高效液相色谱法测定啤酒、发酵液和麦汁中的糖类和乙醇

Cheethan和Rajkyla提出以十八烷基修饰的硅胶作为固定相,以纯水作洗脱液,来分离单糖和寡糖,类似方法应用于啤酒工业分析的国内报道,仅见一篇文章,国外文献报道、美国酿造化学家协会(ASBC)和欧洲酿造协会(EBC)推荐的高效液相色谱法(HPLC),多采用阳离子交换柱分析酿造用辅料,麦汁,发酵液,啤酒中的糖类.目前国内大啤酒厂多采用啤酒分析仪测定乙醇,很少采用气相色谱法(GC)和液相色谱法(HPLC).采用GC直接测定乙醇含量,由于啤酒中乙醇含量远高于其它杂醇油,GC法测定杂醇油时,难以定量测定乙醇,除非采用填充柱,单独测定乙醇.本文方法采用Nucleosil C18柱,测定啤酒,发酵液和麦汁中的糖类时,同时测定乙醇.     

高效液相色谱法测定输液袋中12种抗氧剂的迁移量

建立了基于高效液相色谱法(HPLC)测定输液袋中12种抗氧剂迁移量的分析方法。样品经盐析辅助液液萃取后,过0.22μm有机系滤膜,以甲醇-0.1%磷酸为流动相,经Shim-pack GIST-HP C18色谱柱(150 mm×2.1 mm,3μm)分离,二极管阵列检测器测定,外标法定量。分别优化了梯度洗脱程序、柱温和进样量。在优化后的色谱条件下,12种目标化合物在26 min内实现有效分离,且线性关系良好,平均加标回收率为84.3%～108.7%,相对标准偏差(RSDs)为0.1%～3.1%,检出限(LODs)为0.2～0.4 mg/L。本方法可用于输液袋中12种抗氧剂迁移量的检测。     

快速柱前衍生HPLC法检测曲格列汀中(R)-3-氨基哌啶

以邻苯二甲醛(OPA)和3-巯基丙酸为衍生试剂,建立了柱前衍生高效液相色谱(HPLC)测定曲格列汀中(R)-3-氨基哌啶含量的分析方法.(R)-3-氨基哌啶与衍生剂在碱性(pH 10.5)条件下于室温反应30s,进行柱前衍生,并利用高效液相色谱-质谱对衍生产物进行定性分析.采用YMC-Triart C18色谱柱(150...     

超高效液相色谱-串联质谱法测定纸制食品接触材料中丙烯酰胺的迁移量

为评估纸制食品接触材料中丙烯酰胺迁移的合规性和风险性,该文采用超高效液相色谱－串联质谱建立了测定纸制食品接触材料中丙烯酰胺迁移量的方法。采用Agilent Poroshell 120 SB－Aq（4.6 mm × 100 mm,2.7 μm）为分离柱,以0.1%（体积分数）甲酸水溶液和甲醇（9∶1）为流动相进行等度洗脱,质谱分析采用电喷雾离子源（ESI）,多反应监测（MRM）正离子模式。结果表明,丙烯酰胺在不同食品模拟物中的含量与其色谱峰面积呈线性关系。其中水溶性食品模拟物的线性范围为5.0～100.0 μg/L,检出限为1.0 μg/L;油性食品模拟物的线性范围为10.0～200.0 μg/kg,检出限为5.0 μg/kg。空白样品的平均加标回收率为90.0%～113%,相对标准偏差（RSD,n = 6）为0.40%～4.6%。3种类型纸制食品接触材料样品的测试结果显示,纸吸管中丙烯酰胺迁移量的阳性检出率较高,存在食品安全风险隐患。     

压敏胶贴片中芍药苷及残留溶剂含量的测定

建立了贴片中标示成分芍药苷含量的高效液相色谱(HPLC)法和贴片中各种残留溶剂含量的气相色谱(GC)法。样品经甲醇提取,离心分离后,以乙腈-水(含4%HAc)的体积比为16∶84作流动相,选择ODS-2HypersilC18(150×4.6mm,5μm)色谱柱,测定芍药苷含量。贴片基质经乙醚处理,离心分离,以GC内标法测定残留溶剂含量。结果表明:HPLC法的精密度、重现性和回收率良好;GC法测得乙酸乙酯、异丙醇、乙醇三种残留溶剂,贴片中残留溶剂总量为2.1×10-4,符合药典限度规定。     

