液质联用分离测定山西苦荞黄酮

采用液质联用仪对山西苦荞中的黄酮类化合物进行分离鉴定,发现山西灵丘地区产的苦荞提取液中黄酮类化合物以芦丁为主;并分离出5种黄酮类化合物,分别为六取代黄酮(万寿菊素-葡萄糖醛酸苷),槲皮素-3-芸香糖葡萄糖苷,芦丁、槲皮素和槲皮素-3-双鼠李糖苷,其中六取代黄酮(万寿菊素-葡萄糖醛酸苷)和槲皮素-3-双鼠李糖苷为首次发现;并测定出这5种黄酮类化合物的含量分别为3.03%、5.05%、63.23%、4.19%和6.19%.     

液质联用分析常见植物油甘油三酯

采用高效液相色谱-串联飞行时间质谱法分析了常见植物油如大豆油、芝麻油、花生油、特级初榨橄榄油、葵花籽油、玉米油、油茶籽油、棉籽油和菜籽油的甘油三酯。结果显示每种植物油甘油三酯的种类和含量均不相同。该方法测定甘油三酯有效可行,可为甘油三酯结构信息研究及油脂掺伪鉴别提供基础支持。     

液质联用方法测定微量银杏内酯

用液质联用方法测定了微量银杏内酯的含量,分析柱为Lichrospher C-18柱,流动相为甲醇-水,采用梯度洗脱,质谱作为检测器,选择离子采集方式.本方法测定银杏内酯的线性范围为0.12～68.0 μg/mL,相关系数为0.998 4～0.999 4,相对标准偏差为0.38%～0.44%.     

气质联用和液质联用在农残检测中的应用

结合国家标准GB/T 19648-2006、GB/T20769-2008讨论了气相色谱-质谱法和液相色谱-串联质谱法在农残检测中的实际应用。     

苦荞挂面加工过程中苦荞黄酮含量的变化及其评价研究

以苦荞粉、小麦粉为主要原料制作苦荞挂面,探讨苦荞挂面在加工过程中黄酮含量的变化规律及以黄酮作为标记物评价苦荞挂面中苦荞含量方法的可行性。结果表明:加水、和面、醒置、压延、干燥工艺前后的黄酮含量(干基)差异均不显著(p>0.05),苦荞黄酮在挂面加工过程中具有较好的稳定性;苦荞粉添加量与挂面中黄酮含量呈线性相关(R2=0.999)。将黄酮作为标记物来快速评价挂面中苦荞含量具有较好的可行性与应用前景。     

应用液质联用技术诊断两起河豚毒素食物中毒

目的 快速查明食物中毒的原因, 为中毒事件的调查提供技术支持。方法 通过现场流行病学调查分 析中毒原因, 运用液质联用方法对样品进行检测确证。结果 两起食物中毒样品均检出河豚毒素。结论 本方法检测快速、准确、结果可靠, 对快速查明中毒原因和患者的临床救治提供可靠的诊断依据。     

液质联用快速检测猪肉中的甲氧氯普胺

目的：建立液质联用快速检测猪肉中甲氧氯普胺含量的方法。方法：样品经乙腈提取,无水乙酸钠除水,正己烷除脂,浓缩,上机检测。经0.1%甲酸水+乙腈梯度洗脱,C₁₈色谱柱分离,进入三重四极杆质谱仪,正离子模式下,经电喷雾电离源检测。结果：检测结果表明在2～40 ng·mL^-1线性关系良好,检出限为0.220 μg·kg^-1。经回收实验,在高中低3个浓度下,回收率分别为61.0%,70.4%,82.9%。相对标准偏差为9.0%、7.6%、5.1%。结论：该方法适用于畜禽及水产品中肌肉组织的检测。     

液质联用法测定淀粉中的马来酸

采用HPLC-ESI-MS/MS联用技术,检测淀粉及其制品中马来酸残留量。样品经50%水-50%甲醇提取后,以C18柱为液相分离柱,以甲醇和1%甲酸为流动相,多反应监测模式测定马来酸,其定性定量离子对分别为114.9/71.0。马来酸含量在10~100ng/mL范围内具有良好的线性关系,测定下限(10S/N)为10ng/mL。以淀粉为基体,加入3种不同浓度水平的马来酸做加标回收试验,回收率在85%~100%,相对标准偏差(n=6)小于10%。该方法操作简单,结果准确,重现性好。     

