Solid phase extraction oftrans-resveratrol from wines for HPLC analysis

Some recent studies have put forward the hypothesis that the presence oftrans-resveratrol (trans-3,5,4-trihydroxystilbene) in red wine may be related to some of its therapeutic properties. A fundamental step in view of this evaluation is the development of a method for the quick, accurate and precise analysis of this compound. Sample enrichment and purification can be obtained by solid-phase extraction using reverse-phase C₁₈ cartridges. HPLC analysis carried out by means of a photodiode-array detector, with an internal standard method, allows the detection of up to 10 g/L in wine, with a linear range between 0.6 and 300 ng injected and a precision of 3.3%. The results of the first analyses show that the concentrations oftrans-resveratrol in wines might be much higher than so far reported in the literature.

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HPLC-Analyse vontrans-Resveratrol in Wein nach Fest-Phasen-Anreicherung

Zusammenfassung Nach neueren Ergebnissen kann das Vorkommen vontrans-Resveratrol (trans-3,5,4-Trihydroxystilben) in Rotweinen eine therapeutische Bedeutung haben. Eine wichtige Voraussetzung ist deshalb eine möglichst schnelle und zuverlässige Bestimmungsmethode. Für die Anreicherung und Vortrennung dieser Komponente aus Wein wurde eine Fest-Phasen-Extraktion mit C₁₈-Umkehr-Kartuschen ausgearbeitet. Die anschließende HPLC-Analyse unter Anwendung der internen Standard-Auswertemethode und einem Dioden-Array-Detektor ermöglicht eine Bestimmung von 10 g/Ltrans-Resveratrol in Wein mit einer linearen Eichkurve von 0,6 bis 300 ng und einer Genauigkeit von 3,3%. Die Ergebnisse zeigen, daß die Resveratrol-Gehalte in Wein wesentlich (etwa zehnfach) höher sind als die bisher in der Literatur angegebenen Werte.

     

Solid phase extraction for the confirmation of results in polar pesticides residue analysis by HPTLC

HPTLC is a convenient method for confirming the presence and identification of pesticide residues following gas chromatographic analysis of sample solutions obtained by clean-up according to the Deutsche Forschungsgemeinschaft multiresidue method S 19. For several crops, however, the polar eluates 4 and 5 obtained from the small silica gel column are abounding with co-extractives which interfere with HPTLC determination and also with GLC in some cases. They are effectively removed by solid phase extraction on a small aminopropyl cartridge, using atertbutyl methyl ether/methanol (99+1) mixture as the eluant. The recoveries for 28 polar pesticides were not adversely affected.     

Solid phase extraction in the analysis of squalene and tocopherols in olive oil

Solid phase extraction (SPE) is only marginally employed in the official EU methods on the characteristics of olive oil. In the present study a SPE procedure was optimised for the subsequent extraction of squalene and α-tocopherol prior to HPLC of triacylglycerols. Squalene elution from a silica cartridge was achieved with 10 ml of n-hexane whereas α-tocopherol was isolated using 2 × 10 ml n-hexane/diethylether, 99:1, v/v. For both constituents, the precision of the SPE procedure (squalene: CV % = 4.4–6.4, n = 5; α-tocopherol: CV% = 5.3, n = 7) and the mean recovery (squalene: 88 ± 9% and 85 ± 4% for 700 and 4000 mg/kg levels of addition; α-tocopherol: 88 ± 6% and 91 ± 3% for 70 and 225 mg/kg levels of addition, respectively) were satisfactory with regards to those reported using other HPLC procedures with or without sample pretreatment. The results of the present study can be proved useful in the official control of virgin olive oil.     

Solid-phase extraction for HPLC analysis of dietary folates

Phenyl and cyclohexyl bonded silicas used for the solid-phase extraction (SPE) of dietary folates were studied and compared in terms of their retention capacities and recoveries. The SPE procedure was optimised to achieve the maximum recovery. The stabilities of folates in elution buffers and during the SPE procedure were also studied. The use of ascorbic acid throughout the SPE procedure was found to be important for the stabilisation of tetrahydrofolate – the most labile folate compound, whereas the use of both ascorbic acid and 2-mercaptoethanol was necessary to stabilise tetrahydrofolate during the storage of the eluates in the autosampler until analysis. Two purification methods, using phenyl endcapped (PH EC) cartridges or the combination of strong anion-exchange (SAX) and PH EC cartridges, were applied to the determination of folates in different food extracts, and verified by correlation with the usual purification method that uses SAX cartridges. The combination of SAX and PH EC cartridges was found to give the cleanest extracts.     

