高效液相色谱法测定马铃薯中α—茄碱含量

应用乙腈－磷酸二氢钾为流动相,在ＹＷＧ－Ｃ１８反相柱上采用外标法测定了马铃岭薯中不同部位上茄碱含量,方法快速,简便,重现性好。     

超高效液相色谱-串联质谱法测定马铃薯中α-茄碱和α-卡茄碱

目的 建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)测定马铃薯中α-茄碱和α-卡茄碱的含量。方法 样品经80%甲醇水(V:V, 含0.1%甲酸)溶液提取、稀释后在正离子模式下以电喷雾电离串联质谱进行测定, 外标法定量。结果 α-茄碱和α-卡茄碱在50~1000 μg/L范围内线性良好, 相关系数＞0.99, 方法检出限为20 μg/kg, 定量限为50 μg/kg。在3、5、10 mg/kg的添加水平下, α-茄碱和α-卡茄碱平均回收率在83.5%~96.0%之间, 相对标准偏差(relative standard deviation, RSD), (n=6)在2.97%~5.41%之间。结论 本方法快速、准确、灵敏, 可应用于马铃薯中α-茄碱和α-卡茄碱的同时检测。     

高效液相色谱串联质谱法检测马铃薯及马铃薯粉中α-茄碱和α-卡茄碱含量

建立了高效液相色谱-串联质谱同时测定马铃薯及马铃薯粉中α-茄碱与α-卡茄碱含量的方法。样品采用10%乙酸水溶液匀浆提取3 min,马铃薯粉提取液经Bond Elut C18 SPE柱净化后,采用C18色谱柱分离,液相色谱串联质谱仪检测。结果表明,α-茄碱和α-卡茄碱在0.01~1.00 μg/mL范围内线性关系良好,相关系数分别为0.9998和0.9997。马铃薯和马铃薯粉在低、中、高三个添加浓度范围内,回收率在90.0%~110%之间,相对标准偏差在1.6%~5.0%之间。马铃薯中α-茄碱和α-卡茄碱的定量限分别为0.80和0.42 μg/kg,马铃薯粉中α-茄碱和α-卡茄碱的定量限分别为25和14 μg/kg(S/N=10)。本方法简单快速,灵敏度高,重复性好,适用于马铃薯及马铃薯粉中的α-茄碱和α-卡茄碱检测。     

高效液相色谱法测定马铃薯中α─茄碱含量

应用乙腈-磷酸二氢钾（75:25,V／V）为流动相,在YWG－C18反相柱上采用外标法测定了马铃薯中不同部位上α─茄碱含量,方法快速、简便,重现性好。α─茄碱检测线性范围为0．1～1．0mg／ml,r＝0．9994,平均回收率为91．5％,变异系数为3．84％。     

超高效液相色谱-三重四级杆串联质谱法测定土豆中α-茄碱与α-卡茄碱含量

建立了超高效液相色谱-三重四级杆串联质谱法测定土豆以及薯片中α-茄碱与α-卡茄碱含量的方法。方法 样品经5%乙酸溶液提取,Waters Oasis C₁₈ SPE柱(600 cc)净化后,采用Waters BEH HILIC 色谱柱(100 mm×2.1 mm,1.7 μm)分离。流动相为乙腈∶水(含10 mmol/L乙酸铵)=88∶12(V/V),流速0.3 ml/min。以waters Xevo TQ-S三重四级杆质谱仪在电喷雾正离子化(ESI+)及MRM模式下定量。结果 α-茄碱在0.5～500 ng/ml范围内呈线性相关。方法精密度良好(RSD<10%,n=6),回收率>80%,α-茄碱和α-卡茄碱定量限分别为0.7和0.35 μg/kg(S/N=10)。结论 本方法快速简单,重现性好,灵敏度高,适合于土豆和薯片中α-茄碱和α-卡茄碱的检测。     

