GPC–HPLC–MS/MS法测定食用油中天然辣椒素、二氢辣椒素和合成辣椒素含量

以动植物油脂为实验材料,建立了测定食用油中天然辣椒素、二氢辣椒素和合成辣椒素含量的凝胶渗透色谱–高效液相色谱–串联质谱(GPC–HPLC–MS/MS)法。样品经凝胶渗透色谱净化后,采用液相色谱串联质谱法(HPLC–ESI–MS/MS)分析,多反应监测模式(MRM)下外标法定量。在0.1~5.0μg/L范围内线性良好,天然辣椒素、二氢辣椒素和合成辣椒素的相关系数分别为0.999 6,0.999 8,0.999 8,检出限为0.5μg/kg。在5μg/kg添加水平下,空白加标回收率为71.5%~82.5%,测定结果的相对标准偏差为3.0%~8.3%(n=6)。该方法样品处理过程简便快捷,测定结果准确,可满足实验室大量、快速分析的需求。     

LC-MS/MS鉴别地沟油新方法

建立了高效液相色谱-串联质谱(LC-MS/MS)同时测定地沟油中辣椒素、二氢辣椒素及胡椒碱3种难挥发性微量杂质成分的方法。样品采用正己烷饱和的乙腈提取,经Thermo BDS Hypersil C18(100 mm×2.1 mm,2.4μm)色谱柱梯度洗脱分离,在电喷雾正离子模式下以多反应监测(MRM)方式采集数据进行定性定量测定。3种地沟油特征物质在相应的浓度范围内呈良好线性,相关系数(r2)均大于0.99,在3个不同加标水平下,平均回收率为65%～89%,相对标准偏差(RSD)为5.3%～16.1%,检出限(LOD,S/N≥3)和定量下限(LOQ,S/N≥10)分别为0.03、0.1μg/kg。实际样品测试表明,该方法简便快速、灵敏可靠,可作为地沟油鉴别的重要手段之一。     

高效液相色谱法测定富含油脂辣椒制品中的辣椒素类物质

建立了高效液相色谱法测定高油脂辣椒制品中3种主要辣味成分的方法.样品以70%乙醇提取,采用反相高效液相色谱分离,紫外检测器;根据色谱峰的保留时间定性,以外标峰面积法定量辣椒素(C)、二氢辣椒素(DC)、去甲二氢辣椒素(NDC),结果以斯氏指数(SHU)计.NDC的色谱行为与C极其类似,NDC可采用C的标准曲线定量.采用色谱柱,ZORBAX SB-C18;流动相,V(甲醇)∶V(水)=70∶30;UV检测波长,230 nm;辣椒素和二氢辣椒素RSD分别为1%,1.5%(n=5);回收率分别为97.5%、94.5%.辣椒素和二氢辣椒素在0.001～0.1 mg/mL范围内线性良好;LOD 0.1 mg/L,LOQ 0.5 mg/L.供试品溶液稳定,12 h内测定RSD为1%.方法满足辣味水平评价要求.     

高效液相色谱法测定高含水量辣椒制品中的辣椒素类物质

样品以70%乙醇提取,采用反相高效液相色谱分离,色谱条件:色谱柱ZORBAX SB C184.6 mm×250mm,5μm;流动相为甲醇-水(体积比70∶30);流速0.8 mL/min;UV230 nm检测;进样量20μL。以外标峰面积法定量辣椒素(C)、二氢辣椒素(DC)、去甲二氢辣椒素(NDC),结果以斯氏指数(SHU)计。NDC的色谱行为与C极其类似,NDC采用C的标准曲线定量。C和DC的RSD分别为1.0%、1.5%(n=5);平均回收率分别为97%、96%。C和DC在0.001~0.1 g/L范围内线性良好;检出限(LOD)为0.1 mg/L,定量下限(LOQ)为0.5 mg/L。方法满足辣味水平评价要求。     

超高效液相色谱法快速测定辣椒素类物质

建立了超高效液相色谱法快速测定辣椒制品中辣椒素、二氢辣椒素、降二氢辣椒素的方法.样品以四氢呋喃-甲醇(体积比1:1)提取,采用反相高效液相色谱分离.色谱柱为BEH C18,流动相乙腈-水进行梯度洗脱;二极管阵列检测器(DAD),检测波长为280 nm.各成分在1.0 -100.0 mL/L范围内线性良好.辣椒素、二氢辣...     