高效液相色谱测定水稻幼苗中内源激素(GA_3、IAA和ABA)的方法研究

本文着重研究了应用高效液相色谱法(简称为HPLC)测定水稻中内源激素GA_3、IAA和ABA;并提出了植物激素经有机溶剂提取分离后,不经DEAE纤维柱洗脱,而用0.5μm超滤膜过滤纯化,就可用高效液相色谱分析测定。该法简便、快速(过滤只需1～2分钟),用样量少。可靠性较好,尤其在定性分析方面,显示了它的优点。     

薄层色谱法鉴别槐枝及高效液相色谱法测定其中芦丁含量

建立槐枝的薄层色谱(TLC)鉴别及高效液相色谱(HPLC)法测定其中芦丁含量的方法。样品中加入石油醚(30~60℃)脱色,然后用甲醇超声提取,以乙酸乙酯-甲醇-甲酸-水(体积比为8∶1∶1∶1)为展开剂,建立槐枝的薄层色谱鉴别方法。选用Kromasil C18柱(250 mm×4.6 mm,5μm)为分离柱,流动相为甲醇-1%冰醋酸溶液(体积比为32∶68),流量为1.0 mL/min,柱温为36℃,采用HPLC法测定芦丁含量,检测波长为257 nm。芦丁的质量在45.3~226.5 ng范围内与色谱峰面积具有良好的线性关系,相关系数为1.000,方法检出限为1.54 ng。测定结果的相对标准偏差为1.6%(n=6),样品加标回收率为98.7%~102.2%。所建立的薄层色谱鉴别方法及高效液相色谱法测定其中芦丁含量的方法可以有效控制槐枝的质量。     

气相色谱法和高效液相色谱法测定角膜塑形镜中3种单体的残留量北大核心CSCD

提出了气相色谱法(GC)和高效液相色谱法(HPLC)测定角膜塑形镜中甲基丙烯酸(MAA)、3-(异丁烯酰氧)丙基三(三甲基硅氧烷)硅烷(TRIS)、1,1,1,3,3,3-六氟异丙基异丁烯酸酯(HFIPM)等3种单体残留量的方法,并对两种方法的方法学验证与样品测定结果进行比较。取不少于200 mg的镜片样品,置于真空干燥箱中,于(60±5)℃真空条件下干燥不少于24 h至恒重。将恒重后的样品放入索氏提取器中,加入100 mL二氯甲烷,加热提取4~6 h。提取液转移至100 mL容量瓶中,用二氯甲烷定容,得到供试品溶液。GC采用DB-WAX毛细管色谱柱(30 m×0.32 mm,0.5μm),以氮气为载气,以柱升温程序方式分离,以氢火焰离子化检测器检测。HPLC采用CAPCELL PAK C_(18) MGⅡ色谱柱(150 mm×4.6 mm,5μm),以不同体积比的0.1%(体积分数)磷酸溶液和乙腈的混合溶液为流动相,以梯度洗脱方式分离,以二极管阵列检测器检测。结果显示:GC得到的标准曲线的线性范围为1.0~1 000 mg·L^(-1),检出限为0.006%~0.010%;HPLC得到的标准曲线的线性范围为0.1~200 mg·L^(-1)(MAA、HFIPM)和1.0~1 000 mg·L^(-1)(TRIS),检出限为0.001%~0.009%,表明GC适用于测定高残留量样品,HPLC适用于测定低残留量样品。GC所得回收率为89.1%~111%,测定值的相对标准偏差(RSD,n=6)为0.83%~4.1%;HPLC所得回收率为90.5%~108%,测定值的RSD(n=6)为0.92%~4.7%。在显著性水平为0.05条件下,经F检验和t检验分析,两种方法的测定结果无显著性差异。对3批来自不同生产企业的角膜塑形镜进行残留量和迁移量试验,结果显示:3批样品中均检出TRIS残留,TRIS的迁移量最大值为0.112%;2批样品中检出MAA残留,1批样品中检出HFIPM残留,而MAA和HFIPM均未在迁移量试验中检出。     

