The performance characteristics of a method for the determination of the marker substance glycero... more The performance characteristics of a method for the determination of the marker substance glycerol triheptanoate (GTH) in processed animal by-products (ABPs) based on gas chromatography (GC) coupled to mass spectrometry (MS) were determined via a collaborative study. Within the European Union GTH needs to be added to the portion of processed ABPs that must not enter the feed and food chain (Categories 1 and 2) at a minimum concentration of 250 mg kg-1 related to the fat fraction of the test samples analysed. The test materials included in the validation study consisted of three meat and bone meal (MBM) and three fat samples that contained GTH at different concentrations ranging from 61 to 455 mg kg-1. The relative standard deviation of repeatability (RSD r) varied from 3.4 to 7.8% and the relative standard deviation of reproducibility (RSD R) varied from 9.0 to 16.5%, corresponding to HORRAT values that were in all cases equal or below the critical value of 2.0. The estimated trueness expressed in terms of average concentration compared to the target concentrations of GTH in all test materials varied from 95 to 107 % confirming acceptable values for the trueness of the method. Based on the acceptable values for the precision and trueness the method is fit for the intended purpose and can be used for official control purposes to determine GTH in processed animal by-products from Category 1 and Category 2.
A high performance liquid chromatographic method with fluorimetric detection for the determinatio... more A high performance liquid chromatographic method with fluorimetric detection for the determination of aflatoxin M 1 (AFM 1) in milk has been optimized and validated according to Commission Decision 2002/657/EC by using the conventional validation approach. The procedure for determining selectivity, recovery, precision, decision limit (CC α), detection capability (CC β) and ruggedness of the method has been reported. The results of the validation process demonstrate the agreement of the method with the provisions of Commission Regulation 401/2006/EC. The mean recovery calculated at three levels of fortification (0.5, 1.0, and 1.5-fold the MRL) was 91% and the maximum relative standard deviation value for the within-laboratory reproducibility was 15%. Limit of detection (LOD) and limit of quantitation (LOQ) values were 0.006 g kg −1 and 0.015 g kg −1 while the CC α and CC β values were 0.058 g kg −1 and 0.065 g kg −1 , respectively. The relative expanded measurement uncertainty of the method was 7%. The method was not affected by slight variations of some critical factors (ruggedness minor changes) as pre-treatment and clean-up of milk samples, thermal treatment and different storage conditions, as well as by major changes valued in terms of milk produced by different species (buffalo, goat and sheep). The method allowed accurate confirmation analyses of milk samples, resulted positive by the screening method. In fact, the Z-score values attained in a proficiency test round were well below the reference value of 1, proving the excellent laboratory performances.
A method for the determination of β-agonists was developed by combining the separation of analyte... more A method for the determination of β-agonists was developed by combining the separation of analytes through high-performance liquid chromatography, with a reversed-phase column, coupled to the pulsed amperometric detection at a glassy carbon electrode. Preliminary experiments, using cyclic voltammetry, allowed for an understanding of the electrochemical behavior of clenbuterol, fenoterol, and terbutaline. By analyzing the electrochemical response, the conditions for detecting the analytes and for cleaning the working electrode were identified. The proposed potential-time profile was designed to prevent contamination of the carbon electrode following consecutive analyses, so ensuring a reproducible and sensitive quantitative determination. The waveform electrochemical parameters, including detection and delay times, have been optimized in terms of sensitivity, detection limits, and long-term response stability. The chromatographic separation was carried out using a C8 column in isocra...
