Micropreparative fractionation of DNA fragments on metathesis-based monoliths: influence of stoichiometry on separation

New antibiotics were recently developed, among which are the (fluoro)quinolones. This paper presents an analytical method which allows the determination of 11 (fluoro)quinolones in swine kidneys: norfloxacin, ofloxacin, cinoxacin, oxolinic acid, nalidixic acid, flumequine, enrofloxacin, enoxacin, ciprofloxacin, danofloxacin and marbofloxacin. The procedure involves a rapid and efficient pre-treatment by solid-phase extraction (recoveries 83-98%), followed by the sensitive and selective determination of all compounds in a single run using LC-ESI-MS-MS. Multiple reaction monitoring (MRM) was used for selective detection of each (fluoro)quinolone. Quinine was selected as internal standard. The accuracy of the method, expressed as recovery, was between 89 and 109%; the repeatability had a maximum RSD lower than 15%. The limits of detection (LOD) were much lower than the respective Maximum Residue Limits (MRL)/4.     

Comparison of Three Analytical Methods for the Determination of Quinolones in Pig Muscle Samples

This work presents a comparison between three analytical methods developed for the simultaneous determination of eight quinolones regulated by the European Union (marbofloxacin, ciprofloxacin, danofloxacin, enrofloxacin, difloxacin, sarafloxacin, oxolinic acid and flumequine) in pig muscle, using liquid chromatography with fluorescence detection (LC–FD), liquid chromatography–mass spectrometry (LC–MS) and liquid chromatography-tandem mass spectrometry (LC–MS/MS). The procedures involve an extraction of the quinolones from the tissues, a step for clean–up and preconcentration of the analytes by solid-phase extraction and a subsequent liquid chromatographic analysis. The limits of detection of the methods ranged from 0.1 to 2.1 ng g⁻¹ using LC–FD, from 0.3 to 1.8 using LC–MS and from 0.2 to 0.3 using LC–MS/MS, while inter- and intra-day variability was under 15 % in all cases. Most of those data are notably lower than the maximum residue limits established by the European Union for quinolones in pig tissues. The methods have been applied for the determination of quinolones in six different commercial pig muscle samples purchased in different supermarkets located in the city of Granada (south-east Spain).

     

Comparison of Three Analytical Methods for the Determination of Quinolones in Pig Muscle Samples

This work presents a comparison between three analytical methods developed for the simultaneous determination of eight quinolones regulated by the European Union (marbofloxacin, ciprofloxacin, danofloxacin, enrofloxacin, difloxacin, sarafloxacin, oxolinic acid and flumequine) in pig muscle, using liquid chromatography with fluorescence detection (LC–FD), liquid chromatography–mass spectrometry (LC–MS) and liquid chromatography-tandem mass spectrometry (LC–MS/MS). The procedures involve an extraction of the quinolones from the tissues, a step for clean–up and preconcentration of the analytes by solid-phase extraction and a subsequent liquid chromatographic analysis. The limits of detection of the methods ranged from 0.1 to 2.1 ng g^?1 using LC–FD, from 0.3 to 1.8 using LC–MS and from 0.2 to 0.3 using LC–MS/MS, while inter- and intra-day variability was under 15 % in all cases. Most of those data are notably lower than the maximum residue limits established by the European Union for quinolones in pig tissues. The methods have been applied for the determination of quinolones in six different commercial pig muscle samples purchased in different supermarkets located in the city of Granada (south-east Spain).     

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.     

超高效液相色谱-串联质谱法同时测定食品级聚苯乙烯和聚乙烯色母粒中33种初级芳香胺

建立了超高效液相色谱-三重四极杆质谱(UPLC-MS/MS)同时测定食品级聚苯乙烯(PS)和聚乙烯(PE)色母粒中33种初级芳香胺(PAAs)的检测方法。PS色母粒用二氯甲烷溶解,超声提取后加入甲醇沉淀,并将提取液过石墨化碳固相萃取柱净化;PE色母粒用二氯甲烷超声溶胀提取;将PS色母粒过柱液和PE色母粒提取液浓缩,浓缩液用甲醇-水(1:9, v/v)定容至2 mL, 0.22 μm膜过滤后上机检测。采用BEH Phenyl色谱柱(100 mm×2.1 mm, 1.7 μm),以0.07%(v/v)甲酸甲醇溶液-水(1:9, v/v)为流动相,梯度洗脱分离,UPLC-MS/MS多反应监测(MRM)模式检测,同位素内标法定量。优化了色谱分离条件、质谱碎裂电压、碰撞能量等,并考察了提取时间、提取溶剂、浓缩方式等对回收率的影响。33种PAAs的方法检出限为6~10 μg/kg,定量限为20~30 μg/kg, 2种不同基质样品在20、100、200 μg/kg等3个添加水平的平均回收率为61.3%~119.8%,相对标准偏差(RSD)为1.4%~14.8%。本方法操作简便、快速、准确、灵敏度高,能满足相关测定要求。     