无溶剂微波预处理-NaOH溶液搅拌法提取干红辣椒中的辣椒素

将无溶剂微波预处理与NaOH搅拌提取相结合提取辣椒素类物质(Capsaicinoids)。在干辣椒样品中加入微波吸收介质羰基铁粉(CIP),对干辣椒样品进行微波预处理。根据辣椒素与NaOH之间可发生特异性反应,利用NaOH溶液从辣椒中提取两种主要的辣椒素类化合物---辣椒素(Capsaicin,C)和二氢辣椒素(Dihydrocapsaicin,DHC)。实验表明,本方法提取时间短(10min),提取率高,并可有效避免有机溶剂对实验室的污染。     

辣椒素酯类物质的酶促合成

天然辣椒素酯类物质(Capsinoids)是从日本的一种甜椒中分离得到的结构类似辣椒的酯类物质[1,2],包括辣椒素酯(Capsiate)、二氢辣椒素酯(Dihydrocapsiate)及降二氢辣椒素酯(Nordihydro-capsiate),为相对应的辣椒素的脂肪酰基与香草醇形成的酯类化合物(结构如图1)。无辣味,生物活     

应用制备高效液相色谱同时制备6种大豆异黄酮单体的方法研究

经大孔吸附树脂纯化大豆异黄酮粗提物后,以制备型高效液相色谱法(PHPLC)分离得到高纯度的大豆异黄酮单体。以SHIM-pack PRC-ODS(20 mm×250 mm,5μm)制备柱,考察了流动相组成及流速、进样量对分离度的影响,确定了最佳色谱条件为乙腈-水流动相梯度洗脱,进样量800μL,流速10 mL/min,在120 min内实现了6种异黄酮单体的基线分离及制备。经超高效液相色谱-串联质谱(UPLC-MS/MS)鉴定,6种异黄酮单体依次为大豆苷、黄豆黄苷、染料木苷、大豆素、黄豆黄素、染料木素。6种产品的纯度分别为95.54%、90.14%、100%、100%、96.27%、100%。方法具有简便易行、稳定性好、产品纯度高等特点,适用于大豆异黄酮标准品的制备。     

反相高效液相色谱法制备纯化大豆异黄酮糖苷

利用制备高效液相色谱法从大豆总异黄酮提取物中制备出了3种大豆异黄酮糖苷。在Nova-Pak HR C18色谱柱(100 mm×25 mm i.d.,6 μm)上,以甲醇-体积分数为0.1%的乙酸水溶液(体积比为23∶77)为流动相,流速为20 mL/min,采用 等度洗脱方式,制备了3种大豆异黄酮糖苷,经质谱分析,确认它们分别为大豆苷、黄豆苷和染料木苷。高效液相色谱分析 表明,所制备的3种化合物的纯度均达到了99%以上。     

应用制备高效液相色谱同时制备6种大豆异黄酮单体的方法研究

经大孔吸附树脂纯化大豆异黄酮粗提物后,以制备型高效液相色谱法(PHPLC)分离得到高纯度的大豆异黄酮单体。以SHIM-pack PRC-ODS(20 mm×250 mm,5 μm)制备柱,考察了流动相组成及流速、进样量对分离度的影响,确定了最佳色谱条件为乙腈-水流动相梯度洗脱,进样量800 μL,流速10 mL/min,在120 min内实现了6种异黄酮单体的基线分离及制备。经超高效液相色谱-串联质谱(UPLC-MS/MS)鉴定,6种异黄酮单体依次为大豆苷、黄豆黄苷、染料木苷、大豆素、黄豆黄素、染料木素。6种产品的纯度分别为95.54%、90.14%、100%、100%、96.27%、100%。方法具有简便易行、稳定性好、产品纯度高等特点,适用于大豆异黄酮标准品的制备。     

Determination of Capsaicinoids in Red Pepper Products from South Korea by High-Performance Liquid Chromatography with Fluorescence Detection

This study aimed at determining the concentrations of the major capsaicinoids, namely, capsaicin and dihydrocapsaicin, in commonly consumed red pepper products from South Korea. The capsaicinoids were extracted with 95% methanol and determined by high-performance liquid chromatography with florescence detection. The analytical method was validated by quality assurance parameters such as the linearity, limits of detection and quantification, precision, and accuracy. Satisfactory results were obtained in accordance to the specified criteria for application of analytical techniques in food. The concentration of capsaicinoids was the highest for red pepper powder (4.18–139.4?mg/100?g), followed by gochujang (0.93–23.20?mg/100?g), kimchi (0.05–1.16?mg/100?g), and sliced kimchi (0.06–0.88?mg/100?g). Comparing the capsaicinoid contents in samples from different production areas, no significant differences were found. This research concluded that the capsaicinoid content of red pepper products provided valuable information regarding the samples.     

