The Experts below are selected from a list of 165 Experts worldwide ranked by ideXlab platform
Christoph Von Holst - One of the best experts on this subject based on the ideXlab platform.
-
determination of Semduramicin in poultry feed additive premixture and compound feed by liquid chromatography and uv spectrophotometric detection after post column derivatisation
Journal of Pharmaceutical and Biomedical Analysis, 2012Co-Authors: Ursula Vincent, Federica Serano, Maria Jose Gonzalez De La Huebra, Christoph Von HolstAbstract:A new, simple and fit for purpose method based on liquid chromatography with UV spectrophotometric detection and post-column derivatisation (LC-UV-PCD) for the determination of Semduramicin in poultry compound feed, premixtures and feed additive as well as its discrimination from other coccidiostats in poultry compound feed has been developed and single-laboratory validated. The concentration levels of the target analyte at which the validation experiments have been carried out varied between 12.8 and 51.3 mg kg(-1) in compound feed, covering the authorised levels of Semduramicin according to European Union legislation. Furthermore, the method has been validated for a premixture sample containing Semduramicin at 3 g kg(-1) and the feed additive containing Semduramicin at 51 g kg(-1). The method developed involved a simple extraction of the coccidiostats with acetonitrile from the feed samples followed by a filtration of the supernatants. The resulting supernatants were submitted to chromatographic analysis. When analysing the feed additive and the premixture samples, the extraction solution was appropriately diluted prior to LC-UV-PCD analysis. The analytes were quantified through an external calibration curve prepared with pure Semduramicin standards. The relative standard deviations for repeatability and for intermediate precision varied from 2.4 to 8.8% and from 2.6 to 8.8%, respectively, and the values for the relative recovery rate ranged from 89 to 95%. The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be below 1 mg kg(-1) and 3 mg kg(-1), respectively. Moreover, the results showed a comparable performance profile, when using methyl isobutyl ketone instead of acetonitrile as extraction solvent.Based on the obtained method performance characteristics, the method is considered suitable for the determination of Semduramicin in poultry compound feed at authorised level, in premixtures and in the feed additive, hence allowing the enforcement of the European Union legislation regarding the control and the monitoring in feedingstuffs.
-
interlaboratory comparison of an analytical method for the determination of Semduramicin in poultry feed at the authorized level using high performance liquid chromatography coupled to postcolumn derivatization and spectrophotometric detection
Journal of AOAC International, 2012Co-Authors: Maria Jose Gonzalez De La Huebra, Ursula Vincent, Federica Serano, Christoph Von HolstAbstract:The performance characteristics of a method based on HPLC with postcolumn derivatization and spectrophotometric detection for the quantification of Semduramicin in poultry feedingstuffs have been determined via a collaborative study. Semduramicin is a feed additive that is authorized for fattening chickens within the European Union at a minimum and maximum content of 20 and 25 mg/kg in feedingstuffs, respectively. The target concentration of Semduramicin in the test samples ranged from 11.5 to 45.0 mg/kg. The study has been conducted with two different types of test material, namely, feedingstuff samples that have been previously ground in our laboratory and pelleted feedingstuffs. In the latter case, the laboratories participating in the study had to grind the samples prior to analysis. The obtained RSD for repeatability (RSD(r)) ranged from 2 to 10% for the ground materials, and from 2 and 7% for the pelleted materials. The RSD for reproducibility (RSDR) varied between 11 and 16% for the ground materials, and between 12 and 15% for the pelleted materials. These data indicated that grinding as an additional step in the analytical procedure did not influence the precision profile of the method. In addition, the HorRat values for all test materials were below or equal to 1.5, thus demonstrating that the obtained precision data were acceptable for the purpose of the method. Furthermore, an estimation of trueness based on statistical treatment of the results reported from the laboratories for spiked samples revealed acceptable mean recovery values of 88 +/- 4%. Based on the obtained performance profile, the method can be considered fully validated and transferable to control laboratories to be used within the framework of official control.
