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1.
A liquid chromatography (LC) method is presented for the quantitative determination of malachite green (MG) in salmon. MG and leucomalachite green (LMG) residues were extracted from salmon tissue with ammonium acetate buffer and acetonitrile, and then isolated by partitioning into dichloromethane. LMG was quantitatively oxidized to the chromic MG by reaction with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. Samples were then cleaned up by solid-phase extraction with alumina and propylsulfonic acid phases. Extracts were analyzed for MG by LC with visible detection at 618 nm using isocratic elution and a C18 column. The method was validated in 35 farm-raised salmon (Salmo salar) tissues fortified at 1, 2, 4, and 10 ng/g (ppb) with an average recovery of 95.4% and a relative standard deviation of +/- 11.1%, and in 5 canned salmon (Oncorhynchus gorbuscha) samples fortified at 10 ng/g with an average recovery of 88.9 +/- 2.6%. This study also included the determination of MG and LMG residues in tissues from salmon that had been treated with MG MG was quantitatively determined at the method detection limit of 1 ng/g.  相似文献   

2.
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.  相似文献   

3.
A method has been developed to analyse for malachite green (MG), leucomalachite green (LMG), crystal violet (CV) and leucocrystal violet (LCV) residues in salmon. Salmon samples were extracted with acetonitrile:McIIIvain pH 3 buffer (90:10 v/v), sample extracts were purified on a Bakerbond strong cation exchange solid phase extraction cartridge. Aliquots of the extracts were analysed by LC-MS/MS. The method was validated in salmon, according to the criteria defined in Commission Decision 2002/657/EC. The decision limit (CCalpha) was 0.17, 0.15, 0.35 and 0.17 microg kg(-1), respectively, for MG, LMG, CV and LCV and for the detection capability (CCbeta) values of 0.30, 0.35, 0.80 and 0.32 microg kg(-1), respectively, were obtained. Fortifying salmon samples (n=6) in three separate assays, show the accuracy to be between 77 and 113% for MG, LMG, LCV and CV. The precision of the method, expressed as RSD values for the within-laboratory reproducibility, for MG, LMG and LCV at the three levels of fortification (1, 1.5 and 2.0 microg kg(-1)), was less than 13%. For CV a more variable precision was obtained, with RSD values ranging between 20 and 25%.  相似文献   

4.
A sensitive method for the determination and confirmation of the sum of malachite green (MG) and leucomalachite green (LMG) in salmon muscle has been developed. It is based on the use of an oxidative pre-column reaction which converts LMG into MG previous to liquid chromatography-atmospheric pressure chemical ionisation-mass spectrometry (LC-APCI-MS) analysis. The determination of both compounds together constitutes a good screening method to confirm the presence of this kind of residue, taking into account that the combined signals will provide a gain of sensitivity. The detection limit, determined for spiked salmon samples using the confirmatory ion m/z 313, was 0.15 microg/kg. The recoveries determined at a spiking level of 2 microg/kg were 85 and 70% for LMG and MG, respectively, with respective relative standard deviations of 1.3 and 3.1%.  相似文献   

5.
This paper describes the development of an analytical procedure to determine malachite green (MG) residues in salmon samples using molecularly imprinted polymers (MIPs) as the extraction and clean-up material, followed by liquid chromatography-linear ion trap mass spectrometry (LC-QqQLIT-MS/MS). MG and two structurally related compounds, crystal violet (CV) and brilliant green (BG) were employed for the selectivity test. The imprinted polymers exhibited high binding affinity for MG, while CV and BG showed less binding capacity: 47% and 34%, respectively. The recovery values of MG in salmon samples fortified with leucomalachite green (LMG) were determined by measuring the amount of MG in the sample, after carrying out the oxidation reaction with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), which converts the LMG back into chromic-form. The average recovery of MG in spiked salmon muscle over the concentration range 1-100 ng g−1 was 98% with a relative standard deviation value (R.S.D.) below 12%. The method detection limits (MDLs) obtained for MG, CV, BG and their leuco-metabolites were in the range of 3-20 ng kg−1 (ppt).  相似文献   

6.
A simple method using LC/MS/MS was developed and validated to determine residues of malachite green (MG) and leucomalachite green (LMG) in fish fillet. A modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) technique was used to perform the sample preparation. The optimal extraction and cleanup conditions were established using an experimental design. The validation parameters obtained to determine both MG and LMG complied with the requirements established by regulatory agencies for the presence of such substances in fish, which establish that the method must attain, at least, a minimum required performance limit of 2 ng/g. The accuracy values ranged between 95 and 107%, and the precision values were lower than 11.2%. The method was used in the analysis of tilapia samples (n = 20) commercialized in Campinas, SP, Brazil. None of the samples presented detectable levels of MG or LMG residues.  相似文献   