Capsaicinoids in Chili Habanero by Flow Injection with Coulometric Array Detection

This study presents a sensitive electroanalytical method for the determination of capsaicinoids in chili extracts using flow injection with coulometric array detector. Flow injection method was developed based on the coulometric signal of capsaicinoids obtained by high performance liquid chromatography with coulometric detector (HPLC‐ECD). Capsaicinoids concentration in 18 chili samples from Yucatán México cultivated in different types of soils was quantified using UHPLC‐DAD and HPLC‐ECD and expressed in Scoville units. The plants were cultivated in a greenhouse on three types of limestone soils, namely, red, black and brown. Chili peppers were harvested in two stages of maturity: immature (green), and mature (orange). HPLC‐ECD method showed ten times higher sensitivity compared to the UHPLC‐DAD. Capsaicinoid content in 18 chili samples was measured by flow injection method. The best correlation with the Scoville units was obtained by the analysis of the current signal of the sensor poised at +450 mV (R²=94). ANOVA analysis showed that the soil type and the harvest date were significant for the capsaicinoid content. Chili plants cultivated in red soil had higher capsaicinoid content. In addition, the capsaicinoid content was increasing at later harvest dates. In summary, the suggested flow injection method with coulometric array detector decreased the time of analysis from 15 min to 30 s. Therefore it can be successfully applied for the routine capsaicinoid analysis in chili.     

Determination of Three Capsaicinoids in Raw Red Pepers and Seasoning Powders by Liquid Chromatography with Coulometric Detection

The simultaneous determination of three capsaicinoids in raw red pepper and in foods was studied by liquid chromatography coupled to a coulometric detector. The capsaicinoids were separated on an ODS C18 reversed column by isocratic elution with a mobile phase based on acetonitrile −0.15 M acetic acid (51:49%, v/v) at a flow rate of 0.8 mL min⁻¹. The limit of detection (S/N> 3) was 10 pg (injected mass) at an applied potential of 0.650 V vs. Pd. The peak area of the three studied compounds was found to be related to the amount injected from 50 pg to 100 ng range (r=0.999). The relative standard deviation (RSD, n=10) was comprised between 1.5∼4.4 and 1.0∼3.5 % for 100 pg and 5 ng, respectively. The determination of three capsaicinoids in raw red peppers and red pepper containing foods was successfully realized.     

Isolation of individual capsaicinoids from a mixture and their characterization by (13)C NMR spectrometry

Individual compounds were isolated from a laboratory mixture of capsaicinoids by a multi-stage approach. First, the capsaicinoids were fractionated into capsaicins and non-capsaicins by argentation solid phase extraction (SPE) on a silver-charged propyl sulfonate resin. Second, compounds in each fraction were isolated by semi-preparative liquid chromatography on a C₃₀ phase in aqueous methanol. Third, the individual components of the original mixture were concentrated by reversed phased (C₁₈) SPE. The structure of each purified compound was confirmed by ¹³C NMR spectrometry and spectral comparison to known standards, purchased or synthesized locally. The chemical shifts of 15 capsaicinoid standards were measured on a 600 MHz instrument, and their assignments to particular carbons were made by reference to Distortionless Enhancement by Polarization Transfer (DEPT) NMR experiments and NMR spectral prediction software.     

Dispersive liquid-liquid microextraction for the isolation and HPLC-DAD determination of three major capsaicinoids in Capsicum annuum L.

Dispersive liquid-liquid microextraction (DLLME) was combined with high-performance liquid chromatography-diode-array detector (HPLC-DAD) for the extraction and quantitation of three major capsaicinoids (i.e. capsaicin, dihydrocapsaicin and nordihydrocapsaicin) from pepper (Capsicum annuum L.). Chloroform (extraction solvent, 100 μL), acetonitrile (disperser solvent, 1250 μL) and 30 s extraction time were found optimum. The analytes were back-extracted into 300 μL of 50 mM sodium hydroxide/ methanol, 45/55% (v/v), within 15 s before being injected into the instrument. Enrichment factors ranged from 3.3 to 14.7 and limits of detection from 5.0 to 15.0 µg g^-1. Coefficients of determination (R²) and %RSD were higher than 0.9962 and lower than 7.5%, respectively. The proposed method was efficiently applied for the extraction and quantitation of the three capsaicinoids in six cultivars of Capsicum annuum L. with percentage relative recoveries in the range of 92.0%–108.0%. DLLME was also scaled up for the isolation of the three major capsaicinoids providing purity greater than 98.0% as confirmed by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) analysis, which significantly reduced the extraction time and organic solvent consumption.     