柱前衍生化高效液相色谱法测定细胞培养液中的前列腺素E2

前列腺素（PGs）参与体内多种病理生理过程,其含量的微小变化会产生很大的生理效应差异,因此准确测定生物样本中PGs的含量具有重要意义。高效液相色谱-荧光检测法（HPLC—FD）逐渐用于检测PGE2等PGs。目前国内尚无HPLC—FD法测定生物样本中PGs含量的报道。本实验采用以4-溴甲基-7-甲氧基-香豆素（BrMMC）为衍生试剂,碳酸钾、双环己基-18-冠醚-6为催化剂的柱前衍生化HPLC—FD法成功地分离并测定了细胞培养液中的PGE2。     

柱前衍生高效液相色谱法测定鱼罐头中的组胺

建立了一种测定鱼罐头中组胺含量的柱前衍生高效液相色谱(HPLC)方法。样品匀浆后采用高氯酸水溶液超声提取,提取液经丹酰氯衍生后,采用HPLC分离,紫外检测器检测,外标法定量。采用粒径为1.8 μm固定相填料的C18色谱柱,在0.3 mL/min的流速下,样品的分析时间小于5 min,并可有效地减少流动相消耗,节约成本。组胺在0.08～8.00 mg/L内线性关系良好,相关系数为0.99998;酱煮鲐鱼罐头中组胺在不同浓度水平的平均加标回收率均大于96%,相对标准偏差(RSD)小于2.5%;鱼罐头中组胺的定量限可达5.00 mg/kg。所建立的HPLC方法快速、灵敏度高、重复性好,前处理方法简单,可用于鱼罐头中组胺的测定。     

医用聚丙烯酰胺水凝胶理化性能测试

测试了医用聚丙烯酰胺水凝胶产品的pH值、折射率、重金属含量、红外光谱、化学热稳定性和丙烯酰胺单体残留量等主要理化性能，重点研究了样品中残留单体丙烯酰胺的高效液相色谱分析法。     

SPE/HPLC/UV studies on acrylamide in deep-fried flour-based indigenous Chinese foods

A fast and cost-effective method using HPLC/UV has been developed for determination of acrylamide in deep-fried flour-based leaven dough foods available in Hong Kong. The samples were purified by a simple solid-phase extraction method which combined Oasis HLB and Bond Elut-Accucat cartridges. The aqueous sample solution was centrifuged at 14,500 ×g and 0 °C for 15 min to successfully remove the fat in the samples. A gradient elution program and a mobile phase of 4.0% v/v acetonitrile in water allowed sufficient retention and well resolved acrylamide from the food matrices in the sample extracts. Acrylamide was detected at UV wavelengths of 210 and 225 nm. The amounts of acrylamide in eight food samples were 27-198 μg/kg when 1-g samples were analyzed. The recoveries of acrylamide were larger than 78.0% and the precisions were 2.1-10.9% (n = 3). Our proposed method is especially relevant for analyzing acrylamide in those oily food matrices.     

固相萃取膜技术用于自来水中丙烯酰胺的测定

开发了一种简便快速的固相萃取膜(SPE disk)技术,实现了对500 mL自来水中微量丙烯酰胺的富集,采用高效液相色谱法(HPLC)完成其定性和定量测定。比较不同填料的吸附情况,选择活性炭作为丙烯酰胺的最佳吸附剂。考察了洗脱剂种类、洗脱剂体积、洗脱速率和穿透体积等条件对萃取结果的影响,优化了色谱分离条件。经膜萃取过的丙烯酰胺在0.05～0.5 mg/L质量浓度范围内,其峰面积与质量浓度的线性关系良好,相关系数为0.998,检出限为20 ng/L。该方法对不同体积、不同浓度的丙烯酰胺溶液的回收率为94.12%～100.2%,相对标准偏差为2.09%～4.51%(n=3),自来水样品的加标回收率为79.96%。该方法操作简单、快速、灵敏度高,适合对水样中丙烯酰胺的测定。     

