TiO2修饰磁性石墨烯-通过型固相萃取净化人血中氯霉素、甲砜霉素和氟甲砜霉素

采用TiO₂修饰磁性石墨烯作为通过型固相萃取柱填料,并用于净化去除血液样品中磷脂类物质的干扰,建立了一种快速、高效、准确的测定人血中残留氯霉素、甲砜霉素与氟甲砜霉素的超快速液相色谱-串联质谱分析方法。样品经乙腈提取,使用TiO₂修饰磁性石墨烯-通过型固相萃取柱进行净化处理,以Eclipse Plus C18色谱柱（100 mm×2.1 mm,1.8 μm）分离,以0.08%（v/v）氨水溶液与0.08%（v/v）氨水乙腈溶液为流动相梯度洗脱,电喷雾离子源多反应监测负离子模式下检测,采用内标法定量。3种目标化合物在0.1~10.0 μg/L范围内具有良好的线性（决定系数r²>0.999）,定量限（S/N>10）为0.056~0.082 μg/L,目标化合物的加标回收率为90.0%~105%,相对标准偏差为1.2%~6.6%。该方法可用于临床血样中残留氯霉素、甲砜霉素与氟甲砜霉素的快速筛查和确证分析。     

Simultaneous determination of residues of chloramphenicol, florfenicol, florfenicol amine, and thiamphenicol in shrimp tissue by gas chromatography with electron capture detection

A gas chromatographic (GC) method is presented for determining residues of chloramphenicol (CAP), florfenicol (FF), florfenicol amine (FFa), and thiamphenicol (TAP) in shrimp tissues, with meta-nitrochloramphenicol (mCAP) as the internal standard. The composited shrimp is extracted with basic ethyl acetate, followed by an acetonitrile-basic ethyl acetate mixture. This extract is centrifuged, filtered, evaporated, and reconstituted in water; the reconstituted extract is acidified, defatted with hexane, and passed through a propylsulfonic acid (PRS) and C18 solid-phase extraction (SPE) system. The C18 SPE column is eluted with methanol, and the PRS SPE column is eluted with basic MeOH plus counter ion. The combined eluates are evaporated, reconstituted in acetonitrile, and derivatized with Sylon BFT. After derivatization, the addition of toluene directly to the sample, followed by the addition of basic water, quenches the derivatization process. After centrifugation, the organic layer is carefully removed, and the analytes are determined by GC with electron capture detection. Shrimp tissues were fortified with fenicols (i.e., CAP, FF, FFa, and TAP) at 5, 10, 20, 40, and 80 ng/mL. Overall recoveries were 88, 101, 91, and 84% with overall interassay (between-day) variabilities (i.e., relative standard deviations) of 5.3, 9.4, 12.8, and 7.4% for CAP, FF, FFa, and TAP, respectively. The method detection limits were calculated as 0.7, 1.4, 2.4, and 1.3 ng/g (ppb) for CAP, FF, FFa, and TAP, respectively, based on a 10 g sample. The quantitation limit as determined empirically by this method is the lower limit of the standard curve, which is about 5 ng/g (ppb) for each analyte.     

Determination of malachite green and leucomalachite green in a variety of aquacultured products by liquid chromatography with tandem mass spectrometry detection

A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for determining the residues of malachite green (MG) and leucomalachite green (LMG) in a number of aquatic species. MG and its metabolite were extracted from homogenized tissues with a perchloric acid-acetonitrile solution; the extract was centrifuged; and an aliquot was taken, concentrated, and passed through a chemically bonded octadecyl C18 solid-phase extraction column. The compounds of interest were eluted with acetonitrile, and the eluate was evaporated to dryness. The residue was dissolved in acetonitrile and diluted with water in preparation for analysis by LC/MS/MS. MG and its metabolite were determined by reversed-phase LC using a Luna C18 column with an ammonium hydroxide-formic acid buffer in acetonitrile gradient and MS/MS detection using multiple reaction monitoring. Calibration curves were linear for all analyses between 5 and 500 pg injected for both analytes, with recoveries ranging from 81% for LMG to 98% for MG in salmon spiked at the 1 ng/g level. Detection limits of 0.1 ng/g for both MG and LMG were easily obtainable using the recommended method. The operational errors, interferences, and recoveries for spiked samples compared favorably with those obtained by established methodology. The recommended method is simple, rapid, and specific for monitoring residues of MG and LMG in a number of aquatic species.     