工业制备高效液相色谱法制备淫羊藿中的黄酮系列对照品

淫羊藿甙和朝藿定A、B、C是淫羊藿中重要的活性成分,本研究应用工业制备高效液相色谱从淫羊藿粗提物中分离制备了这4个成分。淫羊藿粗提物经大孔吸附树脂粗分离获得相应的组分后,利用工业制备高效液相色谱完成精制纯化。采用自装填Chromatorex C18制备柱(220 mm×77 mm, 10 μm),乙腈-水(26:74或30:70, v/v)为流动相进行洗脱,在35 min内,实现了这4种成分的基线分离及规模制备。从300 g粗提物(总黄酮含量约20%)中获得淫羊藿甙33 g、朝藿定C 4.6 g、朝藿定B 3.7 g和朝藿定A 0.6 g,产品纯度均达到98%以上。此方法通过两步分离即可实现这4种成分的完全分离,具有快速高效、产品纯度高的特点,适于淫羊藿中淫羊藿甙、朝藿定A、B、C系列对照品的规模制备。     

制备色谱法分离纯化高良姜黄酮中高良姜素和山柰素

建立了制备型高效液相色谱(Prep-HPLC)分离高良姜黄酮中高良姜素和山柰素的方法。高良姜黄酮经HPD-600树脂吸附洗脱纯化后,采用Prep-HPLC分离高良姜黄酮中高良姜素和山柰素。制备色谱条件:流动相为甲醇-0.6%(v/v)乙酸水溶液(58:42, v/v),柱温为常温,流速为7.0 mL/min,检测波长为360 nm,进样量为700 μ L,上样质量浓度为10.0 g/L。分离的单体由质谱和核磁共振氢谱、碳谱鉴定确证为高良姜素和山柰素,HPLC外标法定量,纯度分别为99.5%和99.7%。该方法分离效果好、高效、低毒,可用于高良姜中高良姜素和山柰素的分离制备。     

Reversed-phase liquid chromatography and argentation chromatography of the minor capsaicinoids

An investigation of the liquid chromatography of the minor capsaicinoids in a commercial capsaicinoid mixture is reported. Twelve stationary phases including C₈, C₁₈, C₃₀, phenyl, and cation-exchange chemistries were examined in combination with isocratic aqueous methanol and aqueous acetonitrile mobile phases. A phenyl stationary phase and aqueous acetonitrile mobile phase baseline-resolved 7 of 11 capsaicinoids, and selected ion chromatograms (LC–ESI-MS) demonstrated this was the most effective reversed-phase separation. Argentation chromatography with an alkyl or phenyl column and aqueous silver nitrate–methanol mobile phase revealed the presence of the 6-ene-8-methyl and 6-ene-9-methyl homocapsaicin isomers and the absence of 7-ene-9-methyl homocapsaicin. A mixed phenyl–cation-exchange stationary phase (charged with silver ion) enabled unique and useful separations of the capsaicinoids.     

Separation and purification of intermediates for the preparation of naproxen from synthetic mixtures by countercurrent chromatography

Three key intermediates in the preparation of the nonsteroidal anti‐inflammatory drug naproxen were successfully separated and purified with high purity from synthetic mixtures by countercurrent chromatography with a selected biphasic solvent system. The biphasic solvent system composed of n‐hexane/ethyl acetate/methanol/water (9:1:9:1, v/v/v/v) was selected according to partition performance of the three components using thin‐layer chromatography. Fifty milligrams of the synthetic mixture after the three‐step reaction was injected into a preparative countercurrent chromatography separation column and yielded 3.5, 14.0, and 8.0 mg of three key intermediates with 95.0, 99.0, and 98.0% purity, and the recovery of each component was 65.2, 71.2, and 69.6%, respectively. The results indicated that countercurrent chromatography is an efficient alternative and economical method for the separation and purification of intermediate components from synthetic mixtures.