7.
A multi-residue LC/MS method has been developed to confirm avermectin drug residues in several food matrices. Ivermectin (IVR), doramectin (DOR), eprinomectin (EPR) and moxidectin (MOX) are confirmed using atmospheric pressure chemical ionization (APCI) with negative ion detection and selected ion monitoring of three to four ions for each compound. The drug residues are extracted from tissue or milk using previously published procedures. IVR and DOR are confirmed at 20 ppb levels in fortified salmon muscle; IVR is also confirmed in tissue from salmon dosed with the drug. Residues of DOR, IVR, and EPR are confirmed in fortified milk at the 20 ppb level and in fortified beef liver at 40 ppb. Residues of MOX can also be confirmed in these matrices, but at slightly higher levels (40-80 ppb).  相似文献   

8.
A liquid chromatographic (LC) multiresidue screening procedure was developed for determination of eprinomectin, moxidectin, abamectin, doramectin, and ivermectin in beef liver at 0, 25, 50, and 100 ppb levels. A procedure using low resolution LC/atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) was developed with further purification steps added to the quantitative LC method to confirm residues. Acetonitrile extracts of liver, prior to derivatization for LC analysis, were further purified by using a C8 solid-phase extraction cartridge and an alumina-B cartridge. The purified extract was analyzed by injection into an LC/positive ion APCI MS. Identity of the compound was confirmed by comparison of its retention time and relative intensity data with those of a standard or recovery from a fortified control liver sample. Anthelmintic drugs in acetonitrile extracts of liver containing eprinomectin, moxidectin, abamectin, doramectin, and ivermectin at 25 ppb, the lowest level of fortification used in the LC determinative method, were successfully confirmed.  相似文献   

9.
A method has been developed for the simultaneous determination of malachite green, gentian violet and their leuco-metabolites in various aquatic products using isotope dilution liquid chromatography-linear ion trap mass spectrometry without post-column oxidation. Sample was extracted with McIlvaine buffer and acetonitrile, followed by partitioning with dichloromethane, purified on basic alumina and OASIS MCX SPE column, and finally analyzed by LC-ESI-MS/MS with the select reaction monitoring (SRM) mode. Decision limits (CCalpha, alpha=0.01) and detection capability (CCbeta, beta=0.05) of the method were in the range of 0.02-0.09 and 0.04-0.13microg/kg for MG, GV, LMG and LGV in grass carp, eel, salmon, shrimp and shellfish, respectively, recoveries of MG, GV, LMG and LGV at all fortification levels (0.25-10microg/kg) were from 80.8% to 115.7%, inter-day relative standard derivations were from 1.9% to 18.4%. This method appeared suitable for the control of MG, GV, LMG and LGV residues in aquatic products.  相似文献   

10.
The effects of various cooking methods (boiling, baking and microwaving) on residues of malachite green (MG) and its major metabolite, leucomalachite green (LMG), in incurred carp muscles were investigated. Moreover, the stability of MG and LMG standard solutions under boiling in water and in oil was examined. The MG and LMG residues in cooked meat were determined by liquid chromatography with visible and fluorescence detectors. The results showed that in muscles cooked by boiling or baking MG concentration was reduced by 54% in 15 min while LMG was stable in these conditions. By microwave cooking MG residues were reduced by 61% after 1 min. Microwaving was the only method of cooking when a loss of LMG was observed (40% in 1 min). Both MG and LMG standard solutions were stable in boiling water at 100 degrees C. In cooking oil, MG was reduced by 49% after 10 min and less than 3% of the original MG remains after 90 min at 150 degrees C. No losses of LMG were observed over a time period of 120 min in cooking oil at 150 degrees C. Upon increasing the temperature to 210 degrees C and holding for 120 min, MG was rapidly reduced by 97% after 10 min. LMG under the same conditions was reduced by 18% after 10 min. No further loses of MG and LMG were observed after 120 min. The findings of this investigation show that the high temperature does not guarantee a full breakdown of residue of MG and LMG which may occur in carp muscles.  相似文献   