HPLC—ELSD法同时测定马铃薯中α-茄碱和α-卡茄碱含量

建立高效液相色谱—蒸发光散射检测(HPLC—ELSD)同时测定马铃薯中α-茄碱和α-卡茄碱的方法,并对不同样品含量进行测定。结果表明:当ELSD漂移管温度98℃,雾化管温度30℃,载气压力6.90kPa时,以0.1%三氟乙酸水—乙腈为流动相,经梯度洗脱程度,α-茄碱和α-卡茄碱可获得良好分离,色谱峰柱效高。样品用质量100倍的1%甲酸甲醇为提取溶剂在70℃下提取90min,提取液直接注入色谱仪进行检测。α-茄碱标准品在0.196~9.800μg线性关系良好(R2=0.999 5),平均回收率为99.4%,并以该标准曲线同时计算样品中的α-茄碱和α-卡茄碱的含量。马铃薯植物的不同部位均含有生物碱,α-茄碱的含量为0.13~1.59mg/g,α-卡茄碱的含量为0.39~8.28 mg/g;两种生物碱总量为0.52~9.37mg/g,同一部位中α-卡茄碱的含量为α-茄碱的1.2~7.6倍。     

马铃薯中α-茄碱提取工艺优化

为了获得马铃薯中α-茄碱的最佳提取工艺参数,对其提取温度、提取时间、超声波功率及料液比等参数进行研究,运用响应面Box Behnken中心组合试验设计对α-茄碱的提取工艺进行优化。结果表明:马铃薯中α-茄碱的最佳提取工艺参数为以体积比8:2的乙醇-乙酸混合溶液作提取溶剂,提取温度49℃,提取时间61 min,超声波功率152 W,料液比1:14(g/mL),该条件下α-茄碱提取量为7.715mg/g,RSD为1.74%(n=5),与理论预测值基本吻合,平均回收率为98.21%,RSD为1.33%(n=3),说明该方法的提取率和精密度高、稳定性好,合理可行。     

高效液相色谱-二极管阵列检测器法测定马铃薯及其制品中的α-茄碱和α-卡茄碱

该文建立了高效液相色谱-二极管阵列检测器法测定马铃薯及其制品中的α-茄碱和α-卡茄碱的方法。样品经酸化甲醇提取后,用无水硫酸钠和无水乙酸镁吸收多余的水分后离心,用高效液相色谱-二极管阵列检测器法进行检测。检测条件:用Hubble C18液相色谱柱(250 mm×4. 6 mm,5μm),以乙腈和0. 02 mol/L磷酸二氢钾溶液为流动相,流速为0. 2 mL/min,柱温为30℃,进样量为10μL,二级管阵列检测器检测范围190～810 nm,检测波长为195 nm。α-茄碱和α-卡茄碱在0. 2～200μg/mL时线性相关系数R2为0. 999 3～0. 999 8,方法检出限均为0. 5 mg/kg,定量限均为1. 7 mg/kg,4、6、10μg/mL三个浓度加标水平的回收率为98%～107%,相对标准偏差为0. 05%～0. 44%。该方法前处理简单、灵敏度高、重现性和回收率好,有良好的精密度、准确度,可用于马铃薯及其制品中α-茄碱和α-卡茄碱分析检测。     

高效液相色谱-串联质谱法测定茄科蔬菜及其制品中α-茄碱和α-卡茄碱的含量

目的建立通过式固相萃取-高效液相色谱-串联质谱法同时测定茄科蔬菜及其制品中α-茄碱和α-卡茄碱含量的分析方法。方法样品采用1%甲酸水溶液:乙腈=1:1 (V:V)涡旋提取, Oasis? PRiME HLB固相萃取(solid phase extraction, SPE)柱净化,经过色谱柱BEH Amide (2.1 mm×100 mm, 1.7μm)分离,以2 mmol/L乙酸铵的0.1%甲酸水溶液(A):2mmol/L乙酸铵的乙腈溶液(B)为流动相进行梯度洗脱,柱温40℃,流速0.4 mL/min,多反应模式监测,基质匹配标准曲线外标法定量。结果在1~500 ng/mL范围内,α-茄碱和α-卡茄碱与峰面积线性关系良好(相关系数r2>0.998)。在低、中、高3个水平添加下,α-茄碱回收率为91.3%~104.6%,α-卡茄碱回收率为90.3%~108.4%,相对标准偏差不超过5.5%(n=6)。结论该方法快速简便、准确度好、灵敏度高,适用于大批量茄科蔬菜及其制品中α-茄碱和α-卡茄碱的快速测定。     

