高效液相色谱法测定月饼中山梨酸

山梨酸及其钾盐,毒性小,抗菌力强,是月饼中最常使用的防腐剂。目前,山梨酸的测定方法主要有气相色谱法、高效液相色谱法和薄层色谱法[1 ] 。由于月饼中蛋白质及油脂含量高,直接用乙醚萃取气相色谱测定,萃取效率低;用玻璃纸层析除去蛋白脂肪,回收率低且费时。本文根据山梨酸具有挥发性的特点[2 ] ,采用水蒸气蒸馏法,除去蛋白质及油脂,用高效液相色谱法测定,结果准确,重现性好。1　材料与方法1.1　仪器与试剂　LC -10A高效液相色谱仪;硫酸钠溶液:5 0 0g/L。山梨酸标准储备液(1.0mg/ml) :准确称取0 .10 0 0g山梨酸标准品,加5ml碳酸氢钠溶液(2…     

高效液相色谱法测定蜂胶中双胍类与噻唑烷二酮类合成降糖药物

目的建立快速分离蜂胶组分,高效液相色谱法测定蜂胶中非法添加的二甲双胍、苯乙双胍、盐酸吡格列酮和盐酸罗格列酮等4种化学合成降糖药物的方法。方法采用薄层色谱系统对蜂胶进行双向展开、分离、显色及刮板,提取后用高效液相色谱法进行检测。结果蜂胶组分能被有效分离,4种化学合成降糖药物均被检出;薄层色谱法将蜂胶中的组分分离后,用高效液相色谱法检测各组分的检出限:二甲双胍、苯乙双胍和盐酸罗格列酮的检出限均为0.1μg/mg,盐酸吡格列酮的检出限为0.2μg/mg;薄层色谱法中4种降糖药的检出限均为2μg/mg;回收率为65.0%~101.2%,相对标准偏差为2.2%~18.0%。结论本方法操作简单,方便快捷,准确性好,可用于检测蜂胶中非法添加的双胍类和噻唑烷二酮类合成降糖药物。     

高效液相色谱测定食品中苯甲酸、山梨酸含量

目的　测定食品中山梨酸、苯甲酸的含量。方法　样品用乙醚—石油醚萃取 ,在 6 0℃水浴上蒸馏除去乙醚—石油醚 ,再在酸性介质中酯化 ,用高效液相色谱分离与测定。结果　标准回收率 :苯甲酸 (10 0 .0 2± 3.2 8) % ,山梨酸 (96 .3± 4 .85) %。最小检出限分别为 :苯甲酸 0 .0 2 2 μg ,山梨酸 0 .0 13μg ,线性关系与回收率较好 ,(r >0 .98)。结论　HPLC法测定食品中苯甲酸与山梨醇防腐剂具有简便、快速、准确的优点 ,值得推广应用     

织纹螺毒素的液相色谱法测定

目的:建立高效液相色谱法检测织纹螺中毒素的方法.方法:取织纹螺肉20 g,用60 ml含1%醋酸的甲醇溶液分3次抽提,离心分离合并上清液,在40℃真空旋转蒸发器中浓缩至近干,加蒸馏水溶解,三氯甲烷脱脂,水层经过活性炭柱吸附,用1%醋酸乙醇洗脱,再经过Bio-Gal P-2(2×98 cm)柱中精制,精制液用Bio-Rex 70(1×100 cm)酸性凝胶柱控制流量在0.5 ml/min下采用线性为0～0.03 mol/L甲酸进行分割,收集的分割液经冷冻干燥,用1%醋酸定容,在高效液相色谱仪的反相色谱柱RP-18分离,荧光检测器定量检测.结果:本方法测定TTX的RSD为8.75%,平均样品加标回收率为82.5%,最低检出限2.1 μg;anh-TTX的RSD为5.25%,平均样品加标回收率为90.1%,最低检出限12.5 μg;GTX的RSD为7.23%,平均样品加标回收率为83.0%.最低检出限1.7 μg;STX的RSD为5.93%,平均样品加标回收率为101.3%,最低检出限4.2μg.结论:(1)采用活性炭吸附,经Bio-Gal P-2(2×98 cm)柱和Bio-Rex70(1×100 cm)柱处理的样品.在液相色谱检测时,可以有效消除来自样品基体背景的严重干扰,使样品待测组分分析图谱与加标方法制备的标准分析图谱具有同样的抗干扰性.(2)分别采用两种流动相可以准确分析TTX、anh-TTX、GTX和STX毒素.(3)使用改制的柱后衍生系统能够方便、价廉的满足检测工作需要.解决了样品前处理中有效排除样品基体干扰物质的问题,使净化的待测定毒素成分能够采用高效液相色谱仪的反相色谱柱定量检测.     