-
determination of Semduramicin in poultry feed at authorized level by liquid chromatography single quadrupole mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2010Co-Authors: Maria Jose Gonzalez De La Huebra, Ursula Vincent, Christoph Von HolstAbstract:Abstract A novel liquid chromatography single quadrupole mass spectrometry (LC–MS) method for the determination of the feed additive Semduramicin, in poultry feed, was developed and single-laboratory validated. This work was selected as a real case scenario to outline the different steps that may be needed whenever the standardisation of an analytical method in the field of methods of analysis for animal feedingstuffs is attempted. In this manuscript the main achievements reached within the development and the single-laboratory validation of an analytical method for the determination of Semduramicin in feedingstuffs are detailed. Semduramicin is extracted from the feedingstuffs with acetonitrile. The obtained extracts are then filtered and diluted appropriately. The separation has been carried out in a reverse phase C18 column using isocratic elution with a mixture of methanol and 20 mM ammonium formate solution as mobile phase. The ammonium adducts have been selected for monitoring the coccidiostats signals in the mass spectrometry detector. The method has been successfully validated for the determination of Semduramicin concentrations ranging between half of the minimum authorized concentration (10 mg kg−1) to twice of the maximum authorized concentration (50 mg kg−1). A good relative standard deviation for repeatability (RSDr) varying from 2.8 to 3.2% has been obtained whereas the relative standard deviation for intermediate precision (RSDInt.) ranged from 3.7 to 7.3%. The obtained analytical performance characteristics of the method demonstrated its fitness for the purpose, making thus the proposed method suitable to be submitted for the last phase within the standardisation procedure, i.e. the inter-laboratory study.
Maria Jose Gonzalez De La Huebra - One of the best experts on this subject based on the ideXlab platform.
-
determination of Semduramicin in poultry feed additive premixture and compound feed by liquid chromatography and uv spectrophotometric detection after post column derivatisation
Journal of Pharmaceutical and Biomedical Analysis, 2012Co-Authors: Ursula Vincent, Federica Serano, Maria Jose Gonzalez De La Huebra, Christoph Von HolstAbstract:A new, simple and fit for purpose method based on liquid chromatography with UV spectrophotometric detection and post-column derivatisation (LC-UV-PCD) for the determination of Semduramicin in poultry compound feed, premixtures and feed additive as well as its discrimination from other coccidiostats in poultry compound feed has been developed and single-laboratory validated. The concentration levels of the target analyte at which the validation experiments have been carried out varied between 12.8 and 51.3 mg kg(-1) in compound feed, covering the authorised levels of Semduramicin according to European Union legislation. Furthermore, the method has been validated for a premixture sample containing Semduramicin at 3 g kg(-1) and the feed additive containing Semduramicin at 51 g kg(-1). The method developed involved a simple extraction of the coccidiostats with acetonitrile from the feed samples followed by a filtration of the supernatants. The resulting supernatants were submitted to chromatographic analysis. When analysing the feed additive and the premixture samples, the extraction solution was appropriately diluted prior to LC-UV-PCD analysis. The analytes were quantified through an external calibration curve prepared with pure Semduramicin standards. The relative standard deviations for repeatability and for intermediate precision varied from 2.4 to 8.8% and from 2.6 to 8.8%, respectively, and the values for the relative recovery rate ranged from 89 to 95%. The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be below 1 mg kg(-1) and 3 mg kg(-1), respectively. Moreover, the results showed a comparable performance profile, when using methyl isobutyl ketone instead of acetonitrile as extraction solvent.Based on the obtained method performance characteristics, the method is considered suitable for the determination of Semduramicin in poultry compound feed at authorised level, in premixtures and in the feed additive, hence allowing the enforcement of the European Union legislation regarding the control and the monitoring in feedingstuffs.
-
interlaboratory comparison of an analytical method for the determination of Semduramicin in poultry feed at the authorized level using high performance liquid chromatography coupled to postcolumn derivatization and spectrophotometric detection
Journal of AOAC International, 2012Co-Authors: Maria Jose Gonzalez De La Huebra, Ursula Vincent, Federica Serano, Christoph Von HolstAbstract:The performance characteristics of a method based on HPLC with postcolumn derivatization and spectrophotometric detection for the quantification of Semduramicin in poultry feedingstuffs have been determined via a collaborative study. Semduramicin is a feed additive that is authorized for fattening chickens within the European Union at a minimum and maximum content of 20 and 25 mg/kg in feedingstuffs, respectively. The target concentration of Semduramicin in the test samples ranged from 11.5 to 45.0 mg/kg. The study has been conducted with two different types of test material, namely, feedingstuff samples that have been previously ground in our laboratory and pelleted feedingstuffs. In the latter case, the laboratories participating in the study had to grind the samples prior to analysis. The obtained RSD for repeatability (RSD(r)) ranged from 2 to 10% for the ground materials, and from 2 and 7% for the pelleted materials. The RSD for reproducibility (RSDR) varied between 11 and 16% for the ground materials, and between 12 and 15% for the pelleted materials. These data indicated that grinding as an additional step in the analytical procedure did not influence the precision profile of the method. In addition, the HorRat values for all test materials were below or equal to 1.5, thus demonstrating that the obtained precision data were acceptable for the purpose of the method. Furthermore, an estimation of trueness based on statistical treatment of the results reported from the laboratories for spiked samples revealed acceptable mean recovery values of 88 +/- 4%. Based on the obtained performance profile, the method can be considered fully validated and transferable to control laboratories to be used within the framework of official control.