禽畜肉中氯霉素残留量的液质联用分析方法

研究一种针对禽畜肉中氯霉素残留量的液质联用分析方法。采用乙酸乙酯萃取样品中的氯霉素,氮吹后用水溶解样品残渣,然后用正己烷除去样品溶液中的脂肪,对样品中的目标物进行净化前处理。以乙腈- 体积分数0.1%醋酸溶液作流动相,C18色谱柱对食品中的氯霉素残留进行分离,然后用电喷雾质谱负离子选择离子模式[ESI(-)-SIM]对氯霉素进行检测。本方法缩短了色谱分离时间,提高了检测灵敏度和分析结果可靠性,具有准确、快速以及灵敏度高的特点,能够适应大规模样品的快速分析要求。     

苦荞黄酮的测定方法

比较了定量测定苦养黄酮的两种比色方法,通过与HPLC测定结果对照、影响因素的探讨以及方法评价,提出AlCl3比色法比常用的NaNO2-Al(NO3)3法更适于苦荞黄酮的测定.该方法操作简便,结果准确可靠.     

苦荞中酚酸和原花色素的分析测定

采用了反相液相色谱法 (RP HPLC) ,结合二极管阵列检测器 (DAD)分析 ,测定了苦荞籽粒各部分 (壳、麸皮、外层粉、内层粉 )的酚酸和原花色素。测定结果表明 ,苦荞中的酚酸种类主要是苯甲酸类———原儿茶酸和对羟基苯甲酸 ;酚酸总量在 94.61～ 1745 .3 3mg/kg。原花色素含量在 0 .0 3 %～ 5 .0 3 %。     

温、湿度对贮藏苦荞品质的影响

本文研究了不同温、湿度条件下 ,贮藏不同时间后 ,苦荞籽粒中的游离脂肪酸、芦丁、叶绿素的变化 ,探讨了其作用机制。结果表明收获后的苦荞籽粒干燥至其水分含量 <14 % ,贮藏在Aw <0 .6 1相对干燥的低温环境中 ,利于品质保存。     

Determination of purine alkaloids and catechins in different parts of Camellia assamica var. kucha by HPLC‐DAD/ESI‐MS/MS

BACKGROUND: Kucha (Camellia assamica var. kucha) is a novel wild tea resource grown in China and a tea plant containing a sizable amount of theacrine (1,3,7,9‐tetramethyluric acid). High‐performance liquid chromatography (HPLC) analysis of purine alkaloids and catechins in young leaves of Kucha has been reported previously. However, the compositions of purine alkaloids and catechins in other parts of the plant remain unknown, and more information about the chemical constituents of Kucha is also necessary for further research and development of this new tea resource. RESULTS: Using HPLC with diode array detection coupled with electrospray ionisation tandem mass spectrometry (HPLC‐DAD/ESI‐MS/MS), three purine alkaloids, seven catechins and four non‐catechin phenolic compounds were identified or tentatively identified in Kucha. Purine alkaloids and catechins in leaves at different developmental stages, flowers, stems, pericarps and seeds of the plant were also quantified for the first time by the HPLC method, which was fully validated. Recoveries of the quantified compounds ranged from 96.67 to 104.33%. CONCLUSION: The results showed that the total contents of purine alkaloids and catechins were highest in young leaves of Kucha. Theacrine was detected in all parts of the plant and found to be most abundant in pericarps. Copyright © 2009 Society of Chemical Industry     

食品中苏丹红的HPLC/DAD/MS分离分析方法研究

本实验研究了一种针对食品中非法添加苏丹红的分析方法,采用固相萃取技术对样品进行前处理,然后用HPLC 对苏丹红样品进行分离,DAD 和MS 进行串联检测。提高了分析检测的准确性、可靠性。本方法灵敏度高,具有较高且稳定的回收率,精密度较好。分析应用结果令人满意。     

分光光度法测定显齿蛇葡萄总黄酮含量

用95%的乙醇为溶剂连续加热回流浸提显齿蛇葡萄幼嫩茎叶中有效成分,以二氢杨梅素为标样,选择波长294nm,采用三氯化铝分光光度法,建立显齿蛇葡萄总黄酮含量测定方法。实验结果表明:标液浓度在5～50μg/ml范围内,吸光度与浓度呈良好的线性关系,回归方程为A=3.166×10-3X-9.0×10-3,r=0.9999(n=5)。加样平均回收率为98.6%,RSD为2.54%。本法操作简便、快速、准确,可作为该药材质量评价方法。     

Determination of antioxidant activity and phenolic compounds of Muntingia calabura Linn. peel by HPLC‐DAD and UPLC‐ESI‐MS/MS