高效液相色谱-串联质谱法测定谷物中呕吐毒素及其衍生物

目的 建立同位素稀释-高效液相色谱-串联质谱法测定谷物中呕吐毒素及其衍生物残留量的方法。 方法 样品经(86+14,v/v)乙腈水超声提取,HLB小柱净化,经C18色谱柱分离后,在质谱负离子多反应监测模式下测定。 结果 DON和3-ADON在2.0~500 μg/L,15-ADON在10.0~1 000 μg/L时,具有良好的线性关系,相关系数(r)均大于0.9990。DON及其衍生物的LOD在0.10~1.6 μg/kg之间,LOQ在0.35~6.0 μg/kg之间,加标回收率范围为80.3%~115.4%,相对标准偏差(RSD,n=6)在5.1%~14.6%之间。 结论 该方法快速简便,定量准确,可满足谷物中呕吐毒素及其衍生物的残留检测要求。     

维生素B_1、C和鲜桔汁对人肺癌细胞的作用

目的 :　观察维生素 B1、C及富含维生素 C的鲜桔汁在体外对人肺癌细胞 YTMLC-90生长的影响。方法 :　实验分 4组 :溶剂对照组 ,鲜桔汁组 (含维生素 C终浓度 30 ,60 ,1 2 0 μg/ml) ,维生素 C组 ( 30 ,60 ,1 2 0 μg/ml) ,维生素 B1组 ( 0 .0 1 ,0 .1 ,1 μg/ml)。实验方法包括四唑盐( MTT)比色实验 ,集落形成实验和 3H- Td R掺入实验。鲜桔汁中维生素 C含量及培养基中维生素 C稳定性用高效液相色谱法 ( HPLC)测定。结果与结论 :　以上三项实验均显示鲜桔汁、维生素 C及B1对人肺癌细胞 YTMLC- 90生长有一定抑制作用 ,且呈剂量 -效应和时间 -效应关系 ;维生素 B1、C的抑癌作用在 72 h后才能显示出 ;鲜桔汁组抑癌作用强于纯品维生素 B1和 C组。     

保健食品中大豆异黄酮的测定方法研究

〔目的〕检测保健食品中黄豆甙、黄豆甙元、染料木甙和金雀异黄素 ,建立保健食品中四种大豆异黄酮的二极管阵列检测器高效液相色谱法。〔方法〕样品用甲醇 水 (80 2 0 ,v/v)超声提取 3 0min ,定容后过 0 .45 μm滤膜 ,上 2 5 0×4.6mm ,粒径 10 μm的C18柱 ,以甲醇 0 .0 5 0mol/L ,pH4.6醋酸铵 (4 6 5 4,v/v)作流动相 ,二极管阵列检测器测定。测定时间只需 2 0min左右 ,黄豆甙 ,染料木甙 ,黄豆甙元和金雀异黄素可得到良好分离。〔结果〕黄豆甙 ,染料木甙 ,黄豆甙元和金雀异黄素的加标回收率分别为 90 .4%～ 10 2 % ,88.9%～ 10 2 % ,93 .0 %～ 10 2 % ,89.3 %～ 10 4% ,加标回收相对标准偏差均小于 6% ,最底检出浓度均为 0 .10 μg/ml。〔结论〕本方法适用于保健食品中大豆异黄酮的测定     