超高液相色谱串联质谱法检测土豆及土豆制品中α-茄碱

目的建立超高效液相色谱串联质谱法检测土豆及其制品中α-茄碱的分析方法。方法通过优化提取液,土豆样品经1%甲酸-甲醇(1:1,V:V)超声提取,采用BEH C_(18)色谱柱(2.1 mm×50 mm,1.7μm)分离,梯度洗脱,采用超高效液相色谱串联质谱法,在多反应监测模式进行定性和定量分析,而土豆淀粉用MCX固相萃取柱进行净化,液相色谱串联质谱法测定。结果土豆样品中回收率为75%~115%,相对标准偏差为5.0%~8.6%,土豆淀粉的回收率范围为67%~100%,相对标准偏差为3.4%~11.3%,方法的检出限和定量限分别为0.5 mg/kg和1.0 mg/kg。结论该方法适合于土豆及其制品中α-茄碱的分析。     

海藻酸钠提取的新研究

海藻酸钠作为一种天然高分子物质已被广泛应用。本实验以海带为原料,用离子交换法提取海藻酸钠,其产品粘度为2.84Pa·s,提取率高达42.6%,并大幅度节省了原料与动力,降低了生产成本。除此之外,通过实验也找到了Na2CO3浓度、消化温度、消化时间对海藻酸钠提取率的影响关系。      

A simple and quick gas chromatographic method for the determination of propham and chlorpropham in potatoes.

This study describes a gas chromatographic method for the quantitative determination of residual propham and chlorpropham in potatoes. Both herbicides are extracted from the foodstuff with methylene chloride. After centrifugation and concentration, propham and chlorpropham are quantitatively determined by gas chromatography thermionic detection using a fused silica capillary column CP Sil 5CB. 2-Chloraniline is used as internal standard. Recoveries of 100 +/- 15% and 99 +/- 10% have been obtained for propham and chlorpropham in blank samples spiked at the level of 0.5, 1.0 and 5.0 mg/kg. The absolute detection limit for both compounds is 1 ng corresponding to 0.1 mg/kg. Of the 161 samples of fresh potatoes analysed using this method, 136 contained residues of these herbicides and 18 of them (11%) exceeded the maximum tolerated value of 5 mg/kg.     

一种快速测定蛋白质含量的新方法

研究了用电位滴定法测定蛋白质含量的一种新方法。与凯氏法相比,该方法具有操作简便、结果准确、快速、节能等特点。经ｔ检验法进行显著性检验,该方法与凯氏法无显著性差异。适用于酿酒及食品行业中蛋白质含量的分析。     

有效去除马铃薯中龙葵素方法的探究

目的探究一种日常生活中简单有效去除马铃薯中龙葵素的方法。方法对马铃薯进行分组贮藏实验,通过不同预处理方法(如去芽孔径大小、不同加工形状、不同浓度食醋水溶液或柠檬酸水溶液浸泡等)处理后采用液相色谱串联质谱法测定龙葵素含量,研究龙葵素含量的变化情况。结果对于轻微发绿或发芽马铃薯,可以进行削皮、去芽处理后,进行水浸、食醋水溶液浸、柠檬酸水溶液浸处理5～15 min,均可降低马铃薯中约70%～80%龙葵素。结论此方法实用性和可操作性强,可有效预防家庭、餐馆以及食堂等龙葵素中毒事件发生,对保障人民食品安全具有重要意义。     