Solid phase extraction (SPE) method for detection of irradiated meats

Solid phase extraction (SPE) has been proposed as an alternative to the currently used florisil column chromatography. The hydrocarbons formed from beef, pork and chicken irradiated with 0-10 kGy were determined by the SPE and quantified by GC/MS. The limit of detection for the hydrocarbons in irradiated meats was 0.5 kGy. The correlation between the irradiation dose and the concentrations of hydrocarbons in beef, pork and chicken was high that linear regression coefficients (r²) were 0.87-0.99. SPE method would be used as the rapid detection of irradiated meats.     

Suitability of solid phase extraction and flame atomic absorption spectrometry for manganese partitioning in red wines

A suitability of a tandem column assemblage comprising a non-ionic adsorbing resin Amberlite XAD-16 and a strong cation exchange resin Dowex 50W-x8-200 linked in a series for the fractionation of Mn in wine was evaluated. Sorption and desorption properties of both sorbents towards simple ions of Mn(II) and its complex ions with citric and tannic acids were preliminary examined. The partitioning of Mn in wine was investigated using a solid phase extraction procedure developed and it resulted in classification of phenolic bound, cationic and residual fractions of Mn. It was found that in red bottled wines analysed Mn is predominantly present in the forms of cationic species, likely to be simple ions and complex ions with low molecular weight hydroxy acids. This fraction of a mean donation of 80% was assumed to be the most bioavailable.     

分散固相萃取-液相色谱法测定水果中氟吗啉残留量的不确定度

对分散固相萃取法-液相色谱法测定水果中氟吗啉残留量过程进行分析,建立数学模型。评定各不确定度分量,合成标准不确定度,计算测定结果的扩展不确定度。结果表明:主要来源于标准系列溶液配制,样品的均匀性和样品前处理过程的一致性,以及标准曲线的拟合。当置信概率为95%,采用该方法测定试样中氟吗啉残留的扩展不确定度为0.18,则试样中茚虫威残留的检测结果可表示为(1.46±0.18)mg/kg(k=2)。     

分子印迹聚合物在固相提取食物污染物质中的应用

无论是自然或人为的食品污染都会对人类的健康造成巨大的危害.连续照射食物产生的小剂量毒性化合物与多种癌症和严重的荷尔蒙异常有关,当今分析方法能够定量的检测污染物,但能应用在食物样品中的却少之又少.食物样品的预处理方法大部分基于快速廉价但选择性较差的固相提取技术,而免疫亲和性提取选择性好但价格昂贵,因此,廉价、快速、选择性好的分子印迹固相提取技术在食物污染物分析中起到了重要作用.本文将介绍分子印迹固相提取技术在检测杀虫剂、霉菌毒素和环境污染物等食物污染物中的应用.     

Reverse phase HPLC/DAD determination of biogenic amines as dansyl derivatives in experimental red wines

An accurate, rapid and very sensitive high-performance liquid chromatographic (HPLC) method for the determination of dansyl derivative of 11 biogenic amines, in experimental red wine samples from the crop year 2000 produced by Sicilian and French viticultures, was developed. The method involved the derivatisation with dansyl chloride followed by liquid chromatography gradient elution analysis without any other sample pre-treatment. The chromatographic system was equipped with a reversed-phase C-18 column and a DAD detector. A mobile phase of acetonitrile/water was used. The levels of biogenic amines in the samples ranged from 0.10 to 0.80 μg/ml. The HPLC method developed, showed a good linearity, sensitivity and repeatability. Recovery test ranged from 85.0% to 98.6% while detection limit was 0.01 ng/ml for all the studied compounds.     

