F. Tagliaro - Academia.edu (original) (raw)
Papers by F. Tagliaro
BACKGROUND Carbohydrate deficient transferrin (CDT) is widely accepted as the most specific bioma... more BACKGROUND Carbohydrate deficient transferrin (CDT) is widely accepted as the most specific biomarker of chronic alcohol abuse. CDT is the collective name of minor glycoforms of Tf including, traditionally, asialo- and disialo-Tf. Asialo-Tf is characterized by low concentrations hampering its detectability. It is expected that IFCC1 will soon recommend the exclusion of asialo-Tf from the computation of CDT to help standardization. However, in our opinion, asialo-Tf could provide precious additional information to confirm, e.g. in a forensic context, an elevated CDT result, merely based on disialo-Tf. On this basis, in view of a re-evaluation of the potential of asialo-Tf as an additional biomarker of alcohol abuse, the purpose of our investigation was to compare the two most popular separative techniques, i.e. CE and HPLC, in their ability to detect asialo-Tf in real serum samples. METHODS Samples: 25 serum samples from subjects undergoing screening for alcohol abuse were analyzed in parallel with CE and HPLC. Analysis: CE and HPLC methods according to ref. 2. Statistics: Data were analyzed by using non-parametric and parametric statistics. RESULTS Correlation between asialo- and disialo-Tf. CE: y = 0.311 x \u2013 0.330, r2 = 0.524 (n=25); HPLC: Scarce number of asialo-Tf detected (n=5) Correlation between CE and HPLC to determine disialo-Tf: y = 1.177 x \u2013 0.158, r2 = 0.970 (n=25) Detection ability for asialo-Tf. CE: 25 out 32 (range detected 0.10 \u2013 3.78); HPLC: 5 out 32 (range detected 0.51 \u2013 1.61) Separation efficiency [N = 5.54 \ub7 (tr / w1/2)2].CE: 51,000 pl; HPLC: 4,200 pl CONCLUSIONS Notwithstanding a comparable performance of CE and HPLC in the determination of disialo-Tf, the ability of CE to detect asialo-Tf proved clearly superior. In fact, CE offers a neatly better separation efficiency of Tf glycoforms, providing sharper and more detectable peaks. In addition, the asialo-Tf peak is located in a very flat region of the electropherogram, far from other potentially interfering peaks. The present results strongly support the use of CE in further studies exploring the potential of asialo-Tf as an additional, important biomarker of alcohol abuse. REFERENCES 1 Helander A et al. Clin Chim Acta 2016; 459:19-24. 2 Bortolotti F et al. Clin Chem 2005; 51:2368-71
ELECTROPHORESIS, 2002
An interlaboratory pilot study was performed to determine the reproducibility of mobility paramet... more An interlaboratory pilot study was performed to determine the reproducibility of mobility parameters in capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC). The study was performed by an intended small number of laboratories (three) that used different brands of instruments (two). The effective mobility was corrected using standards by a method that was recently introduced to obtain a more reproducible migration parameter. A test set of 20 acidic test compounds and 5 reference compounds were analyzed during five days in each laboratory using CZE and MEKC. Buffers used consisted of 90 mM borate set at pH 8.4 (CZE) and 20 mM phosphate, 50 mM sodium dodecyl sulfate set at pH 7.5 (MEKC). Analyses were carried out using fused-silica capillaries at an electric field strength of either 52.6 kV/m or 37.5 kV/m. The interlaboratory reproducibility (mean RSD) of the effective mobility was 3.0% for CZE and 6.7% for MEKC. After applying the correction method, these values became 3.0% for CZE and 3.3% for MEKC, which is adequate for systematic toxicological analysis (STA) applications. A significant improvement of reproducibility for the calculated corrected effective mobility mu(eff)c was observed when variations are high. Therefore, it is recommended to use the correction method in interlaboratory situations, especially when instruments and capillaries from different manufacturers are used.
Edizioni Idelson Gnocchi 1908 srl, 2019
Forensic science review, 2011
Alcohol abuse represents a highly relevant medical, social, and economic problem all over the wor... more Alcohol abuse represents a highly relevant medical, social, and economic problem all over the world. The diagnosis of conditions of alcohol use or abuse is complex, requiring different and integrated methodologies; among them the use of biomarkers is a very helpful and objective tool. This review article discusses the currently available biomarkers of alcohol abuse, showing their positive and negative characteristics in terms of detection window, diagnostic sensitivity, diagnostic specificity, and analytical feasibility. Particular attention is dedicated to the most used biomarkers, represented by liver enzymes (AST, ALT, and GGT), MCV, CDT, EtG and EtS, FAEE, and PEth. A critical analysis of the different biomarkers showed wide variability in terms of detection window, sensitivity, and specificity. On this basis, the choice of any indicator should depend on the aim and context for which the diagnosis of alcohol abuse is required (e.g., clinical, fitness for driver's license, fi...
