超高效液相色谱串联质谱法测定腐竹中乌洛托品的含量

建立用超高效液相色谱-串联质谱法(UPLC-MS/MS)测定腐竹中乌洛托品含量的方法。用乙腈提取腐竹中的乌洛托品,经固相萃取柱PXA净化,用UPLC-MS/MS分析,采用多反应监测模式,外标法定量。采用ACQUITY UPLC BEH HILIC色谱柱,以乙酸铵和乙腈为流动相,进行梯度洗脱。结果表明:该方法标准曲线良好,线性范围为1~20μg/L,最低检出限为1μg/L,三个水平添加浓度的平均回收率范围为81.67%~101.67%。本方法操作简单快捷,方法准确度和稳定性好。     

ELISA和UPLC-MS/MS联合检测粮食中玉米赤霉烯酮残留

建立酶联免疫吸附分析(enzyme-linked immunosorbent assay,ELISA)和超高效液相色谱-串联质谱(ultra performance liquid chromatograph-tandem mass spectrometry,UPLC-MS/MS)联合测定粮食中玉米赤霉烯酮的快速检测方法。样品经乙腈-水-乙酸(70∶29∶1,V/V)溶液提取,采用ELISA筛选出阳性样品后利用UPLC-MS/MS进行验证。实验探讨了ELISA和UPLC-MS/MS联合检测法的有效性和测定中存在的问题及其矫正方法,并且研究了UPLC-MS/MS中样品净化与未净化的回收率。结果表明,本实验建立的ELISA和UPLC-MS/MS联合检测方法快速、高效,适用于大批量粮食样品中玉米赤霉烯酮残留量的快速评估。     

超高效液相色谱-串联质谱法测定鱼肉组织中9种黄色染色剂

目的 建立超高效液相色谱-串联质谱法(UPLC-MS/MS)正负离子切换模式同时测定鱼肉组织中9种黄色染色剂的分析方法.方法 试样经氨水甲醇溶液和甲酸水甲醇溶液提取,上清液旋蒸复溶,正己烷除脂,离心后上清液用UPLC-MS/MS法测定,外标法定量.结果 柠檬黄、日落黄、喹啉黄在2～30 μg/kg,酸性橙Ⅱ、碱性橙2、...     

高效液相色谱-二极管阵列检测法和超高效液相色谱-串联质谱法检测鱼腥藻毒素的比较研究

目的比较高效液相色谱-二极管阵列检测法(high performance liquid chromatography-photodiode array detector, HPLC-PDA)和超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)对鱼腥藻毒素的检测。方法样品经酸性甲醇提取后使用超滤管去除杂质,采用HPLC-PDA和UPLC-MS/MS检测样品中鱼腥藻毒素AnTX-a及HAnTX-a的含量。结果 2种方法均能有效分离分析AnTX-a及HAnTX-a,且均能排除样品中L-苯丙氨酸的干扰。HPLC-PDA检测法对AnTX-a及HAnTX-a的检测限分别为0.052和0.070μg/mL;UPLC-MS/MS检测法对AnTX-a及HAnTX-a的检测限均为0.010 ng/mL。结论 2种方法准确、灵敏度高, UPLC-MS/MS较HPLC-PDA检测法具有高灵敏度、高检测效率的优势,但HPLC-PDA检测法更具普遍适用性。     

UPLC-MS/MS测定蔬菜中氨基甲酸酯类农药

建立超高效液相色谱-串联质谱(UPLC-MS/MS)测定蔬菜中氨基甲酸酯类农药的方法。用乙腈提取蔬菜中的氨基甲酸酯类农药,经QuEChERS净化后UPLC-MS/MS定量分析。实验浓度范围内线性关系良好,方法加标回收率在82.2%~104.1%,精密度(RSD)为1.9%~4.0%,检出限为0.2~1.5μg/kg。UPLC-MS/MS法测定蔬菜中氨基甲酸酯类农药有较好的回收率、重现性和较低的检出限,能满足大批量样品氨基甲酸酯类农药的快速检测需求。     