Retention studies of acrylamide for the design of a robust liquid chromatography-tandem mass spectrometry method for food analysis

A wide range of solid phases for SPE (solid-phase extraction) (n=14) and HPLC (n=9) were compared regarding the chromatographic retention of acrylamide. For SPE, a hydroxylated polystyrene-divinylbenzene copolymer phase (ENV+) gave the strongest retention. Twenty millilitre of water per gram solid phase could be passed with less than 5% loss of acrylamide from the column, thus enabling significant enrichment of food extracts. Other polymer phases gave varying degrees of retention, while silica bonded phases gave low retention. For HPLC, columns were evaluated both in reversed-phase and aqueous normal-phase (hydrophilic interaction chromatography) modes. The best retention was obtained with a phase comprising porous graphitic carbon (Hypercarb), giving a k-value of 4 with water as the mobile phase. Based on these investigations, a method for analysis of acrylamide in food using liquid chromatography-tandem mass spectrometry was designed to meet the demands of a collaborative validation trial. A comparative investigation of solid phases has not been published earlier. Thus, the paper should provide a base for new method developments regarding clean-up, enrichment and chromatography of acrylamide. In addition, the detailed standard operating procedure (SOP) method, as used in a collaborative validation trial, is provided as an electronic supplement (www.elsevier.com).     

Determination of acrylamide and methacrylamide by normal phase high performance liquid chromatography and UV detection

A method using normal phase high performance liquid chromatography (NP-HPLC) with UV detection was developed for the analysis of acrylamide and methacrylamide. The method relies on the chromatographic separation of these analytes on a polar HPLC column designed for the separation of organic acids. Identification of acrylamide and methacrylamide is approached dually, that is directly in their protonated forms and as their hydrolysis products acrylic and methacrylic acid respectively, for confirmation. Detection and quantification is performed at 200 nm. The method is simple allowing for clear resolution of the target peaks from any interfering substances. Detection limits of 10 microg L(-1) were obtained for both analytes with the inter- and intra-day RSD for standard analysis lying below 1.0%. Use of acetonitrile in the elution solvent lowers detection limits and retention times, without impairing resolution of peaks. The method was applied for the determination of acrylamide and methacrylamide in spiked food samples without native acrylamide yielding recoveries between 95 and 103%. Finally, commercial samples of french and roasted fries, cookies, cocoa and coffee were analyzed to assess applicability of the method towards acrylamide, giving results similar with those reported in the literature.     

Chromatographic determination of residual monomers in starch-g-polyacrylonitrile and starch-g-polyacrylate

Summary A reverse-phase HPLC method for simultaneous determination of acrylonitrile (AN), acrylamide (AM) and acrylic acid (AC) was developed. The residual monomer AC was quantified in several industrial polymers as well as grafted copolymers. Products of biodegradation of these copolymers were also identified.     

Novel polymer system for molecular imprinting polymer against amino acid derivatives

Molecular imprinting polymers (MIPs) against N-Cbz-L-Tyr were prepared utilizing different polymer systems and evaluated in HPLC mode. It was found that MEP utilizing cocktail functional monomers, acrylamide 2-vinylpyridine showed better molecular recognition and better separation ability for the template molecule than those utilizing other functional monomers. MIP utilizing trimethylolpropane trimethacrylate as cross-linker showed higher load capacity and separation factor than those utilizing ethylene glycol dimethacrylate as cross-linker. Increasing the concentration of competing solvent, acetic acid weakened the ionic interaction and hydrogen bonding between the analyte and the functional monomers, 2-vinylpyridine and acrylamide, when the template enantiomer was separated by HPLC. Therefore increasing of the concentration of acetic acid leads to decreasing of capacity factor, separation factor and resolution.     

