高效液相色谱法快速测定鸡蛋中5种氟喹诺酮类药物残留

建立了一种检测鸡蛋中环丙沙星、达氟沙星、恩诺沙星、二氟沙星及沙拉沙星残留的高效液相色谱方法。该方法前处理简便快速,样品经低浓度乙腈结合加热促使蛋白质快速沉淀,正己烷脱脂,分离清液后进高效液相色谱仪分析。流动相为0.05 mol/L磷酸/三乙胺溶液-乙腈溶液(80∶20),荧光检测器的激发波长为280 nm,发射波长为450 nm。该方法对环丙沙星和二氟沙星的定量下限为5μg/kg,达氟沙星的定量下限为0.5μg/kg,恩诺沙星的定量下限为2.5μg/kg,沙拉沙星的定量下限为10μg/kg。在定量下限及低、中、高4种加标浓度下,5种氟喹诺酮类药物的平均回收率为92.2%~107.1%,批内相对标准偏差(RSD)为0.6%~5.8%,批间相对标准偏差为1.5%~5.0%。方法具有前处理简单、环保、快捷、准确度和灵敏度高等优点,适合生产线和流通环节鸡蛋样品的快速检测。     

高效液相色谱法同时检测8种喹诺酮类兽药残留量

建立了吡哌酸、氧氟沙星、环丙沙星、单诺沙星、恩诺沙星、沙拉沙星、(噁)喹酸和氟甲喹8种喹诺酮类兽药残留量的高效液相色谱-荧光检测方法. 方法的线性范围: 30～2000 μg/kg, 定量限为30 μg/kg, 检出限为5 μg/kg (吡哌酸为20 μg/kg). 该方法采用基质分散和微波萃取技术进行样品的前处理, 回收率为70.0%～99.5%, 相对标准偏差1.0%～8.5%. 并同固相萃取方法进行了比较, 分别使用了RPS、HLB、MAX 3种固相萃取柱, 其回收率均低于本法. 确立了以Aglient XDB-C18 (5 μm, 150 mm×4.6mm i.d.)色谱柱, H3PO4-纯水-三乙胺-乙腈(pH 3.0)为流动相的最佳色谱条件, 吡哌酸、氧氟沙星、环丙沙星、单诺沙星、恩诺沙星、沙拉沙星的检测波长为: 激发波长285 nm, 发射波长460 nm;(噁)喹酸和氟甲喹为: 激发波长325 nm, 发射波长365 nm. 方法可满足兽药残留检测要求.     

鸡肉中11种喹诺酮类药物多残留的高效液相色谱检测

建立了用荧光检测器同时测定11种喹诺酮类药物(包括诺氟沙星、培氟沙星、环丙沙星、恩诺沙星、氧氟沙星、达氟沙星、洛美沙星、二氟沙星、沙拉沙星、恶喹酸和氟甲喹)在鸡肉中的多残留的高效液相色谱检测方法。鸡肉样品用10%三氯乙酸-乙腈(体积比为7∶3)提取两次并稀释,随后用反相固相萃取柱净化。采用Hypersil BDS-C18色谱柱分离,以乙腈和水为流动相梯度洗脱,荧光检测器用程序编程检测波长检测。11种喹诺酮类药物标准曲线的线性范围为5～1200 μg/L,相关系数大于0.998。在高、中、低三个添加水平下的回收率为56%～119%,批内相对标准偏差为0.4%～16.1%,批间相对标准偏差为1.4%～23.0%。检出限和定量限分别为1～23 μg/kg和4～40 μg/kg。该方法快速、灵敏,达到了兽药残留检测的要求。     

