高效液相色谱/串联质谱法同时测定虾中氯霉素、甲砜霉素和氟甲砜霉素残留量

用高效液相色谱／串联质谱(LC／MS,／MS)同时测定虾中的氯霉素(CAP)、甲砜霉素(TAP)和氟甲砜霉素(FF)。均质后的虾样品,采用碱化乙酸乙酯提取。浓缩提取物经液．液分配(LLP)去除脂肪,C18固相萃取(SPE)柱净化后,采用LC／MS／MS电喷雾电离(ESI),负离子,多反应监测(MRM)模式检测,外标法定量。检出限为：氯霉素和氟甲砜霉素0．01ng/g;甲砜霉素为0．05ng／g。在添加浓度0．1～2．0ng/g范围内,氯霉素回收率为73．9％～96．0％;甲砜霉素回收率为78．6％～99．5％;氟甲砜霉素回收率为74．9％～103．7％;相对标准偏差(RSD)均小于6．4％。     

Combined use of nuclear magnetic resonance and infrared spectroscopy for studying recognition processes between amphenicolic antibiotics and albumin

Biological reactions are mostly concerned with selective interactions between small ligands and macromolecular receptors. The same ligands may activate responses of different intensities and/or effects in the presence of different receptors. Many approaches based on spectroscopic and non‐spectroscopic methods have been used to study interactions between small ligands and macromolecular receptors, including methods based on NMR and IR spectroscopic analysis of the solution behaviour of the ligand in the presence of receptors. In this work, we investigated the interaction between ovine serum albumin with two amphenicolic antibiotics [chloramphenicol (CAP) and thiamphenicol (TAP)], using a combined approach based on NMR and IR methodologies, furnishing complementary information about the recognition process occurring within the two systems. The two ligands, despite their similar structures, showed different affinities towards albumin. NMR methodology is based on the comparison of selective ( ) and non‐selective ( ) spin–lattice relaxation rates of the ligands in the presence and absence of macromolecular receptors and and temperature dependence analysis. From these studies, the ligand–receptor binding strength was evaluated on the basis of the ‘affinity index.’ The derivation of the affinity index from chemical equilibrium kinetics for both the CAP–albumin and TAP–albumin systems allowed a comparison of the abilities of the two amphenicolic antibiotics to interact with the protein. IR methodology is based on the comparison of the ligand–protein ‘complex’ spectra with those of the non‐interacting systems. On the basis of the differences revealed, a more thorough IR analysis was performed in order to understand the structural changes which occurred on both ligand and protein molecules within the interacting system. Copyright © 2003 John Wiley & Sons, Ltd.     

紫外分光光度法测定甲砜霉素片的含量

根据甲砜霉素的紫外吸收特征,建立了以乙腈-水为溶媒、(225±1)nm为最大吸收波长的紫外分光光度法。方法的线性范围为0.5～25.0μg/mL,平均回收率为99.92％,RSD为0.30％。用对照品比较法测定5批甲砜霉素片的含量,并与中国药典方法的测定结果进行比对,结果表明,两种方法的测定结果基本一致。     

高效液相色谱-电喷雾电离三级四极杆质谱检测动物源食品中氯霉素、甲砜霉素、氟苯尼考残留量

建立了动物源产品中氯霉素、甲砜霉素、氟苯尼考残留量的高效液相色谱-电喷雾电离三级四极杆质谱(LC-ESI-MS/MS)的方法。前处理方法包括添加同位素内标氯霉素-d5,碱化乙酸乙酯提取,C18小柱净化。该方法采用负离子,多反应监测氯霉素四对离子(321.0/151.9,321.0/256.6,321.0/194.2,321.0/175.4),甲砜霉素两对离子(354.1/185.0,354.1/290.0),氟苯尼考两对离子(356.0/335.9,356.0/185.1)和同位素内标氯霉素-d5(326.0/157.1)。该方法线性范围为0.1~1.6μg/kg;对不同基质样品的加标回收率为80%~112.5%;相对标准偏差小于11%;方法的测定低限为0.1μg/kg。     

Determination of bergenin in human plasma after oral administration by HPLC-MS/MS method and its pharmacokinetic study

A highly sensitive, simple and selective high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and applied to the determination of bergenin concentration in human plasma. Bergenin and the internal standard (IS) thiamphenicol in plasma were extracted with ethyl acetate, separated on a C(18 )reversed-phase column, eluted with mobile phase of acetonitrile-water, ionized by negative ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor --> product ions of m/z 327.1 --> 192 for bergenin and 354 --> 185.1 for the IS, respectively. The linear range of the calibration curve for bergenin was 0.25-60 ng mL(-1), with the lowest limit of quantification of 0.25 ng mL(-1), and the intra/inter-day relative standard deviation (RSD) was less than 10%. The method is suitable for the determination of low bergenin concentration in human plasma after therapeutic oral doses, and has been first and successfully used for its pharmacokinetic studies in healthy Chinese volunteers.     