A new enzymatic method for determination of sulphite in food

A novel enzymatic method for determining sulphite is described. Using the enzyme sulphite oxidase (EC 1.8.3.1) isolated from chicken liver, sulphite is oxidised to sulphate and hydrogen peroxide is formed. This is allowed to react with reduced nicotinamide-adenine dinucleotide (NADH) in the presence of NADH-peroxidase from microorganisms (EC 1.11.1.1). The decrease of NADH, which is proportional to the concentration of sulphite, is measured photometrically.In spite of doubts about determining sulphite quantitatively according to this principle, the reaction conditions could be optimised: sulphite is oxidised in triethanolamine buffer (TEA) at pH8·0 with 40 mU/ml sulphite oxidase and 47 mU/ml NADH-peroxidase quantitatively within a period of 20 min. The precision of measurement is very high in the range 13–205 μmol sulphite/litre test solution. The coefficient of variation is found to be CV = 0·67% in a solution of 67 μmol SO₂/litre.The accuracy of the enzymatic measurements in pure aqueous sulphite solutions is confirmed by comparison with chemical determination. The correlation with the iodimetric method is R = 0.995.High specificity for sulphite is found when applying the enzymatic test described here. Carbonyl/sulphite addition compounds (e.g. those occurring in wine) are converted to sulphate and the free carbonyl compound. The majority of sulphur-containing compounds do not react in the test. Only glycosides of isothiocyanates (e.g. in mustard) are oxidised like sulphite, though more slowly.The majority of substances occurring in food do not interfere significantly with the test. Ascorbic acid influences the determination if it is present in high concentrations. Therefore, it should be removed from the sample before measuring sulphite.The method has been proven in use for a large number of foodstuffs. By using the method described here, sulphite can be determined in food rapidly and with high reliability.     

A new solid phase extraction clean-up method for the determination of 12 type A and B trichothecenes in cereals and cereal-based food by LC-MS/MS

A new reliable and cost-efficient solid phase extraction-based clean-up method for the determination of 12 type A and B trichothecenes [deoxynivalenol (DON), nivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, fusarenon-X, T-2 toxin, HT-2 toxin, neosolaniol, monoacetoxy-scirpenol, diacetoxyscirpenol, T-2 triol and T-2 tetraol] in cereals and cereal-based food is presented. Furthermore, the suitability for the simultaneous determination of zearalenone is examined. Toxins were extracted from cereal samples using ACN/water (80/20, v/v), purified by means of a new Bond Elut Mycotoxin column and analyzed via liquid chromatography-electrospray ionization tandem mass spectrometry. Limits of detection were calculated for the matrix wheat and ranged from 0.3 to 5 ng/g, depending on the toxin. Average recovery rates for the tested compounds in seven cereal-based matrices have been determined ranging from 65 to 104%. The relative standard deviations of the complete method ranged from 2.67 (DON, wheat) to 20.0% (T-2 toxin, oats).     

索氏法提取和测定油茶籽油的条件优化

除富含不饱和脂肪酸的茶油外,油茶中还含有茶多糖、茶皂素、茶多酚等多种生物活性成分。以油茶生物活性物质的提取和制备为前提,本研究以简单、有效地提取茶油为目标,以油茶籽含油率为指标,在索氏抽提法单因素实验基础上,选择提取时间、提取温度、提取溶剂种类和单次样品重量为影响因素进行正交优化实验。结果表明,油茶索氏提取的最佳条件为:提取时间6 h、提取温度80℃、有机溶剂丙酮、单次样品重量4 g。该条件下茶籽含油率达43.24%±0.53%。该条件下测得4种油茶整籽和种仁的含油率从高到低依次为广宁红花油茶、普通油茶、小果油茶和高州油茶;广宁红花油茶的整籽和种仁含油率均最高,且饼粕含油率最低,分别为49.7%、67.5%和6.1%。优化后的油茶索氏抽提条件,适用于茶油成分的有效提取和针对油茶籽油的定量分析。      

A new enzymatic method for the extraction of precarthamine from dyer's saffron florets

Precarthamine was extractable at a high yield from the floret paste of dyer's saffron, when pretreated with glucosidase in water. The hydrolysate extraction conditions, recovery rate, and identification were studied in order to establish a new enzymatic method for the preparation of precarthamine. The results are evaluated by comparison with the old procedures.

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Eine neue enzymatische Methode zur Extraktion von Precarthamin aus Safranblütenpaste

Zusammenfassung Precarthamin wurde in großer Menge aus Safranblütenpaste extrahiert, die mit Glucosidase in Wasser vorbehandelt wurde. Die Hydrolysebedingungen, die Ausbeute und die Identifizierung wurden studiert, um eine neue enzymatische Methode für die Herstellung von Precarthamin zu entwickeln. Die Resultate wurden mit der alten Arbeitsweise verglichen.