固相萃取高效液相色谱法测定食醋中苯甲酸

建立了用固相萃取预分离,高效液相色谱法测定食醋中苯甲酸的新方法。食醋中苯甲酸用Strata-x33μmPolymericSorbent固相萃取小柱预分离,优化了萃取条件。以KromasilC18(5μm,250×4.6mm)为分离柱,10%甲醇/90%(0.02mol/mL)醋酸铵缓冲溶液为流动相,流速1.0mL/min,波长230nm,进行检测,方法回收率在93.5%～102.4%之间,日内、日间R.S.D.在1.2%～2.0%之间,最低检测浓度可达到6.9μg/L,具有良好的准确度和再现性。     

不同产区葡萄酒的对比检测分析

酚类化合物是一组具有大而复杂基团的化合物,它对红葡萄酒的特征和质量尤其重要.酚及其相关物质可影响葡萄酒的外观、滋味、口感、香气及微生物稳定性.本试验针对长城葡萄酒在不同产区生产的原酒进行检测分析,对比其因产地和加工工艺的不同而造成的葡萄酒中酚类物质含量的差异.     

Separation by solid phase extraction and quantification by reverse phase HPLC of sulforaphane in broccoli

The separation and quantification of sulforaphane [1-isothiocyanato-4-(methyl-sulfinyl)-butane] from the florets, stalks and leaves of broccoli is described. The procedure uses solvent extraction, followed by purification of extracts using solid phase extraction (SPE) and reverse phase HPLC analysis. The HPLC method is compared with a spectrophotometric assay. To obtain information about the usefulness of acid hydrolysis of glucosinolates, the florets were left to autolyze at room temperature or were treated with concentrated hydrochloric acid, then analysed. The method proves reliable and reproducible as regards both SPE purification and chromatographic determination. Quantities of sulforaphane were found in the florets, stalks and leaves. The highest content of sulforaphane (110 μgg⁻¹) was found in the leaves.     

Application of solid phase extraction techniques to analyse volatile compounds in wines and other enological products

Aroma compounds are most closely associated with the volatile fraction of foods. Common analytical separation procedures employed to analyse volatile compounds need, even today, that prior to GC analysis of an aroma or a fragrance, these compounds be concentrated or/and isolated from the non-volatile matrix. This step constitutes a problem that has still not been satisfactorily resolved and for this, several sample preparation methods can be found into the bibliography. This review gives a brief overview of solid phase extraction techniques to analyse volatiles. Procedures such as solid phase extraction (SPE), solid phase microextraction (SPME), stir bar sorptive extraction (SBSE), and the recent solid phase dynamic extraction (SPDE) will be discussed and critically evaluated. Contemporary applications of these techniques to the study of volatile compounds in wine and other enological products will be presented.     

固相微萃取-气质联用分析玉米煎饼的挥发性风味物质

本文以玉米煎饼为研究对象,采用顶空固相微萃取结合气相色谱-质谱,以4-甲基-2-戊醇为内标,分别对未发酵和自然发酵的玉米煎饼挥发性风味成分进行定性和定量分析,比较未发酵和自然发酵煎饼在风味上的差异。结果表明:未发酵玉米煎饼检测出15种挥发性物质,自然发酵玉米煎饼检测出22种挥发性物质,这些挥发性物质主要包括酮类、醛类、酯类、烯烃类、烷烃类和芳香类物质。经过发酵后玉米煎饼挥发性物质含量发生显著变化,醛类、酮类、烷烃类和芳香类化合物分别增加了1、2、4、2种,醛类化合物在所检出成分中占50%以上。      

The use of phenol compounds as parameters for distinguished red and rose wines from pale wines in multivariate analysis

The concentration of different types of phenol compounds and the ratio of such compounds to total phenols was established for red, rosé, and pale (claret) wines. Linear discriminant analysis was applied to these parameters to differentiate the red and rosé wines from the pale wines. Two discriminant functions correctly classified 100% of the red and rosé wines and 93.3% of the pale wines, with classification errors of 0.87% for the red wine-pale wine function and 1.7 × 10^–4% for the rose wine-pale wine function.