11.
Alternative ionization methods are increasingly being utilized to increase the versatility and selectivity of liquid chromatography/mass spectrometry (LC/MS). One such technique is the practice of using commercially available atmospheric pressure chemical ionization (APCI) sources with the corona discharge turned off, a process termed no-discharge APCI (ND-APCI). The relative LC/MS responses for several different classes of veterinary drugs were obtained by using ND-APCI, electrospray ionization (ESI), and APCI. While the ND-APCI-MS and -MSn spectra for these compounds were comparable with ESI, ND-APCI provided advantages in sensitivity and selectivity for some compounds. Drugs that were charged in solution as cations or sodium adducts responded particularly well with this technique. Instrumental parameters such as temperatures, gas and liquid flow rates, and source design were investigated to determine their effect on the process of ND-APCI. This paper explores advantages of using ND-APCI for the determination and confirmation of drug residues that might be found in food matrices, including malachite green residues in fish tissue and avermectin residues in milk.  相似文献   

12.
吴文伟  王翌  刘可鑫  李天松  杨咏洁 《色谱》2020,38(11):1332-1339
研究以双特异性核酸适配体A3作为传感探针、纳米金(AuNPs)为指示剂、NaCl溶液为聚集诱导剂,构建了一种新型的免标记AuNPs比色生物传感器,可实现水产品中孔雀石绿(MG)和无色孔雀石绿(LMG)的同步、快速、可视化检测。该方法的检测原理是核酸适配体A3对MG和LMG有双特异性识别能力,可作为MG和LMG理想的识别受体。它可通过静电作用吸附到AuNPs表面,保护AuNPs并抑制高盐溶液诱导的聚集,AuNPs溶液颜色不变,即为红色;当加入靶标MG或LMG后,该核酸适配体能够与靶标特异性结合,并从AuNPs表面上解离,AuNPs失去保护作用而在高盐溶液诱导下发生聚集,溶液颜色由红变蓝。根据颜色变化,可通过肉眼定性或通过光谱仪定量分析MG和LMG的残留量。该方法首先将50 μL的核酸适配体A3(终浓度150 nmol/L)与150 μL的AuNPs(终浓度1.25 nmol/L)混合,室温孵育6 min。随后加入50 μL待测液,室温孵育30 min。最后加入50 μL NaCl(终浓度150 mmol/L),4 min后观察溶液颜色变化,并分别测定MG和LMG在520 nm和650 nm下的吸光度值。结果表明,在最佳反应条件下,该方法能够特异性检测MG和LMG,而对磺胺嘧啶(SDZ)和硝基呋喃妥因(NFT)无交叉反应;当MG、LMG的浓度为0~17.5 μmol/L时,吸光度比值与靶标浓度呈现良好的线性关系,相关系数(R 2 )分别为0.9938和0.9715。MG和LMG的检出限分别为6.93 nmol/L和6.38 nmol/L,加标回收率分别为88.60%~93.30%和101.80%~107.00%,相对标准偏差(RSD)分别为2.27%~3.55%和2.62%~3.75%。该方法操作简单,快速和灵敏,可为水产品中MG和LMG的同步快速检测提供一种新方法。  相似文献   

13.
A liquid chromatography (LC) method is described for the determination of oxytetracycline (OTC) in farmed Atlantic salmon muscle tissue. The method involves homogenization of salmon tissue, extraction of OTC into Mcllvaine-EDTA buffer, acid precipitation of proteins, cleanup through tandem solid-phase extraction cartridges (Strata-X and aminopropyl), elution with mobile phase containing slightly alkaline buffer and Mg2+, and LC separation with metal-chelate induced fluorescence detection. Salmon tissue was fortified with 0.10, 0.25, 0.50, 0.75, and 1.0 microg/g (ppm) oxytetracycline. Average absolute recoveries were 84, 76, 70, 76, and 85%, respectively, with relative standard deviation (RSD) values all less than 9%. The interassay average recovery was 78%, with a 4.2% RSD. Determination was based on a standard graph using peak areas with standard solutions equivalent to 0.0625, 0.125, 0.25, 0.50, and 1.0 ppm in tissue. A set of 5 matrix controls (unfortified salmon tissue) were also analyzed, in which no OTC was detected. The lowest standard was used as the limit of quantitation.  相似文献   

