Bioactives Screening in Overripe Fruits and Vegetables by Liquid Chromatography Coupled to Photodiode Array and Mass Spectrometry Detection

Food waste production generated by large distribution represents an emerging issue due to the large polluting impact and, at the same time, due to the enormous increase of nutrients’ need worldwide. Overripe fruits are considered as “food wastes” despite they could be yet rich sources of food ingredients and bioactives, such as carotenoids and polyphenols. In this work, a phytochemical screening of 20 selected overripe vegetables and fruits was accomplished by liquid chromatography coupled to photodiode array and mass spectrometry detection. The obtained results showed that the low-sugar-content fruits and vegetables had a higher bioactive content compared to the high-sugar fruits; in particular, tomato, wild swiss chard, green bell pepper, and lettuce leaves were the richest in bioactive phytochemicals. Green bell peppers showed the highest pigment content (875.3 mg/kg), whereas tomato, wild swiss chard, and lettuce leaves showed the highest polyphenol contents, 4541.9, 1692.4, and 712.9 mg/kg, respectively. This is the first work where a large-scale monitoring of bioactives in overripe fruits was carried out and two mixtures of fresh and dry material for animal feed are presented.     

高效液相色谱法定量分析固态发酵食醋中有机酸的方法优化

优化固态发酵食醋中9 种有机酸的高效液相色谱定量分析方法。色谱条件：以C18色谱柱进行分离,流动相为NaH2PO4溶液,流速为0.9 mL/min,检测波长为210 nm,可在14 min内完成检测。在优化的色谱条件下,9 种有机酸的检测线性范围较宽,最低检出限为0.02～1.79 mg/L,加标回收率为96.02%～104.55%,相对标准偏差0.46%～3.52%。该方法具有灵敏、准确、稳定等优点,可用于固态发酵食醋中有机酸的测定。     

燕窝中唾液酸的DAD/FLD串联HPLC测定方法研究

建立燕窝中唾液酸的柱前衍生二极管阵列/ 荧光检测器(DAD/FLD)串联的反相高效液相色谱检测方法。用硫酸氢钠溶液水解样品,以邻苯二氨盐酸盐为衍生化试剂,采用C18 柱分离,四氢呋喃溶液(含体积分数0.5%磷酸和体积分数0.15% 正丁胺)- 乙腈为流动相等度洗脱,流速1.0mL/min,二极管阵列检测波长230nm,荧光激发波长(Ex) 230nm,发射波长(Em) 425nm。结果表明,唾液酸在0.1～750μg/mL 范围内线性良好(r ＞ 0.9990),20min内完全分离,回收率在85.03%～97.14% 之间。检出限0.2μg/mL(DAD),0.005μg/mL (FLD),FLD 检出限比DAD低两个数量级且杂峰少,在DAD 检出限以上的相同浓度下,DAD 比FLD 更灵敏。本方法具有灵敏度高,重复性好,分析速度快等特点,可准确测定燕窝等样品中唾液酸含量。     

基于高效液相色谱法分析梨酒发酵前后有机酸变化

砀山梨、库尔勒香梨和库尔勒香梨芽变梨去皮榨汁后接入酵母发酵酿制,采用高效液相色谱（high performance liquid chromatography,HPLC）法对其发酵前后有机酸成分及含量进行分析。优化后色谱条件：色谱柱为CNWC18 柱（250 mm×4.6 mm,5 μm）;紫外检测波长为210 nm;流动相为0.01 mol/L 磷酸氢二铵（pH2.45）;流速为1.0 mL/min。与梨果汁相比,梨酒中有机酸总量增加,库尔勒香梨芽变梨酒中最高,为10.543 mg/mL。3 种梨酒中酒石酸、莽草酸、柠檬酸、琥珀酸和乳酸含量增加,草酸含量降低;砀山梨酒中苹果酸含量下降,库尔勒香梨和库尔勒香梨芽变梨酒中含量增加。3 种梨酒中,酒石酸含量由高到低为库尔勒香梨芽变梨酒＞库尔勒香梨酒＞砀山梨酒,库尔勒香梨芽变梨酒中乳酸含量为1.568 mg/mL,砀山梨酒乳酸含量为1.183 mg/mL,库尔勒香梨酒乳酸含量为0.861 mg/mL。砀山梨酒的琥珀酸含量为1.996 mg/mL,其含量高于库尔勒香梨和库尔勒香梨芽变梨酒。库尔勒香梨酒中柠檬酸含量（0.544 mg/mL）显著高于其他2 种梨酒。不同发酵温度下梨酒中各有机酸含量差异明显,15 ℃下发酵的砀山梨和库尔勒香梨酒中有机酸总含量略低于25 ℃,在15 ℃发酵温度下,库尔勒香梨酒中苹果酸和库尔勒香梨芽变梨酒琥珀酸含量高于25 ℃。发酵后梨酒中酒石酸、乳酸和琥珀酸为主要有机酸,且3 种梨酒中有机酸含量存在较大差异。     