UPLC-MS/MS法与分光光度法测定乳及乳制品中左旋肉碱的比较

文中建立了超高效液相色谱-质谱联用仪(UPLC-MS/MS)和分光光度计测定乳及乳制品中L-肉碱的方法。超高压液相色谱-质谱联用法采用C8(3.5μm,50 mm×2.1 mm)色谱柱,0.1%七氟丁酸/水溶液和甲醇作为流动相分离样品,L-肉碱-(甲基-d3)内标物质用以消除信号抑制和基质干扰,质谱采用ESI+电离模式、多离子反应监测(MRM)方式进行检测。分光光度法采用高氯酸沉淀蛋白质,碱皂化使溶液中结合态的左旋肉碱游离出来,通过酶促反应,使用分光光度计间接测定左旋肉碱。结果表明:分光光度法的检出限为2.0 mg/100 g,回收率在96.2%¹04.7%,相对标准偏差RSD在1.34%104.7%,相对标准偏差RSD在1.34%³.69%。UPLC-MS/MS法的检出限为2 ng/100 g,回收率在97.8%3.69%。UPLC-MS/MS法的检出限为2 ng/100 g,回收率在97.8%¹09%,相对标准偏差RSD为1.77%109%,相对标准偏差RSD为1.77%⁵.65%。以上2种方法均适用于乳及乳制品中L-肉碱的检测,且测定结果无显著性差异。UPLC-MS/MS法具有操作简便、快速、高效、可控性强等特点,更适用于大量样品的集中快速检测。     

HPLC-PAD外标法及UPLC-MS/MS内标法测定乳及乳制品中三聚氰胺的含量

分别建立高效液相色谱-二极管阵列法(HPLC-PAD)、超高压液相色谱-串联质谱法(UPLC-MS/MS)测定乳及乳制品中三聚氰胺含量的方法。利用HPLC-PAD外标法进行样品中三聚氰胺的初筛,利用UPLC-MS/MS法进行确证,以13C315N3-三聚氰胺为同位素内标定量。乳制品经乙腈、乙酸锌、盐酸溶液提取,质谱检测时,样品再经MCX固相萃取柱富集净化。HPLC-PAD法的定量限为4mg/kg,UPLC-MS/MS的定量限为0.05mg/kg;HPLC-PAD的添加回收率为95.7%～102.3%,UPLC-MS/MS的添加回收率为91.3%～95.7%(基质匹配曲线校正),两种方法的相对标准偏差(RSD)分别为1.98%～4.51%,1.60%～3.27%。     

UPLC-MS/MS法和HPLC法测定苹果中氨基甲酸酯类农药的对比

目的:基于检出限、精密度、准确度、加标回收率等指标,考查超高效液相色谱-串联质谱法(UPLC-MS/MS)和高效液相色谱法(HPLC)测定苹果中氨基甲酸酯类农药的一致性及适用性。方法:分别采用UPLC-MS/MS法和HPLC法测定苹果中的氨基甲酸酯类农药。UPLC-MS/MS法:苹果样品中的氨基甲酸酯类农药经乙腈提取,QuEChERS净化后,UPLC-MS/MS进行分离并定量分析;HPLC法:苹果样品中的氨基甲酸酯类农药经乙腈超声提取后,CARB/NH_2固相萃取柱净化,高效液相色谱-柱后衍生法进行分离并定量分析。结果:HPLC法加标回收率在79%～83%,日内精密度(RSD%)为1.9%～5.3%,方法检出限为2.0～5.0 μg/kg;UPLC-MS/MS法加标回收率在83.2%～103.1%,日内精密度(RSD%)为0.9%～3.1%,方法检出限为0.5～1.5 μg/kg。结论:相较于HPLC法,UPLC-MS/MS 法保留时间更短、检出限更低,且操作简便、重现性好,可作为苹果中氨基甲酸酯类农药残留检测的推荐方法。     

UPLC-MS/MS与HPLC测定茶叶中10种氨基甲酸酯类农药残留的比较

比较了超高效液相色谱-串联质谱(UPLC-MS/MS)与高效液相色谱(HPLC)法测定茶叶中10种氨基甲酸酯类农药残留的分析方法。样品经乙腈提取,氨基固相萃取柱净化,HPLC和UPLC-MS/MS测定。结果表明,在相同的前处理条件下,两种方法均具有较好的准确度和精密度,UPLC-MS/MS法在0.01~0.1mg/kg添加水平下回收率为75.2%~115.6%,相对标准偏差(RSD)为4.4%~16.7%。HPLC法在0.05~1.0mg/kg添加水平下回收率为82.7%~120.7%,相对标准偏差(RSD)为0.8%~12.9%。UPLC-MS/MS法相对于HPLC法有更高的灵敏度,10种氨基甲酸酯类农药在UPLC-MS/MS上检出限为0.02~0.3μg/kg,HPLC法检出限为3~7.5μg/kg;其高灵敏度和选择性,使其更适于多农药残留同时检测和微量残留检测。     