液相色谱-串联质谱法同时测定化妆品中的25种喹诺酮类药物

建立了直接提取结合液相色谱-电喷雾串联质谱同时测定化妆品中丹诺沙星、恩诺沙星、氟甲喹、恶喹酸、环丙沙星、沙拉沙星、萘啶酸、诺氟沙星、氧氟沙星等25种喹诺酮类药物的方法。样品经酸性乙腈提取和正己烷脱脂净化,采用Poroshell EC-C₁₈色谱柱分离,含0.1%甲酸的乙腈-水溶液为流动相进行梯度洗脱,电喷雾串联质谱正离子模式扫描,多反应监测(MRM)模式检测,外标法定量。实验通过空白基质液配制标准溶液,以降低基质对离子化干扰造成的基质效应,25种喹诺酮类药物在1~200 mg/kg范围内线性关系良好,相关系数(r)在0.999以上。方法的检出限为1.0 mg/kg,在1、5、10 mg/kg 3个加标水平下,水、乳、霜型化妆品中加标回收率为87.4%~105%,相对标准偏差(RSD)为4.54%~19.7%(n=6)。结果表明,该方法简便、快速、准确,适用于化妆品中25种喹诺酮类药物的测定。     

分散固相萃取-高效液相色谱-串联质谱法同时测定畜禽肉中63种兽药残留

建立了分散固相萃取-高效液相色谱-串联质谱(dispersive-SPE-HPLC-MS/MS)同时测定畜禽肉中 β-内酰胺类、喹诺酮类、磺胺类、磺胺类增效剂和抗寄生虫类共5类63种兽药残留的新方法。样品经0.1 mol/L Na₂EDTA溶液及含1% (体积分数)乙酸的乙腈溶液涡旋提取,提取液经C18分散固相萃取净化后,用Poroshell EC-C18色谱柱(100 mm×2.1 mm, 2.4 μm)分离,在电喷雾离子源正离子模式下以动态多反应监测(DMRM)方式采集数据并做定性筛查和定量分析。63种药物在相应的浓度范围内线性关系良好,相关系数均大于0.99;不同畜禽肉(猪肉、牛肉及鸡肉)在3个不同添加水平下的平均回收率为62.2%~112.0%,相对标准偏差(RSD)为3.1%~16.3%,检出限(LOD, S/N≥3)和定量限(LOQ, S/N≥10)分别为0.1~3.0 μg/kg和0.5~10.0 μg/kg。该方法简便快速、灵敏可靠,适用于畜禽产品中兽药多残留的同时快速定性筛查和定量分析。     

超高效液相色谱-三重四极杆质谱法同时测定美术颜料中33种游离态初级芳香胺

建立了超高效液相色谱-三重四极杆质谱法(UPLC-MS/MS)同时测定水粉画颜料、油画颜料、丙烯画颜料等美术颜料中33种初级芳香胺(PAAs)的检测方法。样品中的初级芳香胺用乙腈提取,经离心分离、氮吹浓缩后,以甲醇-水(1:9, v/v)定容至2 mL, 0.22 μm膜过滤后上机检测。采用BEH Phenyl柱(100 mm×2.1 mm, 1.7 μm),以含0.07%(v/v)甲酸的甲醇溶液-水(1:9, v/v)为流动相,梯度洗脱分离,UPLC-MS/MS多反应监测模式(MRM)检测,同位素内标法定量。方法优化了色谱分离条件、质谱碎裂电压、碰撞能量等,并考察了提取时间、提取溶剂、浓缩方式等对回收率的影响。33种初级芳香胺的方法检出限为5~50 μg/kg,定量限为15~150 μg/kg, 3种不同基质样品在3个添加水平的平均回收率为70.1%~115.8%,相对标准偏差(RSD)为2.1%~15%。本方法操作简便、快速、准确、灵敏度高,能满足相关测定的要求。     