蜂蜜中14种喹诺酮类药物残留的高效液相色谱-串联质谱测定

建立了同时测定蜂蜜中14种喹诺酮类药物残留的高效液相色谱-串联质谱分析方法.蜂蜜中喹诺酮类药物残留用0.05 mol/L磷酸盐缓冲溶液(pH＝3.0)提取,样液过滤后,经Oasis HLB固相萃取柱净化,氢氧化铵-甲醇溶液(体积比1:19)洗脱,蒸干定容后,用反相液相色谱分离,电喷雾正离子模式离子化,用多反应监测方式(MRM)监测,三重四极杆质谱测定.环丙沙星在0.4～100.0μg/kg,噁喹酸在0.4 ～50.0μg/kg,恩诺沙星、沙拉沙星、双氟沙星、依诺沙星、诺氟沙星在1.0～100.0μg/kg,氧氟沙星、单诺沙星、氟罗沙星、奥比沙星、麻保沙星在1.0～50.0μg/kg,司帕沙星、氟甲喹在2.0 ～100.0μg/kg范围内呈线性关系,相关系数r>0.997,在2.0、5.0、10.0、50.0 μg/kg 4个添加水平,回收率为66% ～111%,相对标准偏差(RSD)为1.3% ～13.6%.该方法操作简便,稳定性好,选择性好,灵敏度高,其检出限达1.0μg/kg.     

反相离子对液相色谱法同时测定11种氟喹诺酮类药物的研究

建立了高效液相色谱-荧光法同时测定11种氟喹诺酮类药物的分析方法.主要研究了流动相、流动相配比及流动相的pH对氟喹诺酮分离的影响.确定了液相色谱分析最佳条件.分离条件为:Xbridge Shield RP C18柱,以V(0.10%三氟乙酸)∶V(乙腈)∶V(甲醇)=89∶4∶7为流动相;检测波长为λex=280 nm和λem＝450 nm.方法检出限为:诺氟沙星、环丙沙星、培氟沙星和恩诺沙星0.007μg/mL,单诺沙星0.002 μg/mL,沙拉沙星和氧氟沙星为0.04 μg/mL,二氟沙星和奥比沙星为0.02 μg/mL,依诺沙星、麻保沙星为0.4 μg/mL,各组分回收率在97%～100.2%,相对标准偏差为0.2%～2.9%.     

高效液相色谱同时测定鸡蛋中4种氟喹诺酮类药物残留

建立了固相萃取—反相高效液相色谱同时分析鸡蛋样品中4种氟喹诺酮类药物残留量的方法。对鸡蛋样品的提取及其在C18固相萃取柱上的净化条件进行了研究,采用高效液相色谱分离,荧光检测器检测(λex=280nm,λem=450nm),外标法定量。4种沙星标准曲线的线性回归系数均在0．9999以上,环丙沙星、恩诺沙星、沙拉沙星的线性范围为2．5～500μg／L;达诺沙星为0．5～100μg/L。鸡蛋样品中4种沙星的加标回收率为78．1％～95．7％;相对标准偏差为4．1％～16．2％。环丙沙星、恩诺沙星、沙拉沙星的最低检出限为10μg／kg;达诺沙星的最低检出限为2μg/kg。     

高效液相色谱法检测六种氟喹诺酮类兽药残留前处理的优化

建立了一个检测动物源性食品中6种氟喹诺酮类药物残留的高效液相色谱方法。不同基质的样品前处理对检测影响较大:鱼、肉及肝脏等样品需经过乙腈-0.1 mol/L KH2PO4缓冲液提取,乙腈饱和的正己烷洗涤去除油脂;蛋及乳制品样品用正己烷饱和的乙腈提取,乙腈饱和的正己烷去脂。目标化合物采用高效液相色谱-荧光检测器检测,外标法定量。对市售鸡肉、猪肉、鸡蛋进行检测,添加10、20、50、100μg/kg浓度水平时,回收率在82%~105%之间,相对标准偏差在4%~12%之间,方法的检出限诺氟沙星、环丙沙星、沙拉沙星及单诺沙星为5.0μg/Kg,恩诺沙星、达氟沙星为3.0μg/Kg。     