-
determination of Semduramicin in poultry feed at authorized level by liquid chromatography single quadrupole mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2010Co-Authors: Maria Jose Gonzalez De La Huebra, Ursula Vincent, Christoph Von HolstAbstract:Abstract A novel liquid chromatography single quadrupole mass spectrometry (LC–MS) method for the determination of the feed additive Semduramicin, in poultry feed, was developed and single-laboratory validated. This work was selected as a real case scenario to outline the different steps that may be needed whenever the standardisation of an analytical method in the field of methods of analysis for animal feedingstuffs is attempted. In this manuscript the main achievements reached within the development and the single-laboratory validation of an analytical method for the determination of Semduramicin in feedingstuffs are detailed. Semduramicin is extracted from the feedingstuffs with acetonitrile. The obtained extracts are then filtered and diluted appropriately. The separation has been carried out in a reverse phase C18 column using isocratic elution with a mixture of methanol and 20 mM ammonium formate solution as mobile phase. The ammonium adducts have been selected for monitoring the coccidiostats signals in the mass spectrometry detector. The method has been successfully validated for the determination of Semduramicin concentrations ranging between half of the minimum authorized concentration (10 mg kg−1) to twice of the maximum authorized concentration (50 mg kg−1). A good relative standard deviation for repeatability (RSDr) varying from 2.8 to 3.2% has been obtained whereas the relative standard deviation for intermediate precision (RSDInt.) ranged from 3.7 to 7.3%. The obtained analytical performance characteristics of the method demonstrated its fitness for the purpose, making thus the proposed method suitable to be submitted for the last phase within the standardisation procedure, i.e. the inter-laboratory study.
Ursula Vincent - One of the best experts on this subject based on the ideXlab platform.
-
determination of Semduramicin in poultry feed additive premixture and compound feed by liquid chromatography and uv spectrophotometric detection after post column derivatisation
Journal of Pharmaceutical and Biomedical Analysis, 2012Co-Authors: Ursula Vincent, Federica Serano, Maria Jose Gonzalez De La Huebra, Christoph Von HolstAbstract:A new, simple and fit for purpose method based on liquid chromatography with UV spectrophotometric detection and post-column derivatisation (LC-UV-PCD) for the determination of Semduramicin in poultry compound feed, premixtures and feed additive as well as its discrimination from other coccidiostats in poultry compound feed has been developed and single-laboratory validated. The concentration levels of the target analyte at which the validation experiments have been carried out varied between 12.8 and 51.3 mg kg(-1) in compound feed, covering the authorised levels of Semduramicin according to European Union legislation. Furthermore, the method has been validated for a premixture sample containing Semduramicin at 3 g kg(-1) and the feed additive containing Semduramicin at 51 g kg(-1). The method developed involved a simple extraction of the coccidiostats with acetonitrile from the feed samples followed by a filtration of the supernatants. The resulting supernatants were submitted to chromatographic analysis. When analysing the feed additive and the premixture samples, the extraction solution was appropriately diluted prior to LC-UV-PCD analysis. The analytes were quantified through an external calibration curve prepared with pure Semduramicin standards. The relative standard deviations for repeatability and for intermediate precision varied from 2.4 to 8.8% and from 2.6 to 8.8%, respectively, and the values for the relative recovery rate ranged from 89 to 95%. The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be below 1 mg kg(-1) and 3 mg kg(-1), respectively. Moreover, the results showed a comparable performance profile, when using methyl isobutyl ketone instead of acetonitrile as extraction solvent.Based on the obtained method performance characteristics, the method is considered suitable for the determination of Semduramicin in poultry compound feed at authorised level, in premixtures and in the feed additive, hence allowing the enforcement of the European Union legislation regarding the control and the monitoring in feedingstuffs.