An automated method for the simultaneous determination of pravastatin, 3-hydroxy isomeric metabolite, pravalactone and fenofibric acid in human plasma by sensitive liquid chromatography combined with diode array and tandem mass spectrometry detection

In this study, a sensitive and selective method based on liquid chromatography combined with diode array and tandem mass spectrometry detection (LC-DAD-MS/MS) was developed for the simultaneous quantitative determination of fenofibric acid, pravastatin and its main metabolites in human plasma. In this method, an automated solid-phase extraction (SPE) on disposable extraction cartridges (DECs) is used to isolate the compounds from the biological matrix and to prepare a cleaner sample before injection and analysis in the LC-DAD-MS/MS system. On-line LC-DAD-MS/MS system using an atmospheric pressure ionization (TurboIonSpray) was then developed for the simultaneous determination of pravastatin, 3-hydroxy isomeric metabolite (3-OH metab), pravalactone and fenofibric acid. The separation is obtained on an endcapped dodecyl silica based stationary phase using a mobile phase consisting of a mixture of acetonitrile, methanol and 5mM ammonium acetate solution (30:30:40, v/v/v). Sulindac and triamcinolone were used as internal standards (ISs). The detection of the fenofibric acid and sulindac was achieved by means of a DAD system. The MS/MS ion transitions monitored were m/z 442.2-->269.1, 442.2-->269.1, 424.3-->183.0 and 435.2-->397.2 for pravastatin, 3-OH metab, pravalactone and triamcinolone, respectively. The method was validated regarding stability, selectivity, extraction efficiency, response function, trueness, precision lower limit of quantitation and matrix effect. The limits of quantitation (LOQs) were around 0.50 ng/ml for pravastatin, 0.25 ng/ml for 3-OH metab, 0.05 ng/ml for pravalactone and 0.25 microg/ml for fenofibric acid.     

Determination of quinolones in chicken tissues by liquid chromatography with ultraviolet absorbance detection

This paper presents an analytical method for the determination of quinolones in chicken tissues. The procedure involves pre-treatment by solid-phase extraction (SPE) and subsequent liquid chromatography (LC) with UV absorbance detection. Different SPE disposable cartridges and extractants of the tissue samples were tested, and various columns were systematically tested. The mobile phase was composed of acetonitrile and citric buffer at pH 4.5, with an initial composition of acetonitrile-water (12:88, v/v) and using linear gradient elution. Recoveries were 66-91% in the concentration range 30-300 microg kg(-1). The detector response was linear in this range. The limits of detection were 16-30 microg kg(-1). These values were lower than the maximum residue limits established by the European Union.     

超高效液相色谱-电喷雾串联四极杆质谱法同时测定配合饲料中29种兽药

建立了同时测定配合饲料中喹诺酮类、磺胺类、大环内酯类和硝基呋喃类共计29种兽药的超高效液相色谱-电喷雾串联四极杆质谱(UPLC-ESI-MS/MS)检测方法。饲料样品用甲醇-乙腈(1:1, v/v)混合溶液提取,提取液经Oasis HLB固相萃取柱净化,采用UPLC-ESI-MS/MS检测。以甲醇和含0.1%(v/v)甲酸的水溶液作为流动相,进行梯度洗脱,用C18色谱柱分离,正离子模式扫描,多反应监测模式检测。29种兽药在0.01～5.0 mg/L范围内线性关系良好,相关系数(r)均大于0.99;在复合预混饲料、全价配合饲料、浓缩饲料中4个添加水平下29种兽药的平均回收率在61.2%～94.3%范围内,相对标准偏差(RSD)为2.2%～15.0%;方法的检出限(以信噪比大于10计)为0.01 mg/kg或0.05 mg/kg。该方法简便、快速、准确,重现性好,灵敏度高,适用于配合饲料中多种兽药的同时检测。     

Development of analytical methods for multiresidue determination of quinolones in pig muscle samples by liquid chromatography with ultraviolet detection, liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry

This paper presents a comparison between liquid chromatography with ultraviolet detection (LC-UV), liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods developed for the multiresidue determination of 8 quinolones, around their maximum residue levels (MRLs) in pig muscle. The procedure involves common extraction of the quinolones from the tissues by traditional extraction, a step for clean-up and preconcentration of the analytes by solid-phase extraction (SPE) and a subsequent liquid chromatographic analysis. The methods present satisfactory results of linearity, precision and limits of quantification much lower than the MRLs established by the European Union for quinolones in pig tissues.     