TrAC Trends in Analytical Chemistry, 1996
Medicine, Science and the Law, 2021
The magnitude of the diagnostic benefit conferred by performing histopathological examinations af... more The magnitude of the diagnostic benefit conferred by performing histopathological examinations after medico-legal/forensic autopsies remains debatable. We have tried to address this issue by reviewing a series of histopathology referrals concerning medico-legal autopsies in real-world routine practice. We present an audit of the consultations provided to forensics by clinical pathologists at our institute between 2015 and 2018. Over this period, 493 post-mortem examinations were performed by forensic pathologists. Of these cases, 52 (11%) were referred for histopathology. Gross assessment was requested in 22/52 (42%) cases. Histopathology examination was performed on single organs in 15/52 (29%) cases, primarily on the lung and heart, whereas parenchymatous multi-organ analysis was carried out in 14/52 (27%) cases. Bone-marrow sampling was studied in 4/52 (8%) cases. Immunohistochemistry was needed in 16/52 (31%) cases, special stains in 9/52 (21%) cases and molecular analysis in 4/...
Research Article Analysis of drugs of forensic interest with capillary zone electrophoresis/time-... more Research Article Analysis of drugs of forensic interest with capillary zone electrophoresis/time-of-flight mass spectrometry based on the use of non-volatile buffers The present work is aimed at investigating the influence of the background electrolyte composition and concentration on the separation efficiency and resolution and mass spectrometric detection of illicit drugs in a capillary zone electrophoresis-electrospray ionization-time of flight mass spectrometry (CZE-ESI-TOF MS) system. The effect of phosphate, borate and Tris buffers on the separation and mass spectrometry response of a mixture of 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, methadone, cocaine, morphine, codeine and 6-monoacetylmorphine was studied, in com-parison with a reference ammonium formate separation buffer. Inorganic non-volatile borate and Tris buffers proved hardly suitable for capillary electrophoresis-mass spec-trometry (CE-MS) analysis, but quite unexpectedly ammonium phosphate...
Analytical and Bioanalytical Chemistry, 2016
Annali dell'Istituto superiore di sanità, 2000
Deaths due to road accidents during weekends have become a worrying phenomenon in Italy. With the... more Deaths due to road accidents during weekends have become a worrying phenomenon in Italy. With the aim of highlighting the role of psychotropic substances (alcohol, drugs of abuse) in causing road accidents, a survey based on clinical and chemico-toxicological analyses has been carried out on car drivers in the Veneto region during night weekends since 1994. Rapid clinical screening was carried out on 7952 drivers. 1399 of these, suspected to be under the influence of psychotropic substances, were subjected to complete clinical and toxicological ascertainment involving the following procedures: a) anamnesis, aiming at evidence of possible current or past use of psychotropic substances; b) objective clinical examination, aiming at finding evidence of recent (signs of acute or chronic intoxication) or past use (signs of withdrawal or associated organic pathologies) of psychotropic substances; c) double sampling of blood and urine and chemico-toxicological analysis using immunochemical,...
Therapeutic Drug Monitoring, 2000
In capillary electrophoresis, electrophoretic or electrokinetic separations are carried out in ti... more In capillary electrophoresis, electrophoretic or electrokinetic separations are carried out in tiny capillaries at high voltages (10-30 kV), thus achieving high efficiency (N > 105), resolution power, and mass sensitivity (down to 10(-18)-10(-20) moles). The main characteristics of capillary electrophoresis are versatility of application (from inorganic ions to large DNA fragments), use of different separation modes with different selectivity, low demands on sample volume, negligible running costs, possibility of interfacing with different detection systems including mass spectrometry, and the ruggedness and simplicity of the instrumentation. Capillary electrophoresis applications in the forensic sciences are now rapidly growing, particularly in forensic toxicology. The present paper briefly describes the basic principles of capillary electrophoresis and presents a selected review of its main applications to the analysis of illicit/controlled drugs in biologic samples. An original analytical approach to the determination of carbohydrate deficient transferrin, a new marker of chronic alcohol abuse, based on capillary electrophoresis is also described. It is concluded that the peculiar separation mechanisms and the high complementarity of capillary electrophoresis to chromatography make it a new powerful tool of investigation in the hands of forensic toxicologists.
Analytical and Bioanalytical Chemistry, 2010
Journal of Forensic Sciences
The scope of this book is to give an overview of the basic technical aspects of capillary electro... more The scope of this book is to give an overview of the basic technical aspects of capillary electrophoresis (CE) and to provide more detailed information on its applications to the major analytical fields in clinical biochemistry and forensic science.