-
interlaboratory comparison of an analytical method for the determination of Semduramicin in poultry feed at the authorized level using high performance liquid chromatography coupled to postcolumn derivatization and spectrophotometric detection
Journal of AOAC International, 2012Co-Authors: Maria Jose Gonzalez De La Huebra, Ursula Vincent, Federica Serano, Christoph Von HolstAbstract:The performance characteristics of a method based on HPLC with postcolumn derivatization and spectrophotometric detection for the quantification of Semduramicin in poultry feedingstuffs have been determined via a collaborative study. Semduramicin is a feed additive that is authorized for fattening chickens within the European Union at a minimum and maximum content of 20 and 25 mg/kg in feedingstuffs, respectively. The target concentration of Semduramicin in the test samples ranged from 11.5 to 45.0 mg/kg. The study has been conducted with two different types of test material, namely, feedingstuff samples that have been previously ground in our laboratory and pelleted feedingstuffs. In the latter case, the laboratories participating in the study had to grind the samples prior to analysis. The obtained RSD for repeatability (RSD(r)) ranged from 2 to 10% for the ground materials, and from 2 and 7% for the pelleted materials. The RSD for reproducibility (RSDR) varied between 11 and 16% for the ground materials, and between 12 and 15% for the pelleted materials. These data indicated that grinding as an additional step in the analytical procedure did not influence the precision profile of the method. In addition, the HorRat values for all test materials were below or equal to 1.5, thus demonstrating that the obtained precision data were acceptable for the purpose of the method. Furthermore, an estimation of trueness based on statistical treatment of the results reported from the laboratories for spiked samples revealed acceptable mean recovery values of 88 +/- 4%. Based on the obtained performance profile, the method can be considered fully validated and transferable to control laboratories to be used within the framework of official control.
-
inter laboratory comparison of an analytical method for the determination of the feed additive Semduramicin in poultry feed at authorised level by liquid chromatography single quadrupole mass spectrometry
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2011Co-Authors: M Gonzalez J De La Huebra, Ursula Vincent, C Von HolstAbstract:A collaborative study was carried out according to internationally recognised guidelines in order to establish the performance characteristics of an LC/MS method for the determination of the feed additive Semduramicin (SEM) in poultry feed at the level (20-25 mg kg(-1)) authorised within the European Union. Fifteen laboratories participated in the validation study, and all reported results. The content of SEM in the tested materials, provided as blind duplicates, ranged from 11.5 mg kg(-1), which corresponds to half the mean authorised level, to 45.0 mg kg(-1), which corresponds to twice the mean authorised level. All the materials were analysed by the participating laboratories using two different quantification approaches: standard addition and external standard calibration. The relative standard deviation of reproducibility (RSD(R)) for both quantification approaches varied from 8% to 18%, corresponding to HORRAT values ranging from 0.8 to 1.5, which were therefore in all cases below the critical value of 2.0. Consequently, the proposed analytical method and both quantification approaches can be considered to be fully validated and transferable to the control laboratories and applied for the determination of SEM in poultry compound feed at authorised level within the frame of official control. Further steps in the administrative procedure aiming to adopt the method as part of an ISO/CEN standard are currently ongoing.
-
determination of Semduramicin in poultry feed at authorized level by liquid chromatography single quadrupole mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2010Co-Authors: Maria Jose Gonzalez De La Huebra, Ursula Vincent, Christoph Von HolstAbstract:Abstract A novel liquid chromatography single quadrupole mass spectrometry (LC–MS) method for the determination of the feed additive Semduramicin, in poultry feed, was developed and single-laboratory validated. This work was selected as a real case scenario to outline the different steps that may be needed whenever the standardisation of an analytical method in the field of methods of analysis for animal feedingstuffs is attempted. In this manuscript the main achievements reached within the development and the single-laboratory validation of an analytical method for the determination of Semduramicin in feedingstuffs are detailed. Semduramicin is extracted from the feedingstuffs with acetonitrile. The obtained extracts are then filtered and diluted appropriately. The separation has been carried out in a reverse phase C18 column using isocratic elution with a mixture of methanol and 20 mM ammonium formate solution as mobile phase. The ammonium adducts have been selected for monitoring the coccidiostats signals in the mass spectrometry detector. The method has been successfully validated for the determination of Semduramicin concentrations ranging between half of the minimum authorized concentration (10 mg kg−1) to twice of the maximum authorized concentration (50 mg kg−1). A good relative standard deviation for repeatability (RSDr) varying from 2.8 to 3.2% has been obtained whereas the relative standard deviation for intermediate precision (RSDInt.) ranged from 3.7 to 7.3%. The obtained analytical performance characteristics of the method demonstrated its fitness for the purpose, making thus the proposed method suitable to be submitted for the last phase within the standardisation procedure, i.e. the inter-laboratory study.