检测五指毛桃有效成分含量的标准方法研究

目的 建立鉴定五指毛桃质量的标准化测定方法。 方法 采集广东等地的道地药材;对采集到的五指毛桃中药材进行品种、性状、来源研究,采取薄层色谱层析(TLC)法对提取物中的五指毛桃进行定性鉴别;用紫外分光光度法测定有效部位补骨脂素的含量;用高效液相色谱(HLP)法测定补骨脂素的含量。 结果 在薄层色谱法图谱中可检出五指毛桃的特征斑点,实现定性检测;补骨脂素在7.362～32.965 μ/mL间线性关系良好,r=0.9995,平均回收率为96.845%,RSD=1.08%(紫外分光光度法);补骨脂素在0.854 μg～2.632 μg间线性关系良好,r=0.9998,平均回收率为98.364%(高效液相色谱法),RSD=0.8%。 结论 所建立的检测程序可行、重现性好,能有效地鉴定中药提取物中五指毛桃的质量。     

高效液相色谱法检测肉类食品中盐酸克仑特罗含量

应用高效液相色谱法检测肉类食品中盐酸克仑特罗含量。采用甲醇 -乙醇 -水混合溶剂、以高速组织捣碎机和超声波仪提取 ,调至 pH11以上后用乙醚萃取、挥干、溶解定容 ;再以C18液相色谱柱、用 0 .0 2mol/L磷酸二氢钾 +甲醇 (65 +3 5 )做流动相、在 2 10nm波长进行检测。该方法的工作曲线范围是 0 .0～ 5 0 .0 μg/ml,其相关系数γ =0 .9999,回归方程 y =[4 .92 2 7e +0 4]X +1679;最低检出限 0 .0 7μg/ml;相对标准偏差为 3 .6%～ 5 .8% ;回收率为 90 .0 6%～ 10 0 .2 3 % ,平均为 95 .6%。该方法具有灵敏、准确、快速、稳定的特点。     

高效液相色谱法测定木糖醇

木糖醇广泛应用于食品和医药行业 ,木糖醇的测定在“国标”中为气相色谱法 ,采用高效液相色谱法测定木糖醇在某些单位也曾试用 ,但未建立起一套完整的测定方法。本实验室经过大量研究和实验 ,总结并建立了高效液相色谱法测定木糖醇〔1〕。1　材料和方法1 1　仪器 :Waters液相色谱仪 ,6 0 0E泵 ,示差检测器 ,AminexHPX - 87CcarbohydrateColumn ,30 0mm×7 8mm ,数据处理工作站 ,0 4 5 μm滤膜。1 2　试剂 :乙腈 (色谱纯 ) ,高纯水 (二次石英蒸馏 ) ,木糖醇、阿拉伯醇、卫茅醇、甘露醇、山梨醇 ,纯度均大于 99%,购于美国Sigma公司。…     

A simplified method for rapid determination of porphyrins by thin-layer chromatography.

Free porphyrins, especially copro-, uro-, and protoporphyrin, were successfully separated by talc thin-layer chromatography (TLC), and were determined from the relationship of the weight and the area of porphyrins in the spot on the thin-layer plate. The results obtained from both the solvent extraction and the simple, rapid TLC method reported in this paper showed good correlation for coproporphyrin levels up to 400 microgram/1. The TLC method was applied to the determination of urinary coproporphyrin in lead workers and in rats.     

A simplified method for rapid determination of porphyrins by thin-layer chromatography

Free porphyrins, especially copro-, uro-, and protoporphyrin, were successfully separated by talc thin-layer chromatography (TLC), and were determined from the relationship of the weight and the area of porphyrins in the spot on the thin-layer plate. The results obtained from both the solvent extraction and the simple, rapid TLC method reported in this paper showed good correlation for coproporphyrin levels up to 400 microgram/1. The TLC method was applied to the determination of urinary coproporphyrin in lead workers and in rats.     