Journal of Chromatography B Biomedical Sciences and Applications
Use of synthetic cannabinoids to cheat the toxicological screening
Dextromethorphan is an antitussive drug that is used in many over-the counter cough and cold medi... more Dextromethorphan is an antitussive drug that is used in many over-the counter cough and cold medications all over the world. Levomethorphan, the l-enantiomer of methorphan, is a potent narcotic drug included in the Controlled Substances List (Schedule I) in many countries. In the recent years, an increasing number of heroin seizures containing methorphan has been reported by national and international Warning Systems [1-2]. On this basis there is a need for establishing a chiral method for the separation of methorphan enantiomers or the analysis not only of clandestine preparations containing methorphan but also of biological fluids from methorphan-related deaths and intoxications. The present work was aimed at developing a cyclodextrin-mediated capillary zone electrophoresis (CD-CZE) method suitable for the separation of d- and l- methorphan in both drug seizures and post-mortem blood. The analytical conditions were as follows: 150 mM phosphate buffer at pH 4.4 with 5 mM hydroxypro...
Minerva stomatologica, 1990
An identification method based on the isoelectrofocusing (IEF) assay of the EsD phenotypes in den... more An identification method based on the isoelectrofocusing (IEF) assay of the EsD phenotypes in dental cavity pulp is reported. The IEF has been carried out on polyacrylamide gel (T = 5% and C = 3%), using ampholines ranging pH 4.5-5.4. A pre-focusing of 20 min at 2,000 V, 100 mA and 8 W was used; focusing conditions were: 2,000 V, unlimited current and W, for 75 min at 4 degrees C. Electropherograms were read under UV at 366 nm after reaction with 4-methylumbelliferyl acetate giving a fluorescent product. The content of a single dental cavity has been found to be the smallest amount of sample needed for the assay in alive subjects, excluding dental pathology which could interfered with the results. In bodies, excluding interferences from abnormal preservation conditions, a clear decrease in the reliability of the assay has been observed after the 6th day since the death. In any case, on the basis of the authors' experience, the dental pulp, as compared to blood, seems a preferabl...
Journal of forensic sciences, 1990
In the recent years, capillary electrophoresis (CE) has established itself as a versatile analyti... more In the recent years, capillary electrophoresis (CE) has established itself as a versatile analytical tool in many areas of Forensic Science, including illicit drug analysis, DNA fingerprinting, ink analysis, explosive and ion determination etc. CE uses the differential mobility of ions to perform their separation in fused silica capillaries (internal diameter 20-100 micron, length 20-100 cm) and different detection methods including UV absorption, fluorescence, electric conductivity, mass spectrometry etc. High efficiency, high mass sensitivity, ruggedness, easy and low cost operation and high versatility are the typical features of CE methods, which may be of the highest interest for the forensic analysts. Quite recently, a simple CE method has been published for the rapid determination of nitrite and nitrate, which are major inorganic components of gunshot residues (1). The aim of the present work was to study the application of this method to the analysis of nitrite and nitrate in residues of firearm discharge. The used method proved simpler, cheaper and faster than the traditional approaches to gunshot residue (GSR) analysis based on flameless atomic absorption spectrometry (AAS), atomic emission spectrometry (AES), inductively coupled plasma-mass spectrometry (ICP-MS), or scanning electron microscopy (SEM). The analyses were carried out in a bare fused-silica capillary (75 mm inner diameter) with a 100 mM borate buffer (pH 9.24). The detection was by direct UV absorption at 214 nm wavelength. Separation took place under the voltage of - 15 kV. Bromide was used as the internal standard. Sensitivity was about 1 mM for both nitrite and nitrate. Reproducibility (intraday and day-to-day) was good with relative standard deviations (RSDs) < 1.0% for relative migration times and < 4.5% for peak areas in both standard solutions and real matrices. The method has been applied successfully to a number of samples obtained in firing tests. The distribution of nitrite and nitrate on targets used in tests was studied. Samples from hands of shooters and of non shooters were analyzed and their results were used to establish a suitable interpretative framework. Shooting tests were performed with different weapons and different cartridges. Hair and skin samples from a victim shot in the head were also successfully analyzed for the presence of nitrite and nitrate. This preliminary study indicates that CE offers a sound potential for forensic GSR investigation as a screening technique prior to more expensive and time consuming analytical techniques. The importance of CE in a procedure able to detect GSR produced by leadfree ammunition, where the evidential value of analytical results obtained with SEM can be poor (2), is finally shown.