Piotr Jedziniak - One of the best experts on this subject based on the ideXlab platform.
-
distribution of Semduramicin in hen eggs and tissues after administration of cross contaminated feed
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2014Co-Authors: Malgorzata Olejnik, Teresa Szprengierjuszkiewicz, Piotr JedziniakAbstract:Semduramicin is an ionophore coccidiostat used in the poultry industry as a feed additive. Cross-contamination of feeds for non-target animals with Semduramicin is unavoidable. However, it is not known whether undesirable residues of Semduramicin may occur in food after cross-contaminated feed is administered to animals. The aim of the work was to determine the levels of Semduramicin in hen eggs (yolks and albumen) and tissues (liver, muscle, spleen, gizzard, ovarian yolks and ovaries) after administration of feed contaminated with 0.27 mg kg−1 of this coccidiostat. The residues were determined using LC-MS/MS. The distribution pattern confirmed the high lipophilicity of Semduramicin. Residues were found mainly in egg yolks (28.8 µg kg−1), ovarian yolks (19.5 µg kg−1) and liver (2.57 µg kg−1), while hens’ muscle was free from Semduramicin (LOD = 0.1 µg kg−1). Among edible tissues, the maximum level (2 µg kg−1) was exceeded only in the liver.
-
Semduramicin in eggs the incompatibility of feed and food maximum levels
Food Chemistry, 2014Co-Authors: Malgorzata Olejnik, Teresa Szprengierjuszkiewicz, Piotr JedziniakAbstract:Abstract The cross-contamination of non-target feeds with coccidiostats may result in the occurrence of their residues in food of animal origin. To assure food safety, maximum levels (ML) of coccidiostats have been set for both feed and food. However, scientific data are not available on the transfer of some coccidiostats from feed into food. This experiment was therefore designed to verify, whether the administration of compliant Semduramicin-contaminated feed could cause the occurrence of violative residues of coccidiostats in eggs. The laying hens received feed containing 0.27 ± 0.034 mg/kg of Semduramicin (ML = 0.25 mg/kg). Semduramicin residues were detected in whole eggs after two days of administration of Semduramicin-containing diet. A plateau level was achieved (16.1 ± 5.19 μg/kg, mean ± SD) with the concentrations significantly exceeding the maximum level of Semduramicin in eggs (2 μg/kg). The results of this experiment might be a signal for the revision of the ML value.
-
The Determination of Six Ionophore Coccidiostats in Feed by Liquid Chromatography with Postcolumn Derivatisation and Spectrofotometric/Fluorescence Detection
Hindawi Limited, 2013Co-Authors: Małgorzata Olejnik, Piotr Jedziniak, Teresa Szprengier-juszkiewiczAbstract:The control of levels of anticoccidial feed additives in targeted feeds plays an important role in the assurance of efficiency of animal treatment, prevention of drug resistance, and food safety. The robust and labour-efficient method for the simultaneous determination of six ionophore coccidiostats (lasalocid, maduramicin, monensin, narasin, salinomycin, and Semduramicin) in targeted feed has been developed. Properly grinded and homogenized feed sample was spiked with internal standard (monesin methyl ester) and extracted with methanol. The extract was analysed with reversed phase HPLC without any further purification. The separation of the analytes with conventional C18 and core-shell columns was compared. Lasalocid was analysed with fluorescence detection, whereas other ionophores were detected with UV-Vis detector after derivatisation with vanillin in the presence of sulfuric acid. Fortified samples and targeted feeds at authorized levels were used for method validation. Recovery was in the range of 85–110%, depending on the analyte. The within-laboratory reproducibility did not exceed the target value from Horwitz equation. The results of the proficiency tests (z-scores in the range of −1.0 to 1.9) confirmed the reliability of the developed protocol
-
Research Article The Determination of Six Ionophore Coccidiostats in Feed by Liquid Chromatography with Postcolumn Derivatisation and Spectrofotometric/Fluorescence Detection
2013Co-Authors: Mabgorzata Olejnik, Piotr Jedziniak, Teresa Szprengier-juszkiewiczAbstract:Copyright © 2013 Małgorzata Olejnik et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The control of levels of anticoccidial feed additives in targeted feeds plays an important role in the assurance of efficiency of animal treatment, prevention of drug resistance, and food safety. The robust and labour-efficient method for the simultaneous determination of six ionophore coccidiostats (lasalocid, maduramicin, monensin, narasin, salinomycin, and Semduramicin) in targeted feed has been developed. Properly grinded and homogenized feed sample was spiked with internal standard (monesin methyl ester) and extracted with methanol. The extract was analysed with reversed phase HPLC without any further purification. The separation of the analytes with conventional C18 and core-shell columns was compared. Lasalocid was analysed with fluorescence detection, whereas other ionophores were detected with UV-Vis detector after derivatisation with vanillin in the presence of sulfuric acid. Fortified samples and targeted feeds at authorized levels were used for method validation. Recovery was in the range of 85–110%, depending on the analyte. The within-laboratory reproducibility did not exceed the target value from Horwitz equation.The results of the proficiency tests (z-scores in the range of −1.0 to 1.9) confirmed the reliability of the developed protocol. 1
Armi Wanderley Da Nobrega - One of the best experts on this subject based on the ideXlab platform.
