary electrophoresis and high performance liquid chromatography: acid extraction

A robust method for the determination of niacin in raw and cooked meat and fish samples using acid extraction to liberate the niacin from the food matrix and capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) as the determinative steps is described. Niacin is liberated from the food matrix by autoclaving in the presence of 0.8 M sulphuric acid at 121°C for 2 h. C18 and cation exchange solid phase extraction (SPE) cartridges were used to isolate and concentrate the niacin before analysis. CE analyses were performed with an uncoated 50 μm extended light path fused silica capillary column and a buffer comprising of 7.5% acetonitrile and 92.5% of a 1:1 mixture of 0.02 M potassium dihydrogen orthophosphate and 0.02 M disodium hydrogen orthophosphate pH 7. Saccharin was used as the internal standard. The levels of niacin determined by CE compared favourably with those determined by HPLC (canned ham CE 3.5 mg/100 g, HPLC 3.3 mg/100 g; raw lamb CE 7.7 mg/100 g, HPLC 7.7 mg/100 g). The average recovery of niacin added to the samples prior to extraction was 103%. The limit of reporting for the determination is 0.5 mg/100 g. The procedure was suitable for only a limited number of other food types (e.g. fruit, vegetables and nuts). Alkali extraction of these foods using saturated calcium hydroxide followed by SPE cleanup and CE determination provided more reliable results. The limit of reporting for this procedure was 0.2 mg/100 g for fruit and 0.5 mg/100 g for vegetables.     

基于HPLC法同时测定牛心柿汁中5种有机酸含量

建立了高效液相色谱法（HPLC）同时测定牛心柿汁中5种有机酸含量的方法,并比较不同浓缩方式（真空、常压）柿汁中有机酸含量。结果表明,优化后的色谱条件为：紫外检测器检测波长210 nm,流动相为甲醇∶0.01 mol/L磷酸二氢钾溶液（pH2.7）=1∶99（V/V）,流速0.6 mL/min,柱温25 ℃。在此优化条件下,5种有机酸均能有效分离,线性范围较宽,相关系数R2＞0.999 0,检出限为3.03～26.39 μg/mL,定量限为10.0～87.95 μg/mL,加标回收率为90.13%～97.62%,精密度试验结果相对标准偏差（RSD）均＜5%,表明该检测方法精密度及准确度良好。HPLC结果表明,不同浓缩柿汁5种有机酸含量均低于原汁,真空浓缩优于常压浓缩,有机酸含量高且差异显著（P＜0.05）。有机酸含量变化分别为苹果酸0.129～0.151 mg/mL、奎尼酸0.152～0.209 mg/mL、乳酸0.030～0.068 mg/mL、乙酸0.239～0.533 mg/mL、柠檬酸0.297～0.326 mg/mL。     

高效液相色谱法测定乳酸菌发酵液中γ-氨基丁酸

通过对衍生试剂浓度、衍生时间、衍生温度、检测波长、流动相比例与柱温条件的选择,建立了一种高效液相色谱（HPLC）法灵敏检测发酵液中γ-氨基丁酸（GABA）含量的方法。以邻苯二甲醛为衍生化试剂,衍生时间5 min,衍生温度为室温,色谱条件为：检测波长228 nm,流动相为乙腈-20 mmol/L结晶乙酸钠溶液（21∶79,V/V）,柱温30℃,流速0.8 m L/min。结果表明,在γ-氨基丁酸含量0.05μg/m L～0.50 mg/m L范围内线性关系良好（相关系数R2=0.999 4）,平均加标回收率为91.87%～105.58%,精密度试验结果相对标准偏差（RSD）为0.55%～3.74%(n=5),检出限为0.02μg/m L。采用该方法检测发酵液中γ-氨基丁酸含量,其含量范围在0.157～0.369 mg/m L之间。该方法操作简单、灵敏、准确可靠,适用于发酵液中γ-氨基丁酸含量的检测。     

HPLC法同时测定采后莲雾果实7种有机酸的含量

为探讨采后莲雾果实有机酸代谢对果实絮状绵软和品质的影响,建立同时测定莲雾果实中7种有机酸含量的高效液相色谱法.采用Atlanis T3色谱柱(4.6 mm×250 mm,5μm)分离并进行梯度洗脱,流动相为甲醇和0.02 mol/L的磷酸盐(pH 2.2),流速0.5 mL/min,柱温25℃,紫外检测器,检测波长21...     