Antioxidant activity in Muntingia calabura Linn. peel was evaluated by DPPH radical, ORAC, ABTS cation radical, FRAP assays and total phenolic contents by different extraction conditions. In addition, a method for determination of phenolic compounds in calabura peel samples harvested in Brazil using methanol:water and magnetic stirring as the extraction method, HPLC‐DAD and UPLC‐ESI‐MS/MS analysis were developed. Calabura peel showed antioxidant activity for all extraction conditions and assays evaluated, the most polar solvents being more effective. The developed HPLC‐DAD method allowed the accurate determination of phenolic compounds, with recoveries in the range of 72–107% and precision values ≤4%, with exception for chlorogenic acid. Gallic acid was determined at the highest concentration levels, followed by myricetin, ferulic acid and vanillic acid. However, all the five proposed phenolic compounds were identified in calabura peel samples by UPLC‐ESI‐MS/MS. Thus, calabura peel, an uncommon edible fruit part, can be appointed as a rich source of phenolic compounds.     

大孔吸附树脂纯化乳苣多酚的研究

通过吸附和解吸附实验筛选适合乳苣多酚纯化的大孔吸附树脂并确定其最佳工艺。结果表明:D-101为乳苣多酚纯化的最佳树脂,在150min内达到吸附平衡,120min内解吸附平衡。最佳上样浓度为0.2mg·mL-1,pH4,解吸剂浓度为60%乙醇,洗脱速率为0.5mL·min-1,洗脱体积为3BV。紫外吸收表明纯化后乳苣多酚纯度得到提高。结果说明,D-101可用于乳苣多酚进一步纯化。     

苦荞提取液的抗氧化活性研究

本文研究了苦荞籽粒各部分提取液的抗氧化活性 ,抗氧化能力大小顺序为麸皮 >外层粉 >芦丁>壳 >心粉。提取液中的总酚含量在 2 .34～ 4 3.4 5mgGAE/ 10 0mL ,酚酸主要是原儿茶酸和对羟基苯甲酸 ,黄酮浓度在 4 .34～ 74 .35mg芦丁 / 10 0mL ,原花色素浓度在 0 .6～ 10 0 .6mg/ 10 0mL。提取液的抗氧化活性是总多酚共同作用的结果     

Identification and quantification of aroma compounds of tartary buckwheat (Fagopyrum tataricum Gaertn.) and some of its milling fractions

Tartary buckwheat (Fagopyrum tataricum) seeds have a strong aroma that characteristically differs from the aroma of common buckwheat (Fagopyrum esculentum). Its phytochemical background has only been recently investigated. The aim of this study was to identify and quantify individual compounds responsible for tartary buckwheat aroma. Volatiles from different samples (whole seed, flour, and husks) were extracted with simultaneous extraction and distillation by Likens-Nickerson apparatus and analyzed by GC-MS. A total of 48 compounds were quantified and their odor activity values (OAV) were calculated. OAV of 26 compounds was higher than 10; therefore, they significantly contribute to the overall tartary buckwheat aroma. The compounds with OAV > 500 were: (E,E)-2,4-decadienal, (E)-2-nonenal, 2-phenylethanol, (E,E)-2,4-nonadienal, hexanal, decanal, and nonanal. The most important difference from the aroma of common buckwheat is the absence of salicylaldehyde and presence of naphthalene. Salicylaldehyde could be proposed as a marker to detect contamination/adulteration of tartary buckwheat with common buckwheat. PRACTICAL APPLICATION: Buckwheat is becoming one of important alternative crops. Its products which are rich in proteins, fiber, vitamins, and antioxidants have been associated with healthy nutrition. Although tartary buckwheat is similar to more familiar common buckwheat, their characteristic aromas differ notably. This study expands recent research on aroma of tartary buckwheat tea to seed, flour, and husks, and suggests how products from different species of buckwheat can be distinguished by analysis of aroma compounds.     

不同溶剂提取乳苣的抗氧化作用研究

以乳苣全草为原料,75%乙醇为溶剂提取乳苣,提取液用不同极性溶剂依次萃取,得石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物,同时测定了各相提取物对羟自由基、超氧阴离子自由基、DPPH自由基的清除能力,并与VC进行比较。结果表明:各萃取物均具有一定的抗氧化活性,且随着浓度的增加而增强;对羟自由基的清除能力大小依次为乙酸乙酯萃取物>正丁醇萃取物>VC>水萃取物>石油醚萃取物;对超氧阴离子自由基清除能力大小依次为VC>正丁醇萃取物>乙酸乙酯萃取物>石油醚萃取物>水萃取物;对DPPH自由基清除能力大小依次为VC>乙酸乙酯萃取物>正丁醇萃取物>水萃取物>石油醚萃取物;各萃取物还原能力大小依次为VC>正丁醇萃取物>乙酸乙酯萃取物>水萃取物>石油醚萃取物。