高效液相色谱-串联质谱法测定蜂蜜中残留的19种喹诺酮类药物

建立了高效液相色谱-电喷雾串联质谱联用测定蜂蜜中恩诺沙星、环丙沙星、诺氟沙星、氧氟沙星、双氟沙星、恶喹酸、氟甲喹、沙拉沙星、司帕沙星、丹诺沙星、氟罗沙星、马波沙星、伊诺沙星、奥比沙星、吡哌酸、培氟沙星、洛美沙星、西诺沙星和萘啶酸等19种喹诺酮类药物残留的方法。比较酸性溶液阳离子固相萃取(PCX柱)、近中性缓冲溶液反相固相萃取（HLB柱）和碱性溶液阴离子固相萃取(PAX柱)3种不同提取净化方法的提取效果,最终选择使用碱性溶液溶解蜂蜜样品,强阴离子固相萃取柱一步富集净化。以甲醇和0.1%甲酸溶液作为流动相,C18作为分析色谱柱,采用梯度洗脱方式进行液相色谱分离,选择离子反应监测模式检测19种喹诺酮类药物,内标方法定量。在1～100 μg/L范围内,19种喹诺酮类药物的线性相关系数均大于0.991。通过实际样品的添加回收试验,方法的定量限（S/N=10）为1.0 μg/kg,3个添加水平的回收率为71%～118%,相对标准偏差为4.2%～6.7%。     

高效液相色谱-串联质谱法测定动物组织中的16种喹诺酮类药物残留

建立了动物组织样品中萘啶酸、恶喹酸、氟甲喹、诺氟沙星、依诺沙星、环丙沙星、洛美沙星、丹诺沙星、恩诺沙星、氧氟沙星、沙拉沙星、二氟沙星、麻保沙星、培氟沙星、司帕沙星、奥比沙星等16种喹诺酮类兽药多残留量的高效液相色谱-串联质谱测定方法。用酸性乙腈萃取样品中的16种喹诺酮类药物残留,然后用正己烷脱脂,旋转蒸发浓缩,以Inertsil C8-3色谱柱分离,在正离子模式下以电喷雾电离串联质谱进行测定。在10,50,100 μg/kg 3个加标水平下进行了验证试验,方法的线性范围为10~100 μg/kg,平均回收率为62.4%~102%,相对标准偏差为1.4%~11.9%。该方法简便、快速、准确,各项技术指标满足国内外法规的要求,可用于鸡肉、鸡肝和鱼肉等动物组织样品中喹诺酮类药物多残留的确证检测。     

液相色谱-串联质谱法检测水产品中15种喹诺酮类药物残留量

建立了液相色谱-串联质谱技术同时检测水产品中15种喹诺酮类药物(氟罗沙星、氧氟沙星、依诺沙星、诺氟沙星、环丙沙星、恩诺沙星、洛关沙星、单诺沙星、奥比沙星、双氟沙星、沙拉沙星、司帕沙星、口恶喹酸、萘啶酸、氟甲喹)残留量的方法.试样中残留的喹诺酮类药物采用乙腈提取,提取液经正已烷液液分配脱脂后,以强阳离子固相萃取小柱净化,液相色谱.串联质谱法测定.对液/质分离条件与样品前处理条件进行了优化,并对喹诺酮类药物在分析过程的稳定性进行了研究.15种喹诺酮类药物在1.0～100 μg/L范围内线性关系良好,相关系数为0.9924～0.9992.在0.002～0.04 mg/kg浓度范围内,平均加标回收率在79.9%～93.8%;相对标准偏差为4.8%～14.6%.方法可满足水产品中喹诺酮类药物多残留检测与确证的需要.     

Determination of residues of enrofloxacin and its metabolite ciprofloxacin in chicken muscle by capillary electrophoresis using laser-induced fluorescence detection

A method for the residue analysis of the veterinary antimicrobial agent enrofloxacin and its active desethyl metabolite ciprofloxacin in chicken muscle tissue has been developed and validated. The detection of the analytes was performed by laser-induced fluorescence (LIF) detection using a HeCd laser (lambda(ex) = 325 nm) providing an enhancement in sensitivity and selectivity compared to conventional UV detection. The assay has been validated with satisfying results. The limits of quantification for enrofloxacin and ciprofloxacin were 5 microg/kg and 20 microg/kg, respectively, with a fivefold preconcentration yielded by a sample clean-up with a simple liquid-liquid extraction procedure. Calibration graphs were linear from 5 to 1000 microg/kg for enrofloxacin and from 20 to 1000 microg/kg for ciprofloxacin. The assay allows the detection of contaminated muscle samples at the required maximum residue limit of the European Union, which is 100 microg/kg for the sum of enrofloxacin and ciprofloxacin.     