UPLC-MS/MS定性测定紫薯花青苷方法研究

目的:以紫薯1号和农林47为实验材料,建立超高效液相色谱-三重四级杆串联质谱(UPLC-MS/MS)法,研究紫薯提取液中花青苷定性的分析方法.方法:UPLC-MS/MS法,ACQUITY UPLC BEH C18(2.1mm×50mm,1.7 μm);柱温:40℃;流速:0.3mL/min;以6％甲酸水溶液和乙腈为流动相,采用电喷雾(ESI)正离子模式,用MRM模式监测.结果:紫薯1号和农林47提取液中花青苷组分分别为矢车菊素-3-葡萄糖苷和芍药素-3-葡萄糖苷.结论:该方法具有准确度高,重复性好、简单、快速等显著优点,可用于紫薯及其它作物中花青苷组分的测定.     

国际绿趋势 绿家居 绿家具—自然 健康 环保 单纯 可续 经济

“绿生活”就是健康可持续的友好生活态度及方式。在人类文明高度发展的今天,绿色的生活方式正在变得越来越随处可见,环保生活的标地也不仅仅是糙米和草鞋,而是在每一处生活必需品都不断发展环保的创意,通过可以循环再造的尖端物科和天然材料共同营造回归自然的健康、简约之美。     

Mineral contents of some southern Italian wines. II. Determination of Li, Na, Mg, K, Ca, Co, As, Rb, Sr, Ag, Sb, Ba

Following our study of the mineral contents of some Southern Italian wines, this work reports on the detection of 12 elemental components. The elements were determined using ICP-AES, flame atomic emission or absorption spectroscopy. The values determined for Li, Na, Mg, K, Ca, Rb, Sr and Ba were within the usual ranges for wines (average values for these elements were: 0.010, 26.2; 94.4; 888; 94.0; 3.30, 0.82 and 0.11 mg/l respectively). All the wines contained low levels of As, the concentrations of which were always under 0.20 mg/l, the maximum level permitted by E.E.C. standards. The measuring of Co, Ag, and Sb led us to ascertain, in all the wines, concentrations lower than 0.01 mg/l for Co and Ag and below the instrumental detection level for Sb (0.06 mg/l). In a previous study wines from D.O.C. areas of Southern Italy were analysed by the technique of inductively coupled plasma atomic emission spectroscopy (ICP-AES), for 14 minerals. This paper deals with further investigation of the mineral composition of the same wines for different metal constituents, analysed by ICP-AES, flame atomic emission, or atomic-absorption spectroscopy (two techniques). The first technique was applied to the detection of Co, As, Sr, Ag, Sb, and Ba. The alkaline metals Li, Na, K, and Rb were determined by flame atomic emission, a technique which possesses better detection limits for these elements. For Mg and Ca the atomic absorption methods were applied.     

风干肠贮藏过程中挥发性风味物质的变化及异味物质分析

利用动态顶空制样-热脱附-气相色谱-嗅闻-质谱联用技术,结合气味活度值(odor activity value,OAV)以及感官评价,对不同贮藏时间(0、7、14、21、35、49、77 d)的风干肠挥发性风味物质进行检测,分析贮藏过程中各类挥发性物质变化情况,并对造成异味的主要物质进行鉴别。结果表明:不同贮藏时间的样品中,分别检出挥发性风味物质59、56、63、58、73、68、71种,主要为酯类物质;随着贮藏时间的延长,风干肠样品色泽变黑,失去光泽,异味逐渐增加,可接受度降低,其中有21、21、17种风味活性物质分别与感官评价中色泽、风味、可接受度评分显著相关;经过OAV分析以及气相色谱-嗅闻鉴定,辛酸乙酯、1-辛烯-3-醇、正己醛、庚醛、正辛醛、壬醛、反,反-2,4-癸二烯醛可能是造成风干肠异味的主要物质。     

1997 UK Total Diet Study dietary exposures to aluminium, arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, tin and zinc