In the post human genome era, several "omics" fields are emerging. Proteomics has experienced a r... more In the post human genome era, several "omics" fields are emerging. Proteomics has experienced a rapid growth in the recent past and has great potential for the future. Proteomic technologies are used with increasing frequency also in nephrology. The aim of this review is to examine the recent application of emerging proteomic technologies to the study of renal physiology and pathophysiology. We highlight the use in renal research of a number of available techniques including 2-dimensional gel electrophoresis, liquid chromatography/mass spectrometry, surface-enhanced laser desorption/ionization, and capillary electrophoresis/mass spectrometry. We examine the role, efficacy and diagnostic potential of the different proteomic approaches, focusing on current difficulties and potential solutions. The integrating role of bioinformatics and the need for standardized procedures for sample preservation and analysis and reporting of results are also discussed. Although the field is still in an embryonic stage, the knowledge gained up to now is important not only for a better understanding of renal physiology and pathophysiology, but also for the identification of disease markers and the development and follow-up of new therapies. This review gives an overview of proteomics, providing background information, outlining the scopes, highlighting the applications in nephrology, and reporting advantages and limitations. (G Ital Nefrol 2008; 25: 169-82)
The performance characteristics of a method for the determination of the marker substance glycero... more The performance characteristics of a method for the determination of the marker substance glycerol triheptanoate (GTH) in processed animal by-products (ABPs) based on gas chromatography (GC) coupled to mass spectrometry (MS) were determined via a collaborative study. Within the European Union GTH needs to be added to the portion of processed ABPs that must not enter the feed and food chain (Categories 1 and 2) at a minimum concentration of 250 mg kg-1 related to the fat fraction of the test samples analysed. The test materials included in the validation study consisted of three meat and bone meal (MBM) and three fat samples that contained GTH at different concentrations ranging from 61 to 455 mg kg-1. The relative standard deviation of repeatability (RSD r) varied from 3.4 to 7.8% and the relative standard deviation of reproducibility (RSD R) varied from 9.0 to 16.5%, corresponding to HORRAT values that were in all cases equal or below the critical value of 2.0. The estimated trueness expressed in terms of average concentration compared to the target concentrations of GTH in all test materials varied from 95 to 107 % confirming acceptable values for the trueness of the method. Based on the acceptable values for the precision and trueness the method is fit for the intended purpose and can be used for official control purposes to determine GTH in processed animal by-products from Category 1 and Category 2.
A high performance liquid chromatographic method with fluorimetric detection for the determinatio... more A high performance liquid chromatographic method with fluorimetric detection for the determination of aflatoxin M 1 (AFM 1) in milk has been optimized and validated according to Commission Decision 2002/657/EC by using the conventional validation approach. The procedure for determining selectivity, recovery, precision, decision limit (CC α), detection capability (CC β) and ruggedness of the method has been reported. The results of the validation process demonstrate the agreement of the method with the provisions of Commission Regulation 401/2006/EC. The mean recovery calculated at three levels of fortification (0.5, 1.0, and 1.5-fold the MRL) was 91% and the maximum relative standard deviation value for the within-laboratory reproducibility was 15%. Limit of detection (LOD) and limit of quantitation (LOQ) values were 0.006 g kg −1 and 0.015 g kg −1 while the CC α and CC β values were 0.058 g kg −1 and 0.065 g kg −1 , respectively. The relative expanded measurement uncertainty of the method was 7%. The method was not affected by slight variations of some critical factors (ruggedness minor changes) as pre-treatment and clean-up of milk samples, thermal treatment and different storage conditions, as well as by major changes valued in terms of milk produced by different species (buffalo, goat and sheep). The method allowed accurate confirmation analyses of milk samples, resulted positive by the screening method. In fact, the Z-score values attained in a proficiency test round were well below the reference value of 1, proving the excellent laboratory performances.
A method for the determination of β-agonists was developed by combining the separation of analyte... more A method for the determination of β-agonists was developed by combining the separation of analytes through high-performance liquid chromatography, with a reversed-phase column, coupled to the pulsed amperometric detection at a glassy carbon electrode. Preliminary experiments, using cyclic voltammetry, allowed for an understanding of the electrochemical behavior of clenbuterol, fenoterol, and terbutaline. By analyzing the electrochemical response, the conditions for detecting the analytes and for cleaning the working electrode were identified. The proposed potential-time profile was designed to prevent contamination of the carbon electrode following consecutive analyses, so ensuring a reproducible and sensitive quantitative determination. The waveform electrochemical parameters, including detection and delay times, have been optimized in terms of sensitivity, detection limits, and long-term response stability. The chromatographic separation was carried out using a C8 column in isocra...
In the post human genome era, several "omics" fields are emerging. Proteomics has experienced a r... more In the post human genome era, several "omics" fields are emerging. Proteomics has experienced a rapid growth in the recent past and has great potential for the future. Proteomic technologies are used with increasing frequency also in nephrology. The aim of this review is to examine the recent application of emerging proteomic technologies to the study of renal physiology and pathophysiology. We highlight the use in renal research of a number of available techniques including 2-dimensional gel electrophoresis, liquid chromatography/mass spectrometry, surface-enhanced laser desorption/ionization, and capillary electrophoresis/mass spectrometry. We examine the role, efficacy and diagnostic potential of the different proteomic approaches, focusing on current difficulties and potential solutions. The integrating role of bioinformatics and the need for standardized procedures for sample preservation and analysis and reporting of results are also discussed. Although the field is still in an embryonic stage, the knowledge gained up to now is important not only for a better understanding of renal physiology and pathophysiology, but also for the identification of disease markers and the development and follow-up of new therapies. This review gives an overview of proteomics, providing background information, outlining the scopes, highlighting the applications in nephrology, and reporting advantages and limitations. (G Ital Nefrol 2008; 25: 169-82)
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