超高效液相色谱-串联质谱法同时测定粮食及肉制品中的24种工业染料

建立了测定粮食及肉制品中24种禁用工业染料的超高效液相色谱-串联质谱法。样品经甲醇、乙腈提取后,过WAX固相萃取柱净化。采用ACQUITY UPLC BEH C18分析柱分离,以10 mmol/L乙酸铵-0.2%甲酸水溶液和甲醇-乙腈(7:3, v/v)为流动相梯度洗脱,多反应监测(MRM)模式测定。24种染料的相关系数R²均大于0.99,回收率在61%~116%之间,方法的精密度(RSD, n=6)小于13%,定量限在0.1~4.0 μg/kg。该方法灵敏度高,操作简单、高效,适合于粮食及肉制品中24种禁用工业染料的同时定量及确证分析。     

Rapid determination of quinolones in cosmetic products by ultra high performance liquid chromatography with tandem mass spectrometry

This study developed an improved analytical method for the simultaneous quantification of 13 quinolones in cosmetics by ultra high performance liquid chromatography combined with ESI triple quadrupole MS/MS under the multiple reaction monitoring mode. The analytes were extracted and purified by using an SPE cartridge. The limits of quantification ranged from 0.03 to 3.02 μg/kg. The precision for determining the quinolones was <19.39%. The proposed method was successfully developed for the determination of quinolones in real cosmetic samples.     

加速溶剂萃取-高效液相色谱-串联质谱联用测定莱州湾海水养殖区野生鱼肌肉中19种抗生素及2种磺胺代谢产物残留

建立了加速溶剂萃取-高效液相色谱-串联质谱同时检测鱼肌肉中19种抗生素及2种磺胺代谢产物残留量的分析方法。样品以甲醇为萃取溶剂,采用加速溶剂萃取仪萃取,并在萃取池内以C18填料作为吸附剂进行同步净化。提取液经冷冻离心去除生物杂质后,经氮吹浓缩、定容,以高效液相色谱-串联质谱分析。采用Xterra MS C18色谱柱分离,以0.1%(体积分数)甲酸水溶液(含0.1%甲酸铵)为流动相A,以甲醇-乙腈(1:1, v/v)为流动相B。方法的加标回收率为55.2%~113.3%,相对标准偏差为0.1%~17.6%(n=6),方法的检出限为0.003~0.6 ng/g。以该方法对莱州湾海水养殖区内采集的野生鱼肌肉样品进行分析,共检出6种抗生素。该方法简便、快速、灵敏度高,为研究抗生素的暴露水平和环境行为奠定了基础。     

分散固相萃取-超高效液相色谱-串联质谱法同时检测火锅食材中11种喹诺酮类药物

建立了一种固相分散萃取-超高效液相色谱-串联质谱(QuEChERS-UPLC-MS/MS)同时检测火锅食材中11种喹诺酮类药物的方法。样品用5%甲酸乙腈溶液提取后加入盐析剂分层,提取液中加入C18和PSA填料进行基质分散固相净化,浓缩后经Poroshell 120 EC-C18柱分离,用电喷雾离子源正离子多反应监测(MRM)模式串联质谱进行检测。11种药物在1.0~100.0 μg/kg范围内具有较好的线性关系,相关系数均大于0.998。该方法检出限(LOD)为1.8~3.1 μg/kg,定量限(LOQ)为6.0~10.3 μg/kg。11种药物的回收率为70.1%~100.3%,相对标准偏差(RSD)为2.42%~10.88%。该方法简便快速、灵敏度高、准确度好、使用范围广,可作为火锅食材中11种喹诺酮类药物残留的确证方法。     

超高效液相色谱-四极杆-飞行时间质谱法同时测定猪肉中多类兽药残留

建立了超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF MS)快速检测猪肉中6类33种兽药残留的分析方法。样品采用QuEChERS方法进行前处理(5%(v/v)乙酸乙腈溶液提取,C18和NH₂吸附剂净化),采用ZORBAX SB-C18色谱柱(100 mm×2.1 mm, 3.5 μm)分离,以乙腈-0.1%(v/v)甲酸水溶液(含5 mmol/L乙酸铵)为流动相,梯度洗脱,Q-TOF MS电喷雾正离子模式分析检测。在全扫描采集模式下,以准分子离子峰的峰面积定量,以化合物的色谱保留时间和精确质量数定性。在Target MS/MS采集模式下,通过碎片离子的精确质量数进一步确证化合物。33种化合物在各自的线性范围内均呈现良好的线性关系,相关系数均大于0.99, 33种化合物的定量限(S/N=10)为2.5~100 μg/kg,添加回收率为67.0%~109.0%,相对标准偏差(RSD,n=6)均不高于15.1%。该方法简便、快速、灵敏,适用于猪肉中多类兽药残留的同时检测。     