Automatic spotting of pesticide extracts on thin-layer plates

Summary An apparatus has been devised to apply on a thin-layer sheet 9 samples of 1 or 2 ml of a solvent extract at a rate of 1 ml/20 to 30 min, thereby allowing the solvent to be evaporated by an airstream. Spots were 5 to 6 mm in diameter, and no attention of the analyst was required during spotting. The apparatus has been used to analyze for chlorinated hydrocarbons in soils.     

Monomethylformamide levels in human urine after repetitive exposure to dimethylformamide vapor

Eight healthy male subjects were exposed to DMF vapor at a concentration of 8.79 +/- 0.33 ppm for six hours daily for five consecutive days. All urine voided by the subjects was collected from the beginning of the first exposure to 24 hours past the end of the last exposure and each sample was analyzed for monomethylformamide (MMF). MMF was rapidly eliminated from the body with urine values peaking within a few hours following the end of each exposure period. Very little was found in the 24-hour postexposure sample and none was found in a 48-hour postexposure sample. There was no increased excretion of MMF in the urine following repetitive exposure. The mean for the seven-hour (end of exposure) sample was 4.74 microgram/ml or 736.8 microgram. Lower and upper one-sided 95% tolerance limits for 95% of the population were 1.2 microgram/ml (367 microgram) and 13.9 microgram/ml (1625 microgram). The coefficient of variation (CV) for microgram MMF/ml was approximately 25 times more variable than the CV for total microgram.     

绿茶中阻断亚硝胺合成的有效成分的分离鉴定

茶叶用沸水(1:10)提取10 min,过滤并冷冻干燥(Ⅰ);另将茶水用氯仿、乙酸乙酯先后提取浓缩,并与残水一起分别冷冻干燥,得组分Ⅱ、Ⅲ、Ⅳ。用Sephadex LH20对组分Ⅱ分离,以2 ml/min流速用氯仿:甲醇:石油醚(1:2:1)洗脱,监测280 nm处紫外吸收以收集馏分。对馏分F_(7～10)浓缩、纯化与重结晶,经UV和MS分析并与茶儿茶素标准相对照,F_7为(一)-表儿茶素(EC)和(一)-儿茶素(C), F_8为(一)-表没食子儿茶素(EGC), F_9为(一)-表儿茶素没食子酸酯ECG,F_10为(一)-表没食子儿茶素没食子酸酯(EGCG);HPLC测定其纯度,F_7为17％C和83％EC,F_8为99％以上EGC,F_9为92.5％ECG,F_10为93.6％EGCG。茶叶中阻断N-亚硝化的主要有效成分为茶多酚(组分Ⅲ),尤为茶儿茶素混合物;茶儿茶素的阻断能力与其与NO_2~-摩尔比及本身的抗氧化能力有关。     

中药远志提取物体外杀精子效果与机制研究

目的:通过精子低渗肿胀(HOS)实验结合改良伊红染色法观察中草药远志粗提物体外杀精活性及机制。方法:HOS实验结合伊红-姬姆萨(EG)染色(HOS-EG)判断精子膜完整性,将精子分为A(HOS+-EG-)、B(HOS-EG-)、C(HOS+-EG+)、D(HOS-EG+)4型。精子染色质扩散实验(SCD)检测精子DNA碎片。制备远志粗提物,并判断其体外杀精子活性。壬苯醇醚-9(N-9)作为标准参照物,生理盐水为对照组。结果:远志粗提物浓度为50.0mg/ml和20.0mg/ml时体外20s内即可完全杀灭精子(与精液1:1混合)。对照组、远志粗提物组及N-9组精子DNA碎片比例各组比较无差异。对照组A、B、C和D型精子百分比分别为(69.0±8.3)%、(3.4±0.5)%、(10.2±1.7)%和(17.4±2.1)%。远志粗提物组及N-9组精子膜完整性全部被破坏,无A型和B型精子,C型精子较对照组明显减少,D型精子比对照组明显增加(P<0.001)。精子复活实验显示远志粗提物组和N-9组均无活动精子恢复。结论:HOS-EG实验可以同时判断一条精子头膜或尾膜损伤。远志粗提物在体外通过破坏精子膜使精子快速失活。     

Mycotoxins in enzyme preparations. Part II. Method of detection and determination of sterigmatocystin]

A simple method for the detection and semiquantitative determination of sterigmatocystin in enzyme preparations was described. The method comprises extraction with acetonitrile and a 4% aqueous KCL solution, column chromatographic purification of the crude extracts on silica gel, and two-dimensional thin-layer chromatography. The mean recovery by this method is from 71 to 79%, and the detectability of sterigmatocystin is 20 micrograms/kg.     