-
validation of a liquid chromatography electrospray ionization tandem mass spectrometric method to determine six polyether ionophores in raw uht pasteurized and powdered milk
Food Chemistry, 2016Co-Authors: Mararlene Ulberg Pereira, Bernardete Ferraz Spisso, Rosana Gomes Ferreira, Mychelle Alves Monteiro, Silvana Do Couto Jacob, Betânia De Souza Carlos, Armi Wanderley Da NobregaAbstract:Abstract This study aimed to validate a method developed for the determination of six antibiotics from the polyether ionophore class (lasalocid, maduramicin, monensin, narasin, salinomycin and Semduramicin) at residue levels in raw, UHT, pasteurized and powdered milk using QuEChERS extraction and high performance liquid chromatography coupled to tandem mass spectrometry (HPLC–MS/MS). The validation was conducted under an in-house laboratory protocol that is primarily based on 2002/657/EC Decision, but takes in account the variability of matrix sources. Overall recoveries between 93% and 113% with relative standard deviations up to 16% were obtained under intermediate precision conditions. CCα calculated values did not exceed 20% the Maximum Residue Limit for monensin and 25% the Maximum Levels for all other substances. The method showed to be simple, fast and suitable for verifying the compliance of raw and processed milk samples regarding the limits recommended by Codex Alimentarius and those adopted in European Community for polyether ionophores.
-
simultaneous determination of polyether ionophores macrolides and lincosamides in hen eggs by liquid chromatography electrospray ionization tandem mass spectrometry using a simple solvent extraction
Analytica Chimica Acta, 2010Co-Authors: Bernardete Ferraz Spisso, Rosana Gomes Ferreira, Mararlene Ulberg Pereira, Mychelle Alves Monteiro, Tatiana Avila Cruz, Rafaela Pinto Da Costa, Adelia Mara Belem Lima, Armi Wanderley Da NobregaAbstract:Abstract A liquid chromatography–electrospray ionization tandem mass spectrometric (LC–ESI-MS/MS) method was developed and validated for the determination of residues of 6 polyether ionophores (lasalocid, maduramicin, monensin, narasin, salinomycin, Semduramicin), 3 macrolides (erythromycin, tylosin, clarithromycin) and 1 lincosamide (lincomycin) in eggs. Nigericin was used as qualitative internal standard. Samples were deproteinizated/extracted with acetonitrile without pH adjustments. Aliquots of the extracts were evaporated and reconstituted for injection in the instrument operated in positive multiple reaction monitoring (MRM) mode. The stability of the antibiotics and the intensity of the formed ions were considered in order to select a suitable solvent for the reconstitution of the obtained dry extracts. No clean-up steps were required and matrix effects were controlled by sample dilution, selection of appropriate chromatographic conditions and reduced injection volume. Good within-laboratory reproducibility was obtained, with relative standard deviations (RSD R ) from 4.0 (Semduramicin at 5 μg kg −1 ) to 18.6 (erythromycin at 25 μg kg −1 ) for the ionophores and macrolides. Lincomycin showed the least precise results, with a maximum RSD R of 20.2% at 75 μg kg −1 ). Satisfactory decision limits (CCα) and detection capabilities (CCβ) were also attained. Method limits of detection (LODs) from 0.04 (salinomycin) to 1.6 μg kg −1 (lincomycin) were achieved. Method limits of quantification (LOQs) were from 0.14 to 5.3 μg kg −1 for the same drugs, respectively. All the LOQs, except that obtained for maduramicin were remarkably below the lowest validation level. The proposed method is suitable for routine application in commercial egg samples.