固相萃取-高效液相色谱-荧光检测土壤中喹诺酮类抗生素

建立了固相萃取-高效液相色谱-荧光(HPLC-FLD)检测土壤中4种喹诺酮类抗生素的分析方法.样品采用50% Mg(NO_3)_2-10% NH_3 · H_2O(96∶ 4,V/V)超声提取,过HLB柱富集净化,再用乙腈-0.067 mol/L H_3PO_4溶液洗脱.采用高效液相色谱-荧光检测器,以乙腈-0.067 mol/L H_3PO_4(用三乙胺调节至pH 2.5)为流动相,于激发波长280 nm、发射波长450 nm处进行检测.土壤样品中4种喹诺酮类抗生素的加标回收率在60.4%～99.3%之间,检出限为0.58～1.0 μg/kg.对蔬菜基地土壤样品分析结果表明,本方法能够满足实际样品的分析要求,4种喹诺酮类抗生素均被检出,土壤中抗生素污染问题值得关注.     

The Rapid Analysis of Antibiotics in Animal Meat and Egg Using a Novel SEP Method and UPLC–MS/MS

A simple and sensitive method for the determination of 39 antibiotics, including sulfonamides and quinolones, in pork, chicken, fish tissues and eggs, has been developed. The sample preparation included ultrasound-assisted extraction (UAE) with 0.1% formic acid in 90:10 acetonitrile/water (v:v) and a final clean-up with Oasis PRiME HLB, a new reversed phase SPE without traditional pre-equilibration and washing steps before eluting SPE. Analysis was performed by ultra-performance liquid chromatography coupled to tandem quadrupole mass spectrometry (UPLC–MS/MS). The positive ionization in multiple reaction monitoring mode (MRM) and product ion confirmation scan (PICs) were used in the method. The PICs provides additional confirmation for compound identification through acquisition of MS/MS spectra in the same injection and a means of verifying that the signal from the MRM peak is from the compound of interest. In particular, single test is simultaneously able to gain both quantitative MRM and qualitative full-scan MS/MS data without the need for long analysis times or repeat injection. All solvent and matrix-matched calibration curves showed excellent correlation coefficient >0.990, with the dynamic range 0.2–100 ng mL^?1. For over 90% of the analytes, the recoveries were between 60 and 120% in all matrices studied at three spiked levels of low, medium, and high concentrations, with the intra-day precision values in the range of 2.7–20.0% and the inter-day precision values in the range of 6.2–21.3%. The limits of detection (LODs) and limits of quantification (LOQs) of all drugs were 0.05–2.6 and 0.12–5.6 μg kg^?1, respectively. A weak matrix effect was observed for most of the compounds in four complex samples. The proposed method was proven very simple, fast, sensitive, and selective and has been successfully applied in real samples from local markets and farms.     

高效液相色谱法同时测定防晒类化妆品中15种紫外线吸收剂

建立了一种反相高效液相色谱同时测定防晒类化妆品中15种紫外线吸收剂的分析方法。化妆水、乳液、膏霜和蜡质样品中首先加入四氢呋喃(含2 g/L氢氧化铵),涡旋、振荡、混匀(若蜡质样品仍分散不完全,可超声振荡加热至50 ℃),再加入80%(v/v)甲醇水溶液振荡混匀、超声提取、离心、过滤后,采用XTerra MS C₁₈柱分离,经水(含0.1%(v/v)甲酸)和甲醇(含0.1%(v/v)甲酸)梯度洗脱,以二极管阵列检测器检测,检测波长为280 nm和311 nm,外标法定量。实验中对不同基质类型样品的前处理条件(样品分散溶剂、萃取溶剂和萃取时间等)进行了重点优化。结果表明,15种紫外线吸收剂在各自的线性范围内呈良好的线性关系(r²≥0.9991),方法的定量限为1.2~5.1 μg/g,在低、中、高3个添加水平下的回收率为84.2%~100.7%,相对标准偏差(RSD)为0.9%~9.5%。该分析方法分离效果好、灵敏度高、定量准确,可用于防晒类化妆品的实际检测。