Quantitation of nine quinolones in chicken tissues by high-performance liquid chromatography with fluorescence detection

A simple reversed-phase high-performance liquid chromatographic method was developed and validated for simultaneous analysis of nine quinolones (ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, flumequine, marbofloxacin, nalidixic acid, oxolinic acid, sarafloxacin) in chicken tissue. The analytes were extracted from homogenized muscle using an acetonitrile basic solution. After centrifugation and partial evaporation, direct injection was possible. Three different HPLC conditions were applied to quantify the residual quinolones. Separation was achieved on a PLRP-S column and detection was performed with a monochromator fluorescence detector. The recovery, the limit of detection, the limit of quantification, the accuracy and the precision of the method were evaluated from spiked tissue samples at concentration levels ranging from 15 microg kg(-1) to 300 microg kg(-1) according to the maximum residue limit of each quinolone. This method is also suitable for porcine, bovine, ovine and fish muscle tissue.     

Determination of enrofloxacin and its metabolite ciprofloxacin in goat milk by high-performance liquid chromatography with diode-array detection. Optimization and validation

A high-performance liquid chromatography-diode array detection method (HPLC-DAD) combined with liquid chromatography-mass spectrometry was developed for the determination of enrofloxacin and its metabolite ciprofloxacin in goat milk. The HPLC-DAD method validation was compliant with the "DG SANCO 1805/2000" European regulation. The residues were extracted from milk with phosphate buffer, purified on a C18 Speedisk cartridge SPE (Baker) and then analysed using HPLC-DAD set at 277 nm. The decision limit (CCa) calculated by spiking samples at 100 microg/kg with both analytes, taking into account the maximum residue limit (MRL) of 100 microg/kg established by the European Union for the sum of enrofloxacin and its metabolite ciprofloxacin in milk, was 105.3 microg/kg for enrofloxacin and 105.5 microg/kg for ciprofloxacin. The detection capability (CCbeta) was 110.7 and 110.9 microg/kg for enrofloxacin and ciprofloxacin, respectively. The mean recoveries of the method, calculated by spiking samples at 50, 100 and 150 microg/kg were 84% for enrofloxacin and 88% for ciprofloxacin. The limit of quantification was 20 microg/kg for both analytes. The HPLC-DAD validated method was successfully applied for the first time in goats milk, and proved to be suitable for the sensitive and accurate quantification and confirmation analysis of enrofloxacin and ciprofloxacin for regulatory purposes.     

Multiresidue determination of eleven quinolones in milk by liquid chromatography with fluorescence detection

A liquid chromatographic method with fluorescence detection was developed for simultaneous determination of norfloxacin, ofloxacin, ciprofloxacin, pefloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, and flumequine in milk The samples were extracted with 10% trichloroacetic acid/acetonitrile (9 + 1, v/v) and cleaned by Strata-X reversed-phase solid-phase extraction cartridges. The 11 quinolones were separated on a reversed-phase C18 column (Hypersil BDS-C18) with mobile phase gradient elution and detected with fluorescence by means of a wavelength program. The recoveries for milk fortified with the 11 quinolones at 3 levels were 69-88% with acceptable relative standard deviations of <9% (intraday) and <14% (interday). The limits of detection were 23 microg/L for enrofloxacin, and 1-9 microg/L for the other 10 quinolones.     

Determination of fluoroquinolone residues in animal tissues using Escherichia coli as indicator organism