Development and comparison of liquid–liquid extraction and accelerated solvent extraction methods for quantitative analysis of chloramphenicol,thiamphenicol, florfenicol,and florfenicol amine in poultry eggs

Accelerated solvent extraction was investigated as a novel alternative technology for the separation and quantitative analysis of chloramphenicol, thiamphenicol, florfenicol, and florfenicol amine from poultry eggs, and the results were compared with the results of liquid–liquid extraction. Rapid quantification of the target compounds was carried out by ultra‐performance liquid chromatography‐electrospray ionization tandem triple quadrupole mass spectrometry. This optimized method was validated according to the requirements defined by the European Union and the United States Food and Drug Administration. Finally, the new approach was successfully applied to the quantitative determination of these analytes in 90 commercial poultry eggs from local supermarkets.     

改良的QuEChERS与HPLC-HESI/MS/MS同时测定中华鳖组织中氯硝柳胺和酰胺醇类药物及其代谢物的残留量

建立了中华鳖(Trionyx sinensis)组织(血浆、肌肉、裙边、肝脏和肾脏)中氯硝柳胺、氯霉素、甲砜霉素、氟苯尼考和氟苯尼考胺同时测定的高效液相色谱-加热电喷雾电离源串联质谱法(HPLC-HESI/MS/MS)。样品经改进的QuEChERS方法提取净化,以氨化乙腈为提取剂,十八烷基硅烷键合硅胶(C18)粉为净化剂,甲醇-水为流动相,流速为0.3 mL/min,以Waters Symmetry~ C_(18)(2.1 mm×100 mm,3.5μm)为色谱分离柱,采用正负离子分段扫描和多反应监测模式(MRM)检测。氯霉素、甲砜霉素、氟苯尼考和氟苯尼考胺采用内标标准曲线法定量,氯硝柳胺采用基质匹配标准曲线外标法定量。结果表明,在0.3~100μg/L范围内,5种待测物均呈良好的线性关系,相关系数(r2)均不小于0.998 7。在1~20μg/kg加标水平下,中华鳖空白血浆、肌肉、裙边、肝脏和肾脏的加标回收率为77.9%~105.3%(n=6),相对标准偏差为2.7%~10.5%(n=6),方法的检出限分别为0.5、0.1、0.5、0.5、0.5μg/kg,定量下限分别为1.0、0.3、1.0、1.0、1.0μg/kg。该方法操作简便、准确、灵敏度高,适用于中华鳖组织中氯硝柳胺、氯霉素、甲砜霉素、氟苯尼考和氟苯尼考胺残留量的同时测定。     

An Indirect Competitive Enzyme-linked Immunosorbent Assay for Simultaneous Determination of Florfenicol and Thiamphenicol in Animal Meat and Urine

A high-affinity polyclonal antibody was prepared by immunizing animals with haptens FFD and FFM. Under the optimal combination of coating antigen and antibody, an indirect competitive enzyme-linked immunosorbent assay (icELISA) for simultaneous detection of florfenicol and thiamphenicol residues in animal meat and urine samples was developed. The icELISA showed an IC₅₀ value of 1.32 ng mL^?1 for florfenicol and 2.13 ng mL^?1 for thiamphenicol, respectively. The linear ranges were from 0.31 to 5.61 ng mL^?1 with a limit of detection of 0.12 ng mL^?1 for florfenicol, and 0.41 to 11.2 ng mL^?1 with a limit of detection of 0.15 ng mL^?1 for thiamphenicol, respectively. The average recoveries of florfenicol and thiamphenicol in spiked samples ranged from 77.2% to 116.0% with a relative standard deviation of less than 15%. Therefore, this proposed icELISA provided a valid detection method for florfenicol and thiamphenicol residues in animal tissue and urine samples.     

Simultaneous determination of florfenicol and florfenicol amine in fish, shrimp, and swine muscle by gas chromatography with a microcell electron capture detector

A rapid and sensitive gas chromatography method was developed for the simultaneous determination of florfenicol (FF) and its metabolite florfenicol amine (FFA) in fish, shrimp, and swine muscle. The extracted samples were defatted with hexane and cleaned up by solid-phase extraction using Oasis MCX cartridges. The eluate was evaporated to dryness, and residues were derivatized and determined by gas chromatography with a microcell electron capture detector. Overall average recoveries ranged from 81.7 to 109.7% for fish, 94.1 to 103.4% for shrimp, and 71.5 to 91.4% for swine muscle. The detection limit was 0.5 ng/g for FF and 1 ng/g for FFA, respectively. The method was validated for the determination of incurred swine muscle samples in an actual residue study.     