Concentrations of aluminium, arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, tin and zinc were determined in samples from the 1997 UK Total Diet Study and used to estimate dietary exposures of the general UK population. Population average dietary exposures to aluminium (3.4mg/day), arsenic (0.065mg/day), cadmium (0.012mg/day), chromium (0.10mg/day), copper (1.2mg/day), mercury (0.003mg/day), nickel (0.13mg/day), tin (1.8mg/ day) and zinc (8.4mg/day) are similar to those from previous UK Total Diet Studies and are below the appropriate PTWIs, PMTDIs and TDIs. Dietary exposure of the UK population (0.026 mg/day) to lead is falling as a result of measures taken to reduce lead contamination of the environment and food and is well below the PTWI. There has been little change in UK estimates of selenium exposure since the 1994 Total Diet Study but current estimates (0.039mg/day) are lower than those derived from earlier Total Diet Studies.     

卷烟中锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量分析

采用微波消解-电感耦合等离子体质谱法测定了41个牌号烤烟型卷烟和雪茄烟样品烟丝中的锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量,并按照类型和价位对卷烟中这10种有害元素含量进行了统计分析。结果发现:①卷烟中锂和铜的含量较高,铊的含量很低,铬、镍、镉、铅、砷、硒和钼7种元素的平均含量为0.55～4.42μg/g;②雪茄烟中铬、镍、砷、钼、镉、铊和铅的含量一般高于烤烟型卷烟,而硒元素的含量则相反,但差别较小;烤烟型卷烟中锂和铜的含量与雪茄烟没有显著差异;③高档卷烟中的锂、镍、镉、铊和铬含量较低,而砷、铅的含量较高;不同价位卷烟的铜、硒和钼含量差异不显著。     

基于高压结合酶法制备的低敏虾制品体内体外致敏性检测的差异性分析

采用高压结合酶法处理凡纳滨对虾的虾蛋白、虾仁泥(虾肉)和虾仁,获得3种低敏虾制品;采用酶联免疫吸附法检测3种虾制品的过敏原性,采用全身性过敏反应(过敏性休克模型)及致敏离体回肠平滑肌收缩实验(Schultz-Dale反应)检测3种低敏虾制品的致敏性,以分析体内与体外方法检测虾制品致敏性的差异性。结果显示:处理前的3种原料过敏原性极高。经高压结合酶法处理的虾蛋白、虾肉和虾仁的过敏原性分别消减97.0%、94.1%和94.5%。而在动物实验中(以磷酸缓冲盐溶液为阴性对照,未处理虾蛋白为阳性对照,以豚鼠为受试对象),未处理虾蛋白组的过敏反应发生率与死亡率均为100%,3种低敏虾制品的过敏反应发生率也为100%,死亡率分别为16.7%(虾蛋白产物)、50%(虾肉产物)和83.3%(虾仁产物)。致敏的离体回肠受到3种低敏虾制品攻击后,收缩力也明显增强,分别达到376.9%、766.2%和1 004.4%。上述结果表明,对高压结合酶法制备的低敏虾制品过敏原性的检测,体外检测与体内检测存在一定的差异性。     

Starch noodles: History,classification, materials,processing, structure,nutrition, quality evaluating and improving

Starch noodles, produced from purified starch of various plant sources, are a major category of Asian noodles. This review summarizes the current knowledge on: (1) Definition, naming, history and categories of starch noodles. (2) The morphological, physico-chemical, thermal, rheological characteristics and molecular structure of materials including mung bean starch, pea starch, sweet potato starch, potato starch and corn starch. (3) Processing technology of starch noodles including dropping, extruding and cutting. (4) Structure of starch noodles: it is composed of hydrolysis-resistant crystalline zone, network-like framework and filler mass. (5) Nutrition of starch noodles: it could be evaluated by the digestibility of starch, hydrolysis properties of gelatinized and retrograded starches, hydrolysis property of starch noodles. (6) Quality evaluating of starch noodles: it includes sensory, cooking and texture property. Correlation between the physical properties of starch, processing variables and the sensory, cooking and texture property of starch noodles are summarized. (7) Quality improving for non-mung bean starch noodles: (a) using other materials such as red bean starch, pigeonpea starch, potato starch, sweet potato starch, corn starch, to substitute totally or partly mung bean starch; (b) adding chemically modified starch; (c) adding physically modified starch; (d) biologically treating starch; (e) using additives such as chitosan, polysaccharide gums.