高效液相色谱法同时测定葡萄酒中9种人工合成色素

建立了葡萄酒中9种人工合成色素的高效液相色谱检测法。方法采用Zorbax SB-C18色谱柱分离,以25mmol/L乙酸铵水溶液-甲醇为流动相进行梯度洗脱。采用二极管阵列检测器,峰保留时间和峰扫描光谱纯度对照两种方式对样品峰进行定性,利用色素最大可见吸收波长测定各色素以消除杂质干扰。该方法的线性范围0.50mg/L~100mg/L,加标回收率95.8%~100.4%,相对标准偏差（RSD）为0.89%~1.26%。     

婴幼儿配方奶粉中酪蛋白磷酸肽2种检测方法的比较

目的比较婴幼儿配方奶粉中酪蛋白磷酸肽(casein phosphopeptides,CPPs)的2种主要检测方法。方法分别采用高效液相色谱法(high performance liquid chromatography,HPLC)和高效液相色谱-串联质谱法(high performance liquid chromatography-tandem mass spectrometry, HPLC-MS/MS)检测婴幼儿配方奶粉中酪蛋白磷酸肽的含量。结果 HPLC操作简便,检出限为7.5mg/100g,日内精密度≤2.7%,满足婴幼儿配方奶粉中酪蛋白磷酸肽的检测要求;而HPLC-MS/MS检出限为1mg/100 g,日内精密度≤8.8%,较HPLC具有更好的灵敏度。结论 HPLC高效准确,实验操作简单,适合于CPPs含量较高样品的检测分析;HPLC-MS/MS灵敏度高、特异性强,适用于CPPs含量较低样品的检测。     

高效液相色谱法测定腌渍蔬菜罐头中乙二胺四乙酸二钠的含量

建立高效液相色谱法测定腌渍蔬菜罐头中乙二胺四乙酸二钠含量的检测方法。试样中目标组分采用纯水提取,三氯化铁络合,PXA混合阴离子固相萃取柱净化,高效液相色谱检测,外标法定量。乙二胺四乙酸二钠的络合物质量浓度在1.0～100.0 μg/mL范围内时,线性关系良好,其相关系数为0.999 95,检出限为0.09 mg/kg,定量限为0.31 mg/kg,添加量在0.03～0.3 g/kg范围内,平均加标回收率为99.09%～103.95%,相对标准偏差为0.4%～3.3%。该方法准确度高、重复性好,适合腌渍蔬菜罐头中乙二胺四乙酸二钠含量的检测。     

流动注射法同时检测水中挥发酚和氰化物

目的建立连续流动注射分析仪同时测定末梢水中挥发酚和氰化物的分析方法。方法末梢水经过EDTA和抗坏血酸的混合溶液(20.0 g/L)预处理,用连续流动注射分析仪同时测定挥发酚和氰化物。结果末梢水样品预处理的条件为50 ml水样中加入0.5 ml EDTA和抗坏血酸的混合溶液(20.0 g/L),加标回收率为90.0%~105.0%,相对标准偏差为0.39%~5.85%,挥发酚和氰化物的检出限分别为0.000 2和0.000 4 mg/L。结论该方法精密度好,准确度高,符合分析质控要求。     

Control of nutritional labels in beverages with added vitamins: screening of β-carotene and ascorbic acid contents

Simple, rapid and inexpensive methods were used for the determination of β-carotene and ascorbic acid, while checking recovery and precision with samples, and calibration data and detection levels with standards. These methods involved direct injection of the beverage into an HPLC with an UV-Visible detector. The results obtained with 13 beverages, with different β-carotene and ascorbic acid levels added, did not show good agreement between the vitamin levels on the labels and the levels determined. Found levels, in virtually all drinks, were much higher than those stated on the nutritional label.