Specific features of amphenicol determination in foodstuffs by HPLC/high resolution quadrupole time-of-flight mass spectrometry

simple method of sample preparation, identification, and determination of amphenicols in foodstuffs (chloramphenicol, chloramphenicol succinate, thiamphenicol, thiamphenicol glycinate acetylcysteinate, florfenicol, florfenicol amine) via high-performance liquid chromatography/high resolution quadrupole time-of-flight mass spectrometry by the exact masses of the ion that form in electrospray is proposed. The objects of analysis are meat (beef, pork, poultry), meat by-products, milk and dairy products, honey, and aquaculture products. Sample preparation consisted of extraction of the target components by acetonitrile and dilution of the extract twice with deionized water. Specific features in the determination of amphenicols and their derivatives associated with the emergence of various adducts in the electrospray device in the detection of both positive and negative ions were considered. A method of amphenicol determination by the addition method is proposed; it uses the summation of area signals of all registered adducts. The features and benefits of utilizing the method of standard additions are presented. The ranges of the defined contents are 0.1–10 ng/g for chloramphenicol and 1–100 ng/g for thiamphenicol and florfenicol. The relative standard deviation of the test results did not exceed 0.1; the duration of the analysis was 30–40 min.     

Determination of clenbuterol, salbutamol, and cimaterol in bovine retina by electrospray ionization-liquid chromatography-tandem mass spectrometry

An electrospray ionization-liquid chromatography-tandem mass spectrometry (ESI/LC/MS/MS) method was developed for the simultaneous determination of the beta-agonists clenbuterol, salbutamol, and cimaterol in bovine retina. The tissue was homogenized in alkaline buffer and spiked to give 10, 15, and 20 ng/g each of the 3 analytes together with the internal standards d6-salbutamol and d6-clenbuterol. The mixture was incubated with protease enzyme to release any protein-bound analytes and then made alkaline before extraction with isobutanol. The extract was dissolved in water and transferred to a clenbuterol immunoaffinity column. After washing, the analytes were eluted and analyzed by ESI/LC/MS/MS using a C18 column with acetic acid-methanol as mobile phase. No interferences were observed from the spiked retina extract at the various single-reaction monitoring modes. Average recoveries for clenbuterol, salbutamol, and cimaterol were 94, 85, and 87% with coefficients of variation (CVs) of 9.4, 9.9, and 8.6%, respectively. A correlation coefficient of r2 = 0.9999 was obtained for all analytes. The limits of detection for clenbuterol, salbutamol, and cimaterol, determined from 3 times the standard deviation of 7 replicates of the lowest spike, were 2.5, 3.5, and 2.0 ng/g with CVs of 8.9, 11.6, and 7.2%, respectively.     

肉食品中常见4种抗生素残留的高效液相色谱分析

建立了同时测定肉食品中泰乐菌素、替米考星、氯霉素、氟苯尼考的高效液相色谱方法,样品经乙腈提取,正己烷脱脂, HLB小柱净化后,以C18反相色谱柱为分离柱,甲醇－磷酸二氢钠缓冲溶液(pH 3.0,含体积比为10％的甲醇溶液）为流动相进行梯度洗脱,检测波长λ为275 nm.泰乐菌素、替米考星、氯霉素、氟苯尼考的线性范围是0.1～20.0 mg/L,相关系数分别为0.9987、0.9992、0.9985、0.9970.其平均回收率为75％～87%,相对标准偏差为1.35％～5.41％,泰乐菌素、替米考星、氯霉素、氟苯尼考的检出限分别为20、32、19、16μg/kg.方法满足肉食品中泰乐菌素、替米考星、氯霉素、氟苯尼考的残留量测定.     

Simultaneous determination of florfenicol with its metabolite based on modified quick,easy, cheap,effective, rugged,and safe sample pretreatment and evaluation of their degradation behavior in agricultural soils

A simple and simultaneous method for the determination of florfenicol and its metabolite florfenicol amine in agricultural soils using modified quick, easy, cheap, effective, rugged, and safe sample pretreatment and reversed‐phase high‐performance liquid chromatography with tandem mass spectrometry is presented. Florfenicol and its metabolite florfenicol amine residues in agricultural soils were extracted with alkalized acetonitrile and an aliquot was cleaned up with Si(CH₂)₃NH (CH₂)₂NH₂ and C₁₈ sorbent, which were powder materials. High‐performance liquid chromatography with tandem mass spectrometry was applied to simultaneously determine the level of florfenicol and florfenicol amine in agricultural soils. Excellent linearity was achieved for florfenicol and florfenicol amine over a range of concentrations from 0.1–500 μg/L with coefficients more than 0.99. Average recoveries at four different levels (0.005, 0.05, 0.5, and 5.0 mg/kg) for florfenicol and florfenicol amine ranged from 73.6–94.9% with relative standard deviations of 2.9–12.5%. The limits of detection for florfenicol and florfenicol amine in agricultural soils were 2.0 μg/kg, and the limits of quantification were 6.0 μg/kg. Based on this method, the degradation behavior of florfenicol and its metabolite florfenicol amine in three soils (Nanchang, Hangzhou, and Changchun) under sterilized and native conditions was investigated and the transformation rate of florfenicol amine from florfenicol was evaluated.     