Three strains of Escherichia coli (ATCC 128, 10536, and 25922) and one strain of Bacillus subtilis (ATCC 3491) were compared as indicator microorganisms in microbial inhibition tests for their ability to detect fluoroquinolone residues. E. coli strains 128 and 10536 were most susceptible to fluoroquinolone residues, with detection limits of 35-50 micrograms/kg for enrofloxacin. Of the 2 strains, E. coli 10536 was slightly less susceptible. Ciprofloxacin was detected consistently by E. coli 128 at 30 micrograms/kg. Other fluoroquinolone drugs of veterinary interest detected by E. coli 128 were sarafloxacin and difloxacin at 100-250 micrograms/kg concentration. E. coli 25922 yielded 100% sensitivity in detection of enrofloxacin only at the 250 micrograms/kg concentration, and ciprofloxacin and sarafloxacin at 200 micrograms/kg. B. subtilis detected only enrofloxacin 100% of the time at 250 micrograms/kg. The E. coli strains tested were insensitive to other antibacterials commonly used in animals, with the exception of ceftiofur which was detected by E. coli 128 and 10536 at 500 micrograms/kg. The B. subtilis strain was not effective in detecting the fluoroquinolone drugs, whereas the E. coli strains were selective for the fluoroquinolones. E. coli 128 was 100% effective in detecting enrofloxacin and ciprofloxacin in spiked diaphragm homogenate samples at 50 micrograms/kg. Of the microorganisms tested, E. coli strain ATCC 128 was highly suitable as an indicator microorganism in a microbial inhibition assay for selective detection of fluoroquinolone antibacterial residues in animal tissues.     

Multiresidue analysis of fluoroquinolone antibiotics in chicken tissue using automated microdialysis-liquid chromatography

An efficient procedure for the simultaneous extraction and analysis of six fluoroquinolone (FQ) antibiotics is developed using an automated microdialysis-liquid chromatographic (LC) system. In this method, samples extracted from chicken liver and muscle are further purified by microdialysis, separated on an LC column, and the FQs detected by their fluorescence. Recoveries from fortified chicken liver and muscle samples are at least 70% with limits of quantitation (microg/kg) for the FQs in liver (and muscle) as follows: 0.3 (0.4) for danofloxacin, 0.8 (0.2) for desethylene ciprofloxacin, 2 (1) for norfloxacin, 2 (0.8) for enrofloxacin, 3 (1) for ciprofloxacin, and 5 (2) for sarafloxacin. Enrofloxacin and ciprofloxacin are determined in enrofloxacin-incurred chicken liver and muscle samples using this method.     

Quantitation and validation of fluoroquinolones in eggs using liquid chromatography/tandem mass spectrometry

Fluoroquinolone antibiotics are labeled for very limited veterinary use for treatment of some animals and pets, but they are not authorized for food animals in Canada, including egg-producing birds. Because they are approved for other animals, however, fluoroquinolones may appear in eggs through off-labeling or accidental use. This method is capable of quantitating and confirming the presence of 4 fluoroquinolones, ciprofloxacin, danofloxacin, enrofloxacin, and sarafloxacin, over the concentration range 1 to 60 microg/kg (ppb) using 2 internal standards, norfloxacin or lomefloxacin. The compounds are extracted with acidic acetonitrile, isolated using Oasis HLB solid-phase extraction, and quantitated by liquid chromatography/tandem mass spectrometry at 2 transitions. The limits of detection (microg/kg) were evaluated from between-day experiments as: ciprofloxacin, 0.22; danofloxacin (m/z 314), 0.32; enrofloxacin, 0.22; and sarafloxacin, 0.31. The values for the decision limit, CCalpha were 0.33, 0.36, 0.30, and 0.45 microg/kg, respectively.     

Effective cleanup for the determination of six quinolone residues in shrimp before HPLC with diode array detection in compliance with the European Union Decision 2002/657/EC

A high‐performance liquid chromatographic method was developed for the determination of six quinolone residues (ciprofloxacin, enrofloxacin, sarafloxacin, oxolinic acid, nalidixic acid, and flumequine) in shrimp tissue samples. Separation was carried out by a LiChrospher® 100 RP‐8e column, running at a 22 min gradient elution program, and the mobile phase consisted of citric acid (0.4 mol/L), acetonitrile and methanol. Detection was achieved by a diode array detector, monitoring at 255 and 275 nm. Sample preparation included initial extraction with citric acid solution and further clean‐up by solid‐phase extraction, employing Lichrolut RP‐18 cartridges. Validation was performed according to the European Union Decision 2002/657/EC. The detection capability was 127.2 μg/kg for ciprofloxacin, 115.2 μg/kg for enrofloxacin, 126.2 μg/kg for sarafloxacin, 113.1 μg/kg for oxolinic acid, 125.2 μg/kg for nalidixic acid, and 239.0 μg/kg for flumequine. Recoveries ranged between 83.0 and 121.6%. The Youden test was applied to study the method ruggedness.