UPLC快速测定葡萄酒中酚类物质的方法

建立一种新型、快速测定葡萄酒中多种单体酚的超高效液色谱方法。采用Waters BEH C18色谱柱（2.1 mm×50 mm,1.7 μm）;色谱条件：流动相A为1%乙酸溶液,流动相B为乙腈;流速为0.2 mL/min;检测波长为210～400 nm;梯度洗脱15 min。方法精密度（n=6）实验的17 种酚类物质的平均相对标准偏差为0.25%～0.66%,对葡萄酒进行加标回收率实验的17 种酚类物质回收率范围为85.10%～102.33%。该方法简单省时、精确可靠、重复性好,非常适用于葡萄酒中酚类物质的定性与定量分析。     

Optimized Formation,Extraction, and Determination of Sulforaphane in Broccoli by Liquid Chromatography with Diode Array Detection

A new method has been developed to determine sulforaphane in broccoli florets, stems, and leaves using liquid chromatography coupled to diode array detection. The hydrolysis reaction, required to convert glucoraphanin to its breakdown product, sulforaphane, and the extraction procedure, based on solvent extraction with methyl t-butyl ether followed by solid phase extraction with silica cartridges, were optimized for the three broccoli matrices; the resulting recovery values ranged from 92 to 102 % in all cases. A fast separation was performed on a C₁₈ analytical column with a mobile phase composed of ammonium formate (20 mM) in water and acetonitrile (55:45, v/v) in isocratic elution mode. This method was fully validated and was found to be selective, linear from 2.5 to 800 mg/kg, and precise (percent relative standard deviation values below 5 %). Moreover, the limits of detection and quantification were 0.8 and 2.5 mg/kg, respectively. Finally, the proposed method has been applied to the analysis of sulforaphane in broccoli samples of two different cultivars (Parthenon and Marathon).     

高效液相色谱法测定发酵辣椒中的有机酸

建立了高效液相色谱法同时分析发酵辣椒中8种有机酸的方法.采用Hypersil-ODS2色谱柱(4.6mm×200mm,5μm),色谱条件为:2%甲醇-0.05mol/L KH2PO4(pH2.8)作为流动相,流速0.8ml/min,柱温17℃,进样量5μl,检测波长214nm.在此条件下,8种有机酸能够得到较好的分离,回收率92.87%～106.15%,RSD＜3%.同时还比较了不同提取方法的提取效果,表明加热提取比超声波提取的效果更好.     

Determinations of Organic Acids in Potatoes by High Performance Liquid Chromatography

A high performance liquid chromatographic method has been developed to quantify the major organic acids in potatoes oxalic, citric, malic, fumaric and ascorbic acids. Tubers were extracted with 95% ethanol:water:concentrated sulfuric acid 60:40:0.2 followed by injection on an Aminex HPX-87 column with a mobile phase of 0.018N sulfuric acid. Ascorbic acid was detected at 260 nm while the other four acids were quantified at 210 nm unless fructose was present at a concentration of 6 mg/g or higher, in which case 220 or 230 nm was used. Greater than 90% recovery was observed for all acids with most recoveries near 100%. The method has been shown to be very reproducible with the CV% ranging from 1.3-12.3 while the majority were below 4%. Analyses of several potato varieties have shown a wide variation in acid content among varieties.     

转基因大米中氨基酸含量的超高效液相色谱定量

建立了一种6-氨基喹啉基--羟基琥珀酰亚氨基甲酸酯(AQC)柱前衍生,超高效液相色谱(UPLC)对大米中17种氨基酸进行快速定量的方法。优化了6 M盐酸和0.2%苯酚的加入量、水解时间等大米水解条件,采用1.7μm粒径的AccQ·Tag ULTRA C18色谱柱分离,260 nm检测,可在9.5 min内实现17种氨基酸衍生物的分离。结果表明,17种氨基酸的标准工作曲线的线性回归相关系数(r)均大于0.999,加标回收率在85.9%~102%之间,日内相对标准偏差(RSD)(n=5)2.64%~4.59%,日间相对标准偏差(n=3)1.43%~5.06%,方法简单、准确、快速、重复性和再现性良好。将该方法用于大米中氨基酸含量的分析,比较了4对转基因大米及其非转亲本之间氨基酸含量的差异,T检验结果表明,所取样分析的转基因大米及其亲本之间在氨基酸含量上没有显著性差异。     

正相超高压液相色谱法测定植物油中的维生素E

采用正相超高压液相色谱法测定油脂中4种常见生育酚的含量,确定一种简单、准确、快速测定维生素E的测定方法.样品经前处理后,用Zorbax RX-SIL硅胶柱分离,以乙酸乙酯-异辛烷为流动相梯度洗脱,在波长295nm采用外标法检测α、β、γ、δ等四种生育酚在不同植物油中的含量.研究结果表明,该方法四种异构体均在8min内出峰,线性关系在0.9994～0.9999间,精密度RSD＜5％,加标回收率在80％～100％,线性范围0.2～100.0μg/mL,α、β、γ、δ异构体方法检出限均在0.01μg/g左右;几种典型植物油样品验证实验表明该方法体系具有快速、准确、分离度好等特点.同时比较了调和油和精炼地沟油维生素E含量差异,初步确定α-维生素E可能作为该类地沟油识别因子.     