液相色谱-串联质谱法同时测定动物血浆中21种霉菌毒素或其代谢物残留

建立了同时检测动物血浆中黄曲霉毒素B1等21种霉菌毒素或其代谢物残留的液相色谱-串联质谱方法.动物血浆样品中加入0.1％甲酸-乙腈溶液、NaCl和无水MgSO4进行萃取,无水MgSO4和C18,PSA,A-AL对提取液进行脱水净化,经浓缩、复溶和离心后,再进行测定.采用反相C18色谱柱分离,以0.1％甲酸-0.5 mmol/L乙酸铵溶液和0.1％甲酸-甲醇溶液作为流动相进行梯度洗脱,采用电喷雾离子源(ESI)多反应监测离子模式(MRM)进行检测,基质标准曲线外标法进行定量分析,线性范围在0.05 ～ 100 ng/mL之间,方法的定量限为0.05 ～0.5 ng/mL.在高、中、低3个添加浓度水平下,21种霉菌毒素的平均回收率为62.0％ ～ 116.4％,相对标准偏差小于19％.     

分散液相微萃取/液相色谱串联质谱法快速测定猪尿中的盐酸克伦特罗与氯霉素

采用分散液相微萃取净化技术,建立了快速测定猪尿中盐酸克伦特罗和氯霉素残留的高效液相色谱-串联质谱分析方法.取5 mL猪尿样品,分别加入5 ngD9-盐酸克伦特罗和D5-氯霉素内标,调节pH至10.0,加入10％ NaC1,经250 μL三氯甲烷和750 μL异丙醇分散萃取后离心,转移下层沉淀,氮吹后以甲醇水溶液定容,采...     

Determination of chloramphenicol residues in milk, eggs, and tissues by liquid chromatography/mass spectrometry

A new liquid chromatography/mass spectrometry (LC/MS) method is presented for the determination of chloramphenicol (CAP) residues in milk, eggs, chicken muscle and liver, and beef muscle and kidney. CAP is extracted from the samples with acetonitrile and defatted with hexane. The acetonitrile extracts are then evaporated, and residues are reconstituted in 10mM ammonium acetate--acetonitrile mobile phase and injected into the LC system. CAP is determined by reversed-phase chromatography using an Inertsil ODS-2 column and MS detection with negative ion electrospray ionization. Calibration curves were linear between 0.5-5.0 ng/g for all matrixes studied. The relative standard deviations for measurements by this method were generally <12%, and average recoveries ranged from 80 to 120%, depending on the matrix involved. The method detection limits of CAP ranged from 0.2 to 0.6 ng/g, which are comparable to previously reported results. The proposed method is rapid, simple, and specific, allowing a single analyst to easily prepare over 40 samples in a regular working day.     

Determination of chloramphenicol in aquatic products by graphene‐based SPE coupled with HPLC‐MS/MS

An effective analytical protocol using graphene‐based SPE coupled with HPLC‐MS/MS for determination of chloramphenicol (CAP) in aquatic products has been developed. In the present work, graphene was evaluated as SPE sorbents for the analytes enrichment and clean up. The target analytes were quantified by a triple‐quadrupole linear ion trap MS in multiple‐reaction monitoring mode. In addition, the proposed method was validated according to Commission Decision 2002/657/EC. The calibration curve was linear over the range of 0.5–100 ng/mL. The mean values of RSD of intra‐ and interday ranging from 1.48 to 4.29% and from 3.25 to 7.42% were obtained, respectively. In the three fortified levels, the recoveries of CAP ranging from 92.3 to 103.4% with RSDs ≤ 5.58% were obtained. The proposed method has been successfully applied to the analysis of CAP in several aquatic product samples, indicating that graphene was a potential SPE sorbent for the enrichment of trace residues in food samples.     

