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1.
采用液相色谱-质谱联用技术,建立测定不同状态的蜂王浆中4种四环素族抗生素残留量的测定方法.蜂王浆样品试样中四环素族药物残留量用0.1 mol/L Na2EDTA-Mcllvaine缓冲溶液提取,经过滤和离心后,上清液用PLS固相萃取柱净化,液相色谱串联质谱仪测定,外标峰面积法定量.4种药物基本实现分离以及定性定量.蜂王浆中四环素药物残留的测定低限(LOQ)为10 μg/kg,线性范围为10~50ng/mL.回收率均在88.0%~102.0%之间,相对标准偏差(RSD)不大于20%.土霉素、四环素,金霉素、强力霉素的检测限为10μg/kg.该方法灵敏、可靠,可用于不同状态蜂王浆中4种四环素类抗生素的同时检测. 相似文献
2.
为测定上海青中9种抗生素(氯霉素类、喹诺酮类),建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)的检测方法。将采集的样品经乙腈浸没超声提取,加入无水Na2SO4,NaCl盐析除去水分,使用C18及PSA吸附剂净化杂质,质量分数为0.1%的甲酸 乙腈溶液定容;然后在正负离子模式下,流动相分别为质量分数0.1%甲酸水-乙腈(ESI+)和超纯水-乙腈(ESI-),按设定梯度洗脱,并多反应监测测定9种抗生素。结果表明,氯霉素类抗生素在 0.5~10 μg/L 范围内线性关系良好,喹诺酮类抗生素在 5~100 μg/L 范围内线性关系良好,相关系数r均大于0.99,检出限为0.02~2.49 μg/kg,定量限为0.06~9.95 μg/kg。9种抗生素在10,50和100 μg/kg 3个添加水平下的回收率为76.6%~123.7%,相对标准偏差(n=7)为0.3%~11.0%。可见,该方法灵敏度高、净化效果好,适用于多种抗生素在上海青中的同时测定。 相似文献
3.
液-质联用测定鱼体内甲基磺草酮的残留量 总被引:1,自引:0,他引:1
为了检测鱼体内甲基磺草酮的残留量,建立液相色谱串联质谱的方法测定甲基磺草酮。结果表明:在0.5~100μg/L浓度范围内,线性相关系数(r)为0.998 6。当添加质量分数为0.1~10μg/g时,甲基磺草酮在鱼体内的平均回收率为80.0%~99.3%,RSD为3.4%~8.4%。该方法的最小检出量为5.0×10-12g,鱼体内的最低检测质量分数(LOQ)为0.1μg/g。该方法操作简单可靠,准确度、精密度及其灵敏度均满足农药残留分析的要求,可用于鱼体内甲基磺草酮残留量的测定。 相似文献
4.
超高效液相色谱-串联质谱法检测禽畜肉中的氯霉素残留 总被引:4,自引:0,他引:4
研究了一种针对禽畜肉中氯霉素残留量的超高效液相色谱-串联质谱联用分析方法.本方法采用乙酸乙酯萃取禽畜肉中的氯霉素,提取液氮吹至干后用超纯水溶解样品残渣,然后用HLB小柱进行固相萃取,经过净化的样品通过超高效液相色谱进行分离,然后用电喷雾质谱负离子多反应监测模式对氯霉素进行检测.该方法的检出限为0.0025μg/kg,添加水平为0.1~5.0μg/kg时,加标回收率为75.8%~82.5%,相对标准偏差小于10%.该方法具有灵敏度高、选择性好、分析时间短等优点. 相似文献
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6.
建立了用毛细管柱气相色谱法测定绿茶中八氯二丙醚(S-421)残留量的方法。绿茶样品用正己烷提取,经硅藻土545(1 g)-浓硫酸(0.4 mL)净化,以正己烷洗脱;经毛细管气相色谱柱DB-1701(30 m×0.32 mm×0.25μm)分离,电子捕获检测器测定,外标法定量。试验结果表明:八氯二丙醚在0.010~0.100 mg/L质量浓度范围内线性关系良好(r=0.999 4),方法的定量限为0.01 mg/kg;添标水平为0.02,0.04,0.08 mg/kg时,平均回收率在92.9%~97.2%之间,相对标准偏差不大于3.6%。该法操作简单,实验结果准确可靠,可用于绿茶中八氯二丙醚残留量的测定。 相似文献
7.
《广西民族大学学报》2019,(4)
研究以超高效液相色谱—三重四级杆串联质谱联用技术(UPLC-MS/MS)测定陈皮中T-2毒素含量的方法.陈皮用乙腈-0.1%甲酸溶液提取,经PSA(乙二胺-N-丙基硅烷)净化,LCMS/MS电喷雾正离子多反应监测(MRM)模式检测.T-2毒素在1~25μg.L-1的浓度范围内进样量与峰面积呈良好的线性关系(r=0.9996),陈皮中T-2毒素的检测限为2.0μg.kg-1.平均加样回收均为91.86%,RSD为2.88%(n=9).该法操作简便,结果准确,可作为陈皮中T-2毒素残留量检测方法. 相似文献
8.
毛细管气相色谱法测定桔梗中六六六异构体的含量 总被引:3,自引:2,他引:1
运用毛细管气相色谱法测定了桔梗中甲体六六六(α-BHC)、乙体六六六(β-BHC)、丙体六六六(γ-BHC)、丁体六六六(δ-BHC) 4种异构体的残留量.样品以丙酮提取,在氯化钠存在下,以二氯甲烷进行液-液分配,提取液以浓硫酸净化,采用SE-30弹性石英毛细管柱分离样品,ECD检测六六六残留量.检出限为1.6×10-14~3.8×10-13 g/mL,回收率为85.24%~99.86%,峰面积相对标准偏差为0.61%~2.2%. 相似文献
9.
《贵州师范大学学报(自然科学版)》2017,(3)
利用气相色谱-四极杆-飞行时间质谱(GC-QTOF MS)技术建立了油脂食品中23种邻苯二甲酸酯类快速检测方法。样品采用乙腈-甲基叔丁基醚(9∶1,v/v)提取,PSA分散剂净化,经GC-QTOF MS测定,采用外标法定量。在全扫描采集模式下,以特征离子峰的峰面积定量,以化合物的保留时间、精确质量数及谱库检索定准确性。23种化合物在线性范围内均呈现良好的线性关系,相关系数均大于0.99,23种化合物的定量限(S/N=10)为0.05~0.1mg/kg,在0.1~5.0mg/kg 3个添加水平下的平均回收率为79%~112%,相对标准偏差(RSD,n=6)均低于14%。该方法简便、快速、灵敏,可以应用于油脂类食品中23种邻苯二甲酸酯类的同时检测。 相似文献
10.
建立了鱼肉中氯霉素残留量的液相色谱串联质谱测定方法.样品用甲醇直接提取后,经C18固相萃取小柱净化后,注入液相色谱串联质谱仪中进行检测.利用ESI源(负离子模式),C18液相色谱柱,以及SRM方法对样品中的氯霉素进行定性、定量分析.实验结果表明:方法测定结果的相对标准偏差小于6%(n=6),平均回收率大于90%,线性范围为1~10 ng/m L,最低检出限为0.029 ng/m L. 相似文献
11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
12.
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
13.
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
17.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献