分散固相萃取—高效液相色谱检测花生中咪唑乙烟酸残留

确立了花生籽粒样品中咪唑乙烟酸残留的甲醇涡旋提取、PSA净化的分散固相萃取样品前处理程序,建立并优化了高效液相色谱样品检测方法.结果显示:在确定的色谱条件下,咪唑乙烟酸在0.05~10.0 mg/L质量浓度范围内与对应的色谱峰面积线性响应良好,其回归方程为y=4.003 8x-0.275 6(R2=0.999 5),方法的检出限(LOD)为0.016 mg/L.咪唑乙烟酸0.05、0.10和0.50 mg/kg 3个添加水平的平均回收率均在85%以上,RSD均小于10%,方法的检测限(LOQ)为0.036 mg/kg.表明所建立残留样品前处理方法和高效液相色谱检测方法简便、经济、快速、灵敏,适于花生中咪唑乙烟酸残留量的检测.     

高效液相色谱法测定化妆品中四种雌激素

目的:建立反相高效液相色谱法同时测定化妆品中的4种雌激素(雌酮、雌三醇、炔雌醇、己烯雌酚)的方法。方法:色谱柱Inertsil ODS-C18(4.6 mm×250 mm,5μm),流动相为甲醇-水(体积比为60:40),流速1mL/min,检测波长279nm,柱温:25℃。结果:4种雌激素成分在0.05～500μg/mL浓度范围内与其对应分峰面积线性关系良好。样品的平均加标回收率为97.3%～110.6%,RSD为2.9%～4.0%,化妆品中四种雌激素的检出限为0.02～0.03mg/kg。该方法操作简便、灵敏度高,能够同时检测化妆品中4种雌性激素的含量。     

分散固相萃取--高效液相色谱检测花生中咪唑乙烟酸残留

确立了花生籽粒样品中咪唑乙烟酸残留的甲醇涡旋提取、PSA净化的分散固相萃取样品前处理程序,建立并优化了高效液相色谱样品检测方法.结果显示：在确定的色谱条件下,咪唑乙烟酸在0.05~10.0 mg/L质量浓度范围内与对应的色谱峰面积线性响应良好,其回归方程为y=4.0038x-0.2756（R2=0.9995）,方法的检出限（LOD）为0.016 mg/L.咪唑乙烟酸0.05、0.10和0.50 mg/kg 3个添加水平的平均回收率均在85%以上,RSD均小于10%,方法的检测限（LOQ）为0.036 mg/kg.表明所建立残留样品前处理方法和高效液相色谱检测方法简便、经济、快速、灵敏,适于花生中咪唑乙烟酸残留量的检测.     

高效液相色谱测定海虾中呋喃唑酮残留量

目的:探讨海虾样品中呋喃唑酮残留量的测定方法.方法:采用高效液相色谱(HPLC)法,样品用二氯甲烷提取、正己烷净化、外标法定量,检测海虾中呋喃唑酮残留量.结果:本方法工作曲线线性范围为0.01~1.00 ug/mL,R=0.999 1.检测下限为1.0 ug/kg,回收率89.7%~94.7%,相对标准偏差(RSD)3.1%~3.5%.结论:本测定方法准确,灵敏,达到了实验方法的要求.     

高效液相色谱法测定烧鸡中苯并[α]芘的残留

本文建立了高效液相色谱法检测烧鸡表皮中苯并[α]芘含量的方法.样品经过超声提取5min,环己烷和二甲基亚砜作为提取溶剂,最后用甲醇溶解.在确定色谱条件下检测,回收率和精密度都比较高,最低检测限为0.1μg/kg.结果表明,烧鸡在油炸上色过程中,随着油炸时间的延长,苯并[α]芘的含量是逐步上升的.     

高效液相色谱法测定益眠胶囊中阿魏酸的含量

目的:建立用高效液相色谱法测定益眠胶囊中阿魏酸的含量的方法。方法:LichrospherC18色谱柱(150mm×4.6mm,5μm);流动相甲醇-1%冰醋酸(25∶75);柱温:室温;流速1.0ml/分钟;检测波长:320nm。结果:该方法回收率为98.93%RSD 2.60%。结论:该方法简便、快速、灵敏度高,可用于该产品的质量控制。     

高效液相色谱法快速测定饮料中苯甲酸的方法研究

采用反相高效液相色谱法(HPLC)测定了饮料中的苯甲酸含量,建立了快速测定苯甲酸的方法.色谱条件为:流动相体系为甲醇与乙酸铵溶液(0.02mol/L),体积比为5:95,流速为1.0 mL/min,紫外检测波长为230 n m,柱温为25℃,进样体积为10μL.采用外标法定量,在5～100μg/ml范围内,回归方程相关系数为0.99999,检出限为0.38μg/mL.饮料中苯甲酸的加标回收率在97.80%～102.41%.按上述色谱条件平行测定样品5次,峰面积相对标准偏差(RSD)为0.1357%.说明方法的精密度高,重现性良好.     

LC/MS法测定纺织品中残留烷基酚和烷基酚聚氧乙烯醚

以甲醇为提取溶剂,采用微波辅助萃取法提取纺织品中残留的辛基酚、壬基酚、辛基酚聚氧乙烯醚、壬基酚聚氧乙烯醚,用高效液相色谱-质谱法进行测定,并对前处理条件进行了优化。该方法的检测限(S/N=5)为0.010-0.025μg/mL,回收率为93.19%-103.97%,精密度实验的相对标准偏差为1.03%-4.96%。     

UPLC-MS/MS法测定酒中邻苯二甲酸酯

建立了酒中8种邻苯二甲酸酯的超高效液相色谱-串联质谱联用仪检测方法。白酒、葡萄酒、黄酒等经前处理后,使用Waters ACQUITY UPLC仪和Waters Quattro Premier三级四极杆质谱仪,采用超高效液相苯基反相色谱柱分离,甲醇-水流动相流速0.2 mL/min,进样量2.0μL,电喷雾离子化串联质谱分析检测。该方法专一性强,检测耗时短,定量准确。检测酒中邻苯二甲酸酯的线性范围0.5¹0.0mg/L,检出限0.05 mg/L,回收率86.4%10.0mg/L,检出限0.05 mg/L,回收率86.4%¹04.7%,相对标准偏差小于8.7%。     

高效液相色谱法测定蘑菇中麦角甾醇的含量

建立了高效液相色谱测定蘑菇中麦角甾醇含量的方法.采用甲醇为提取液,超声提取样品中的麦角甾醇,色谱条件为Kromasil ODS C 18色谱柱(250 mm×4.6 mm,5μm);流速1.0 mL/min;检测波长281 nm;以甲醇为流动相.结果表明,麦角甾醇在0.04~0.5 mg线性良好,R=0.9996,样品加标平均回收率为99.6%,RSD=1.03%,共测定11种蘑菇中麦角甾醇含量,香菇含量最高为482.5 mg/100g.该方法简便、精密度良好,可用于蘑菇中麦角甾醇的含量测定.     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.