A rapid and easy multiresidue method for the determination of pesticide residues in vegetables, fruits, and cereals using liquid Chromatography/tandem mass spectrometry

The applicability of a rapid and easy multiresidue method for determination of pesticide residues in agricultural products by using liquid chromatography/tandem mass spectrometry (LC/MS/MS) was examined. Pesticide residues were extracted with acetonitrile in a disposable tube using a homogenizer, followed by salting out with anhydrous magnesium sulfate and sodium chloride. The extract was purified with a double-layered cartridge column (graphite carbon black/primary-secondary amine silica gel). After removal of the solvent, the extract was resolved in methanol-water and analyzed with LC/MS/MS. Recovery tests of 99 pesticide residues from 7 agricultural products were performed at 20 and 100 ng/g. Throughout all of the agricultural products tested, 47 pesticides exhibited satisfactory recoveries (70-120%) and relative standard deviations (<20%) at both concentrations. The time for processing of 12 samples to test solutions was approximately 2-3 h. This method could be useful for determination of pesticide residues in agricultural products.     

Rapid determination of chloramphenicol residues in aquaculture tissues by immunochromatographic assay.

An immunochromatographic assay was developed to detect chloramphenicol (CAP) residues in aquaculture tissues. The limit of detection (LOD) was 10 ng g(-1) for detecting CAP spiked in the aquaculture tissues. The results were confirmed by liquid chromatography tandem mass spectrometry (LC/MS/MS) and indicated that there was a good agreement between the two methods. The linear regression equation was y = 1.19x + 0.539 with R(2) = 0.978. The assay time for test was less than 5 min and the method is suitable for rapid testing on-site.     

Determination of terbinafine (Lamisil) in human hair by microbore liquid chromatography/tandem mass spectrometry

An analytical method for the determination of terbinafine (Lamisil(R)) in human hair was developed and validated. Human hair (10 mg) was hydrolyzed in 0.50 mL of 5.0 N sodium hydroxide for 1.5 h. The aqueous layer was extracted with 1.5 mL of n-hexane. The organic layer was separated and re-extracted with 0.20 mL of formic acid (12.5%)/2-propanol (85:15, v/v). The aqueous layer was separated and 0.010 mL of the aqueous extract was injected onto a reversed-phase microbore (50 x 1.0 mm i.d.) column for analysis by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The instrument was equipped with an electrospray ionization (ESI) interface and operated in the positive ion mode of detection. Interday and intraday accuracy and precision were assessed from the relative recoveries of spiked samples analyzed on three different days. The method showed excellent specificity and ruggedness with a lower limit of quantitation of 10 ng/g (i.e., 10 ppb) using 10 mg of human hair.     

超高效液相色谱-质谱联用检测 土壤中两种抗生素呋喃唑酮和氟苯尼考

建立了超高效液相色谱-串联质谱(UPLC/MS/MS)检测土壤中多种环境基质下呋喃唑酮和氟苯尼考的方法.提取液采用磷酸盐缓冲溶液(pH=3)-乙腈(3:7,V/V),经过SPE固相萃取小柱SAX-HLB串联富集,使用Waters BEH C18色谱柱(2.1×100 mm)进行分离,UPLC/MS/MS在多反应监测模式下进行定性与定量分析.以3倍信噪比确定方法检出限,以10倍信噪比确定方法定量限.结果表明,本方法在5 min内即可分离两种物质,呋喃唑酮和氟苯尼考的检出限分别为1.19和0.41μg/kg;定量限分别为3.40和1.37μg/kg.50μg/L加标水平的呋喃唑酮和氟苯尼考的回收率分别为92%和79%;200μg/L加标水平下呋喃唑酮与氟苯尼考的回收率分别为96%和86%.     

Fast and selective extraction of chloramphenicol from soil by matrix solid‐phase dispersion using molecularly imprinted polymer as dispersant

The molecularly imprinted polymer (MIP) was synthesized and used as dispersant of matrix solid‐phase dispersion (MSPD) for the extraction of chloramphenicol (CAP) in soil samples. The satisfactory recovery of CAP was obtained by the optimized extraction conditions: 1:2 as the ratio of sample to MIPs; 5 min as the dispersion time; 30% aqueous methanol as washing solvent and methanol as elution solvent. The CAP extracted from soil was determined by LC‐MS/MS. The slight ion suppression phenomenon was observed for the CAP when the sample was cleaned up by MSPD with MIP as dispersant, when compared with C18 as MSPD dispersant, which caused significant ion suppression. LOD of CAP is 4.1 ng/g. RSDs of intra‐ and inter‐day tests ranging from 3.1 to 6.2% and from 3.9 to 8.3% are obtained. At all three fortified levels (20, 100 and 500 ng/g), recoveries of CAP are in the range of 86.9–92.6%. The effect of ageing time of spiked soil sample on the CAP recovery was examined. The CAP recovery decreased from 91.0 to 36.9% when the ageing time changed from 1 day to 4 wk.