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Verwendung der Phenole bei der linearen Diskriminanzanalyse zur Trennung der Rot- und Roseweine yon Klaret-Wein

Zusammenfassung Man hat für Rot-, Rosé- und Klaret-Wein die Konzentration bestimmter Phenolanteile bestimmt und weiterhin ihr Verhältnis zu den gesamten Phenolen. Diese Parameter wurden mit der linearen Diskriminanzanalyse gemessen, mit dem Ziel, die Rot- und Roséweine von den KlaretWeinen zu unterscheiden. Zwei diskriminierende Funktionen reichen aus, um 100% der Rot- und Roséweine und 93,3% der Klaret-Weine zu klassifizieren, bei einer Fehlerquote yon 0,87% für Rot- zu Klaret-Wein und von 1,7 x 10^–4% für Rosé- zu Klaret-Wein.

     

分散固相萃取高效液相色谱法测定谷物中的桔霉素

目的:建立谷物中桔霉素含量的测定方法。方法:以60%乙醇作提取剂,C18吸附剂分散固相萃取净化样品中的桔霉素,应用高效液相色谱进行分析。结果:该方法标准曲线方程Y=3.13×10-7X-5.59×10-2,线性相关系数R2=0.9999,检出限为0.005mg/L,重复性实验精密度（RSD）为4.51%,加标回收率范围为87.7%⁹6.4%,所测的三种谷物样品桔霉素含量为0.116⁰.385μg/g。结论:该方法简便、准确,可用于谷物中桔霉素含量的测定。      

一种植物油中苯并（a）芘含量测定的固相萃取前处理方法

为了建立一种准确性高、成本低的植物油中苯并(a)芘测定的样品前处理方法,基于GB 5009.7—2016以自制氧化铝柱为固相萃取柱,采用单因素试验对称样量、洗脱剂量、洗脱流速、吸附剂存放时间、吸附剂量这5个影响植物油中苯并（a）芘洗脱的因素进行研究,优化前处理条件,并对测定方法进行考察。结果表明：优化的前处理条件为称样量0.100 0 g、洗脱剂量120 mL、吸附剂（氧化铝）量22 g、洗脱流速1滴/2 s、吸附剂存放时间少于12周;方法检出限为0.2 μg/L,样品加标回收率为94.23%～100.00%,RSD为1.20%～7.36%;同一样品测定结果与SGS测定值接近,相对平均偏差为2.36%～3.50%。说明本试验方法测定结果准确,可应用于油脂企业植物油中痕量苯并（a）芘的测定。     

Solid phase extraction as sample treatment for the determination of Ochratoxin A in foods: A review

Ochratoxin A (OTA) is a mycotoxin produced by two main types of fungi, Aspergillus and Penicillium species. OTA is a natural contaminant found in a large number of different matrices and is considered as a possible carcinogen for humans. Hence, low maximum permitted levels in foods have been established by competent authorities around the world, making essential the use of very sensitive analytical methods for OTA detection. Sample treatment is a crucial step of analytical methodology to get clean and concentrated extracts, and therefore low limits of quantification. Solid phase extraction (SPE) is a useful technique for rapid and selective sample preparation. This sample treatment enables the concentration and purification of analytes from the sample solution or extract by sorption on a solid sorbent. This review is focused on sample treatment procedures based on SPE prior to the determination of OTA in food matrices, published from 2010.     

活性炭固相萃取-高效液相色谱联用分析食品中的丙烯酰胺

实验建立了活性炭固相萃取-高效液相色谱联用分析食品中丙烯酰胺的方法,考察了方法的精密度、准确度和灵敏度,并用该方法获得了薯条的高效液相色谱图。结果表明,该方法的变异系数为3.439%,平均回收率为91.1%,灵敏度为0.05μg/mL。     

固相萃取-高效液相色谱测定奶粉中磺胺类抗生素残留

建立了测定奶粉中磺胺嘧啶和磺胺甲噁唑的固相萃取-高效液相色谱法。奶粉溶于水后经亚铁氰化钾和醋酸锌溶液处理后离心去除脂肪,过C18柱,用水淋洗,甲醇洗脱,洗脱液用于高效液相色谱分析。采用C18柱,流动相为甲醇∶0.08%乙酸=40∶60,检测波长272nm,流速0.8mL/min。结果表明,两种磺胺药物在0.05～1μg/mL的范围内线性良好,回收率为96.8%～97.5%。本方法具有灵敏度高,重复性好等特点。