高效液相色谱法测定酸汤中的有机酸

建立了高效液相色谱法快速测定酸汤中五种有机酸的方法,在C18反相色谱柱,紫外检测器(波长210nm),0.01mol/L磷酸二氢铵缓冲溶液(pH 2.6)∶甲醇为95∶5作为流动相洗脱,流速为1.0mL/min,柱温为25℃的色谱条件下,同时分析酸汤中5种有机酸,有机酸标准曲线相关系数均在0.9970～0.9985之间,回收率在90.5%～97.6%之间,方法检出限0.1～0.3μg/mL,相对标准偏差为0.7%～3.1%。该方法具有操作简单、重复性好、准确度高的特点。     

高效液相色谱法测定葡萄酒中的有机酸

对长城和王朝葡萄酿酒公司的15种原酒进行了10000转／min高速离心预处理后，利用高效液相色谱法(HPLC)测定其中有机酸。结果表明：葡萄酒中主要有机酸成分是酒石酸、L-苹果酸和L-乳酸，柠檬酸、琥珀酸和乙酸的含量很少；干白酒中几乎不合有L-乳酸；干红酒中含有L-乳酸，但L-苹果酸和柠檬酸含量相应减少，甚至为0；在所测酒样中，长城原酒中的总酸含量比王朝原酒中的高，主要是酒石酸的含量高。     

Determination of Organic Acids in Dairy Products by High Performance Liquid Chromatography

A high performance liquid chromatographic method was developed for the quantitative analysis of organic acids in dairy products. A reverse-phase C8 column at room temperature, a mobile phase of 0.5% w/v buffer ((NH₄)₂HPO₄ at pH 2.24 with H₃, PO₄)-0.4% v/v acetonitrile, UV detection at 214 nm and 1.2 mL/min flow rate were utilized. Formic, acetic, pyruvic, propionic, uric, orotic, citric, lactic and butyric acids were quantitated for raw milk, yogurt, Blue, Provolone, Port Salut and Quartirolo cheeses. Recoveries greater than 85.3% were observed for all acids.     

Determination of Arsenic Species in Edible Mushrooms by High-Performance Liquid Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometry

The content of total arsenic was determined by inductively coupled plasma mass spectrometry after microwave digestion. The results showed that the content of total arsenic was ranged from 0.04 to 212.3 mg kg^?1 in the test edible mushrooms. The content of total arsenic in eight test samples was greater than 0.5 mg kg^?1. However, the toxicity of arsenic is closely related to the chemical form. Therefore, the determination of arsenobetaine, arsenocholine, dimethylarsinic acid, monomethylarsonic acid, arsenite, and arsenate in edible mushrooms was performed on an ion exchange chromatography column (Dionex IonPac AS19) with inductively coupled plasma mass spectrometry as a detector. When water and 50 mM (NH₄)₂CO₃ (pH = 9.7) were worked as a mobile phase, the six arsenic species could be well separated in 20 min. Ultrapure water was selected as extraction solvent for the validation of ultrasound-assisted extraction method due to its advantage of simple, cheap, and high extraction efficiency. Under optimum conditions, the limits of detection were <2.5 μg kg^?1 of the test arsenic species for arsenic, and the recoveries of all six arsenic species were >91.0 % with the relative standard deviation of <5.5 %. The method was applied to 19 different mushroom samples. The results indicated that the total content of arsenic species was basically identical with the content of total arsenic. And arsenobetaine was proved to be the main arsenic species in the test Lentinus edodes-2 sample.     

超高效液相色谱快速测定卷烟主流烟气中7种挥发酚

为快速准确地测定卷烟烟气中的对-苯二酚、邻-苯二酚、间-苯二酚、苯酚、对-甲酚、邻-甲酚和间-甲酚,建立了同时测定卷烟主流烟气中7种挥发酚的超高效液相色谱( UPLC)方法.采用1％醋酸水溶液对捕集烟气粒相物的剑桥滤片超声萃取20 min,萃取液过滤后通过Acquity UPLC BEH C18色谱柱分离,以水相中含7.0×10-3 mol/Lβ-环糊精(β-CD)的流动相进行梯度洗脱,采用荧光检测器进行分析.该方法的相对标准偏差( RSD)为1.15％～5.79％,回收率为90％～102％,检测限为0.04 ～ 0.35 μg/支,分析时间9 min.该法适合批量卷烟主流烟气中7种挥发酚的快速分析.