气相色谱-质谱联用法测定动物组织中氯霉素、氟甲砜霉素和甲砜霉素的残留量

建立了气相色谱-负离子化学电离源质谱同时测定动物组织中氯霉素(CAP)、甲砜霉素(TAP)和氟甲砜霉素(FF)残留量的方法。样品用乙酸乙酯提取,正己烷分配去脂肪,再用Florisil柱进一步净化,甲苯作为反应介质,用N,O-双(三甲基硅基)三氟乙酰胺(BSTFA)-三甲基氯硅烷(TMCS)(体积比为99∶1)进行硅烷化处理,用间硝基氯霉素(m-CAP)作为内标进行测定。CAP的检测限可达到0.03 μg/kg,TAP和FF的检测限可达到0.2 μg/kg;上述3种药物的标准曲线的线性相关系数均大于0.99。CAP,FF和TAP的批内测定的精密度(以相对标准偏差表示)依次为5.5%,10.4%和8.8%;批间测定的精密度依次为7.4%,20.7%和19.1%。回收率为80.0%~111.5%,相对标准偏差为1.2%~15.4%。该方法前处理步骤简单,处理后杂质干扰少,灵敏度高,适用性强,可用于猪肉及禽类、水产品等多种动物组织中氯霉素类药物残留的检测。     

高效液相色谱内标法检测鸡血浆中甲砜霉素的浓度

以氟甲砜霉素作内标,乙腈作为提取溶剂,采用高效液相色谱内标法检测鸡血浆中甲砜霉素的浓度。色谱柱为Shim-pack CLC-ODS(150 mm×6 mm,5μm),流动相为乙腈-水(体积比25∶75),流速为1.0 mL/min,检测波长为225 nm,柱温为40℃。在此色谱条件下,在0.25~32.00 mg/L浓度范围内,甲砜霉素浓度与甲砜霉素和氟甲砜霉素峰面积比呈线性关系,相关系数r为0.9999,最低检测浓度为0.1 mg/L;在高、中、低3个浓度水平下日内、日间精密度均大于6.1%(n=5),提取回收率大于98.68%,方法回收率为99.20%~100.25%。建立的方法符合生物样品的分析要求,可用于临床药代动力学研究。     

高效液相色谱-串联质谱法同时测定饲料中氯霉素、甲砜霉素与氟甲砜霉素残留量

建立了饲料中氯霉素(CAP)、甲砜霉素(TAP)、氟甲砜霉素(FF)3种抗生素残留量的高效液相色谱-串联质谱(HPLC-MS/MS)测定方法。样品经碱化乙酸乙酯提取,蒸发浓缩,提取物经正己烷脱脂,液-液分配净化后,采用电喷雾电离源(ESI)负离子多反应监测(MRM)模式检测,内标法定量。氯霉素、氟甲砜霉素和甲砜霉素的线性范围分别为0.2～10.0、0.2～10.0、1.0～50.0μg/L,相关系数(r2)不低于0.990 0;其检出限分别为0.1、0.1、0.5μg/kg,定量下限分别为0.3、0.3、1.5μg/kg。3种抗生素药物的平均回收率为77%～108%,相对标准偏差(RSD)不大于10.9%。     

氯霉素、甲砜霉素与曙红Y的共振瑞利散射光谱及应用

在pH 1.30的酸性介质中,曙红Y(EOSY)分别与氯霉素(CHP)、甲砜霉素(TAP)相互作用形成离子缔合物,使共振瑞利散射(RRS)显著增强并产生新的RRS光谱。CHP–EOSY体系的最大RRS峰位于313nm,线性范围为0.015～0.32 mg.L-1,检出限为0.013 mg.L-1;TAP–EOSY体系的最大RRS峰位于314nm,线性范围为0.018～0.39 mg.L-1,检出限为0.012 mg.L-1。据此发展了以曙红Y为探针,用共振瑞利散射法测定氯霉素、甲砜霉素的方法。方法简便快速,有较高灵敏度,可用于实际样品中氯霉素、甲砜霉素的测定。     

Evolution of dispersive liquid–liquid microextraction method

Dispersive liquid–liquid microextraction (DLLME) has become a very popular environmentally benign sample-preparation technique, because it is fast, inexpensive, easy to operate with a high enrichment factor and consumes low volume of organic solvent. DLLME is a modified solvent extraction method in which acceptor-to-donor phase ratio is greatly reduced compared with other methods. In this review, in order to encourage further development of DLLME, its combination with different analytical techniques such as gas chromatography (GC), high-performance liquid chromatography (HPLC), inductively coupled plasma-optical emission spectrometry (ICP-OES) and electrothermal atomic absorption spectrometry (ET AAS) will be discussed. Also, its applications in conjunction with different extraction techniques such as solid-phase extraction (SPE), solidification of floating organic drop (SFO) and supercritical fluid extraction (SFE) are summarized. This review focuses on the extra steps in sample preparation for application of DLLME in different matrixes such as food, biological fluids and solid samples. Further, the recent developments in DLLME are presented. DLLME does have some limitations, which will also be discussed in detail. Finally, an outlook on the future of the technique will be given.