14.
A simple and highly sensitive LC/MS method was developed for the simultaneous determination of six ionophores--lasalocid, monensin, laidlomycin, maduramycin, salinomycin, and narasin--in feed. The procedure involved extraction of 1 g of feed with 4 mL of methanol-water (9 + 1, v/v) by shaking on a platform shaker for 45 min. After centrifugation, the extracts were diluted with methanol-water (75 + 25, v/v) and analyzed without any cleanup. The analysis was performed on a Betasil C18 column (150 x 4.6 mm id, 5 pm particle size) connected to an LC/MS system operated in the atmospheric pressure chemical ionization (APCI) mode. We believe this to be the first method that uses the APCI mode for the analysis of ionophores. The mobile phase consisted of 50 mM ammonium acetate as solvent A and acetonitrile-methanol (7 + 3, v/v) as solvent B in a gradient run. Excellent recoveries of 81-120% were found for all compounds at fortification levels of 1-200 microg/g, with RSD < or =15% (except 17% for maduramycin at 2 and 5 microg/g, and 16% for salinomycin at 1 microg/g). At 0.5 microg/g, recoveries of 87-119% were obtained, with RSD < or =20%. However, recovery of lasalocid was 133% and salinomycin 79% in sow and horse feed, respectively. Average RSD values of lasalocid and salinomycin were 22 and 21%, respectively. Finally, proficiency test samples analyzed with the method demonstrated favorable agreement with the certified values.  相似文献   

15.
Liquid chromatography with time-of-flight mass spectrometry (LC-TOF-MS) method has been developed for simultaneous confirmation by accurate mass measurement and quantitative determination of antibiotics (enrofloxacin, oxolinic acid, flumequine, erythromycin), fungicides (malachite green MG, leucomalachite green LMG) and parasiticide (emamectin benzoate) residues in edible portion of salmon. Confirmation of chemotherapeutant residues has been based on the system of identification points (IPs) established in the Commission Decision 2002/657/EC concerning the use of mass spectrometry (MS) techniques. A validation study on matrix is presented evaluating accuracy in terms of precision (λppm 0.83-1.15) and trueness (0.22-0.70 Da). Limits of detection (LODs) and limits of quantification (LOQs) were in ranges of 1-3 and 3-9 μg/kg, below the maximum residue limits (MRLs) established in current EU legislation (100-200 μg/kg) for these chemotherapeutants. Considering the EU guidelines, decision limits (CCα) and detection capabilities (CCβ) were determined (ranges of 103-218 and 107-234 μg/kg, respectively) for authorised substances. For no authorised compounds (MG and LMG), LODs were 2 and 1 μg/kg, respectively, but exceed the MRPL (minimum required performance limit) established in the legislation which corresponds to the sum of MG and LMG (2 μg/kg). Acceptable intra-day and inter-day variability, in terms of relative standard deviation (R.S.D.) of the analytical method, were obtained (2-15%). Linearity was demonstrated from the LOQs of the analytes to 600 μg/kg (r > 0.9991). The method has involved an extraction procedure based on solid-liquid extraction (SLE) with recoveries higher than 80% for most target chemotherapeutants, with exception of enrofloxacin (40%).  相似文献   

16.
This paper reports the properties and advantages of the three-way calibration models based on parallel factor analysis (PARAFAC) in the simultaneous determination of malachite green (MG) and its metabolite (leucomalachite green, LMG) in trout. A recently method proposed by community reference laboratory AFSSA-LERMVD (Fougères, France) has been used. The method is based on liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) in multiple reaction monitoring (MRM) mode. The validation of the method has been carried out taking into account the Decision 2002/657/EC. The figures of merit for PARAFAC and univariate calibration models of six non-consecutive days analyzed during a month were evaluated. With the samples of the first 3 days, calibration models were built and the fish fortification samples of the other days were predicted. Decision limits (CCalpha, alpha=0.01), detection capabilities (CCbeta, beta=0.05) and mean relative errors in absolute value (in calibration and with test samples) obtained with PARAFAC calibrations were more homogeneous than the ones obtained with the univariate calibrations, especially in LMG. These figures of merit were in the range of 0.2-0.83 microg kg(-1) (CCbeta) and 0.2-0.49 microg kg(-1) (CCalpha), whereas mean relative errors in absolute value were in the range of 1.1-7.4% in calibration and 3-12% in test samples for MG and LMG with PARAFAC calibrations. The PARAFAC calibrations allow detecting the test samples which are not similar to the calibration samples and in this way their wrong quantification is avoided.  相似文献   