Studies on procedure for sample preparation of ellagic acid in several kinds of foodstuffs

A sample preparation for ellagic acid in several kinds of foodstuffs, which is included in the List of Existing Food Additives as natural antioxidants in Japan, functioning as an antioxidant, was studied. The solid samples were refluxed with methanol, and then the extract was refined using a solid-phase cartridge. The liquid samples were directly pretreated by solid-phase extraction. On the other hand, test solutions for cooking oils and fats were inapplicable to solid-phase extraction in this work, because the recovery tests from samples spiked with ellagic acid gave low recoveries. Consequently, they were prepared by modified frozen method using methanol or acetonitrile-2-propanol-ethanol (2:1:1). The recoveries from tested foodstuffs spiked with ellagic acid (50 micrograms/g) were 75.2-96.9%. The limits of quantification for ellagic acid were 0.05 microgram/g by the proposed method.     

Some nutritional properties of Prangos ferulacea (L.) Lindl and Rheum ribes L. stems growing wild in Turkey

In this study, some compositional properties and mineral contents of Prangos ferulacea and Rheum ribes stems growing wild in A?ri and Elazi? province in Turkey were investigated. Mineral contents were determined by inductively coupled plasma atomic emission spectrometry. Moisture, crude oil, crude fiber, crude ash, crude protein, water-soluble and alcohol-soluble extract, pH and acidity values of samples were determined. Both plants contained high amounts of crude ash, crude fiber and water-soluble extract. According to results, aluminum, calcium, iron, potassium, magnesium, sodium, phosphorus and zinc values were very high in both samples. The levels of calcium (4,248.58 mg/kg), potassium (60,613.03 mg/kg) and phosphorus (5,827.71 mg/kg) of P. ferulacea in this work were found to be higher than those of other location plants (R. ribes). Potassium ranged from 32,730.82 mg/kg R. ribes (Elazi? sample) to 60,613.03 mg/kg P. ferulacea (A?ri sample). The iron content ranged from 56.11 mg/kg R. ribes (A?ri sample) to 147.01 mg/kg R. ribes (Elazi? sample). This work contributed to the nutritional properties of these plant species, and the information may be useful for the evaluation of dietary information.     

匍扇藻多糖抗病毒活性的初步研究(英文)

目的:研究褐藻匍扇藻(Lobophora variegata)多糖的抗病毒活性。方法:匍扇藻多糖的粗提物经沸水提取和乙醇沉淀后获得,粗多糖经离子交换柱层析法分离以获取较纯的多糖片段。它们的抗病毒活性采用细胞病变效应减少法和空斑减少检测法检测。粗多糖的细胞毒性采用 MTT 法测定。结果:匍扇藻粗多糖具有显著的抗单纯疱疹病毒Ⅰ型和Ⅱ型的活性,它能抑制不同的单纯疱疹病毒毒株,包括标准株、阿昔洛韦抗性株和临床病毒株。通过空斑减少法测得它对阿昔洛韦抗性株和 HSV-Ⅱ型临床株的半数有效浓度(EC50)分别为 18.2 和 6.25 μg/ml。因为它的细胞毒性很低,因此具有较大的选择性系数。这种粗多糖有一定的抗呼吸道合胞病毒(RSV)活性,但对流感病毒没有抑制作用。该粗多糖经DEAE离子交换柱层析分离得到两个不同的多糖,它们也都显示出抗单纯疱疹病毒的活性。结论:匍扇藻含有具抗病毒活性的多糖并且对单纯疱疹病毒显示出较强的抑制作用。