Determination of acrylamide in Chinese traditional carbohydrate-rich foods using gas chromatography with micro-electron capture detector and isotope dilution liquid chromatography combined with electrospray ionization tandem mass spectrometry

The present study developed two analytical methods for quantification of acrylamide in complex food matrixes, such as Chinese traditional carbohydrate-rich foods. One is based on derivatization with potassium bromate and potassium bromide without clean-up prior to gas chromatography with micro-electron capture detector (GC-MECD). Alternatively, the underivatized acrylamide was detected by high-performance liquid chromatography coupled to quadrupole tandem mass spectrometry (HPLC-MS/MS) in the positive electrospray ionization mode. For both methods, the Chinese carbohydrate-rich samples were homogenized, defatted with petroleum ether and extracted with aqueous solution of sodium chloride. Recovery rates for acrylamide from spiked Chinese style foods with the spiking level of 50, 500 and 1000 μg kg⁻¹ were in the range of 79-93% for the GC-MECD including derivatization and 84-97% for the HPLC-MS/MS method. Typical quantification limits of the HPLC-MSMS method were 4 μg kg⁻¹ for acrylamide. The GC-MECD method achieved quantification limits of 10 μg kg⁻¹ in Chinese style foods. Thirty-eight Chinese traditional foods purchased from different manufacturers were analyzed and compared with four Western style foods. Acrylamide contaminant was found in all of samples at the concentration up to 771.1 and 734.5 μg kg⁻¹ detected by the GC and HPLC method, respectively. The concentrations determined with the two different quantitative methods corresponded well with each other. A convenient and fast pretreatment procedure will be optimized in order to satisfy further investigation of hundreds of samples.     

Isolation and Characterization of Acrylamidase from <Emphasis Type="Italic">Arthrobacter</Emphasis> sp. DBV1 and Its Ability to Biodegrade Acrylamide

Although acrylamide finds diverse industrial applications, its presence in the environment is hazardous due to its carcinogenic, neurotoxic, and teratogenic properties. In spite of the general toxicity of acrylamide in the monomer form, some microorganisms are able to use it as a source of energy by catabolizing it to ammonia and acrylic acid by means of acrylamidase (EC 3.5.1.4). The present work reports on a novel soil isolate as an acrylamide-degrading bacteria. Based on biochemical characterization and 16S ribosomal RNA (rRNA) gene sequence, the bacterial strain was identified as Gram-positive Arthrobacter sp. DBV1. The optimum growth conditions were found to be temperature (30 °C) and pH 6.0 to 7.0. Evaluation of the effect of concentration of acrylamide (10–50 mM) incorporated into minimal medium showed maximum growth of Arthrobacter sp. DBV1 at 30 mM acrylamide. The biodegradation of acrylamide was confirmed by HPLC analysis. Acrylamidase was isolated and characterized for temperature and pH optima, substrate specificity by using different amides, and the effect of different activators/inhibitors such as metal ions and amino acids. These finding suggests that the strain could be attractive for biodegradation of acrylamide from the environment and also possibly from foods containing preformed acrylamide.     

柱前衍生化-气相色谱-质谱法定量测定食品中丙烯酰胺的含量

建立了气相色谱-质谱(GC-MS)定量测定食品中丙烯酰胺含量的分析方法。选择13C3-丙烯酰胺作为内标物。通过超纯水提取食品中的丙烯酰胺,经正己烷脱脂两次后,在酸性条件下选用溴化钾/溴酸钾为衍生剂进行衍生化反应,再采用乙酸乙酯进行液-液萃取两次,最后用三乙胺将丙烯酰胺转化为更稳定的产物2-溴丙烯酰胺,利用质谱检测器在选择离子扫描模式下测定2-溴丙烯酰胺。该方法在0.05～2.00 mg/kg范围具有良好的线性(r2=0.9995);检出限和定量限分别达到3 μg/kg和7 μg/kg;回收率范围为62.7%～65.5%。通过与前期建立的液相色谱-串联质谱(HPLC-MS/MS)方法进行对比,该法在薯片和面包样品中丙烯酰胺的检测结果略偏高,是一种可以用于常见食品中丙烯酰胺含量测定的分析方法。