17.
Malachite green oxalate (MG oxalate) and leucomalachite green (LMG) have been prepared and certified as pure reference materials. The purities of MG oxalate and LMG were assessed by high-performance liquid chromatography–diode array detection (HPLC–DAD), nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry (DSC), Karl Fischer titration, ashing and thermogravimetric analysis (TGA). MG oxalate was purified by supercritical fluid extraction (SFE). Prior to purification, commercial MG oxalate purity was estimated to be about 90%. The main impurities present in SFE-purified MG oxalate were identified and quantified using HPLC–DAD. The main impurities were found to be monode-MG (monodemethylated MG oxalate synthesis impurity), 4-(dimethylamino)benzophenone (4-DMABP), MG-carbinol and LMG. The homogeneity of both reference materials was also determined. Issues associated with the stability of LMG and MG oxalate in solution forced an extensive study investigating different parameters i.e. solvent, acid, analyte concentration and temperature. MG oxalate (100 μg/mL) was found to be stable in acetonitrile containing 1% v/v glacial acetic acid for at least 155 days and LMG (100 μg/mL) was stable in acetonitrile for at least 133 days. The final purity value for MG oxalate was 94.3 ± 1.4% m/m at the 95% confidence interval (or 67% m/m if MG cation is reported). For LMG, the certified purity was found to be 98.8 ± 0.8% m/m at the 95% confidence interval. Figure Calibration reference materials for malachite green and leucomalachite green, certified for purity, are essential in characterising these key analytes in a fish matrix reference material  相似文献   

18.
采用超高效液相色谱-串联质谱法同时检测水产品中孔雀石绿、结晶紫及其代谢物(隐色孔雀石绿、隐色结晶紫)。经匀浆处理的水产品样品,用乙腈提取,加入酸性氧化铝去除油脂,旋转蒸发器蒸干后,用甲酸-乙腈-水(0.1+10+89.9)溶液溶解,样品溶液用超高效液相色谱分离,电喷雾串联四极杆质谱进行检测。以氘代孔雀石绿、氘代隐色孔雀石绿为内标物。孔雀石绿、结晶紫及其代谢物的质量浓度均在5.0μg·L-1以内与其峰面积呈线性关系,检出限(3S/N)在0.10~0.12μg.kg-1之间。以空白水产品样品为基体进行回收试验,方法的回收率在90.2%~108.0%之间,相对标准偏差(n=6)在2.3%~7.6%之间。  相似文献   

19.
A liquid chromatographic (LC)/mass spectrometric (MS) method was developed for determining the residues of chloramphenicol, thiamphenicol, florfenicol, and florfenicol amine in a number of aquatic species. The phenicols are extracted with acetone, the extracts are partitioned with dichloromethane, the aqueous layer is removed, and the organic layer is evaporated to dryness. The residue is dissolved in dilute acid and defatted with hexane, and the aqueous layer is prepared for analysis by LC. The phenicols are determined by reversed-phase LC by using a Hypersil C18-BD column with a water-acetonitrile gradient and MS detection using selected-ion recording. Calibration curves were linear for all analytes between 0.015 and 0.425 ng injected. The relative standard deviations for measurements by the proposed method were < 10% for all of the analytes studied, with recoveries ranging from 71% for florfenicol amine to 107% for florfenicol in salmon tissue spiked at the 2 ng/g level. Detection limits of 0.1 ng/g for florfenicol and chloramphenicol, 0.3 ng/g for thiamphenicol, and 1.0 ng/g for florfenicol amine are easily obtainable. The operational errors, interferences, and recoveries for spiked samples compare favorably with those obtained by established LC methodology. The proposed method is simple, rapid, and specific for monitoring residues of chloramphenicol, thiamphenicol, florfenicol, and florfenicol amine in a number of aquatic species.  相似文献   

20.
Current development in catalyst discovery includes combinatorial synthesis methods for the rapid generation of compound libraries combined with high-throughput performance-screening methods to determine the associated activities. Of these novel methodologies, mass spectrometry (MS) based flow chemistry methods are especially attractive due to the ability to combine sensitive detection of the formed reaction product with identification of introduced catalyst complexes. Recently, such a mass spectrometry based continuous-flow reaction detection system was utilized to screen silver-adducted ferrocenyl bidentate catalyst complexes for activity in a multicomponent synthesis of a substituted 2-imidazoline. Here, we determine the merits of different ionization approaches by studying the combination of sensitive detection of product formation in the continuous-flow system with the ability to simultaneous characterize the introduced [ferrocenyl bidentate+Ag]+ catalyst complexes. To this end, we study the ionization characteristics of electrospray ionization (ESI), atmospheric-pressure chemical ionization (APCI), no-discharge APCI, dual ESI/APCI, and dual APCI/no-discharge APCI. Finally, we investigated the application potential of the different ionization approaches by the investigation of ferrocenyl bidentate catalyst complex responses in different solvents.  相似文献   

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