BACKGROUND Carbohydrate deficient transferrin (CDT) is widely accepted as the most specific bioma... more BACKGROUND Carbohydrate deficient transferrin (CDT) is widely accepted as the most specific biomarker of chronic alcohol abuse. CDT is the collective name of minor glycoforms of Tf including, traditionally, asialo- and disialo-Tf. Asialo-Tf is characterized by low concentrations hampering its detectability. It is expected that IFCC1 will soon recommend the exclusion of asialo-Tf from the computation of CDT to help standardization. However, in our opinion, asialo-Tf could provide precious additional information to confirm, e.g. in a forensic context, an elevated CDT result, merely based on disialo-Tf. On this basis, in view of a re-evaluation of the potential of asialo-Tf as an additional biomarker of alcohol abuse, the purpose of our investigation was to compare the two most popular separative techniques, i.e. CE and HPLC, in their ability to detect asialo-Tf in real serum samples. METHODS Samples: 25 serum samples from subjects undergoing screening for alcohol abuse were analyzed in parallel with CE and HPLC. Analysis: CE and HPLC methods according to ref. 2. Statistics: Data were analyzed by using non-parametric and parametric statistics. RESULTS Correlation between asialo- and disialo-Tf. CE: y = 0.311 x \u2013 0.330, r2 = 0.524 (n=25); HPLC: Scarce number of asialo-Tf detected (n=5) Correlation between CE and HPLC to determine disialo-Tf: y = 1.177 x \u2013 0.158, r2 = 0.970 (n=25) Detection ability for asialo-Tf. CE: 25 out 32 (range detected 0.10 \u2013 3.78); HPLC: 5 out 32 (range detected 0.51 \u2013 1.61) Separation efficiency [N = 5.54 \ub7 (tr / w1/2)2].CE: 51,000 pl; HPLC: 4,200 pl CONCLUSIONS Notwithstanding a comparable performance of CE and HPLC in the determination of disialo-Tf, the ability of CE to detect asialo-Tf proved clearly superior. In fact, CE offers a neatly better separation efficiency of Tf glycoforms, providing sharper and more detectable peaks. In addition, the asialo-Tf peak is located in a very flat region of the electropherogram, far from other potentially interfering peaks. The present results strongly support the use of CE in further studies exploring the potential of asialo-Tf as an additional, important biomarker of alcohol abuse. REFERENCES 1 Helander A et al. Clin Chim Acta 2016; 459:19-24. 2 Bortolotti F et al. Clin Chem 2005; 51:2368-71
ELECTROPHORESIS, 2002
An interlaboratory pilot study was performed to determine the reproducibility of mobility paramet... more An interlaboratory pilot study was performed to determine the reproducibility of mobility parameters in capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC). The study was performed by an intended small number of laboratories (three) that used different brands of instruments (two). The effective mobility was corrected using standards by a method that was recently introduced to obtain a more reproducible migration parameter. A test set of 20 acidic test compounds and 5 reference compounds were analyzed during five days in each laboratory using CZE and MEKC. Buffers used consisted of 90 mM borate set at pH 8.4 (CZE) and 20 mM phosphate, 50 mM sodium dodecyl sulfate set at pH 7.5 (MEKC). Analyses were carried out using fused-silica capillaries at an electric field strength of either 52.6 kV/m or 37.5 kV/m. The interlaboratory reproducibility (mean RSD) of the effective mobility was 3.0% for CZE and 6.7% for MEKC. After applying the correction method, these values became 3.0% for CZE and 3.3% for MEKC, which is adequate for systematic toxicological analysis (STA) applications. A significant improvement of reproducibility for the calculated corrected effective mobility mu(eff)c was observed when variations are high. Therefore, it is recommended to use the correction method in interlaboratory situations, especially when instruments and capillaries from different manufacturers are used.
Edizioni Idelson Gnocchi 1908 srl, 2019
Forensic science review, 2011
Alcohol abuse represents a highly relevant medical, social, and economic problem all over the wor... more Alcohol abuse represents a highly relevant medical, social, and economic problem all over the world. The diagnosis of conditions of alcohol use or abuse is complex, requiring different and integrated methodologies; among them the use of biomarkers is a very helpful and objective tool. This review article discusses the currently available biomarkers of alcohol abuse, showing their positive and negative characteristics in terms of detection window, diagnostic sensitivity, diagnostic specificity, and analytical feasibility. Particular attention is dedicated to the most used biomarkers, represented by liver enzymes (AST, ALT, and GGT), MCV, CDT, EtG and EtS, FAEE, and PEth. A critical analysis of the different biomarkers showed wide variability in terms of detection window, sensitivity, and specificity. On this basis, the choice of any indicator should depend on the aim and context for which the diagnosis of alcohol abuse is required (e.g., clinical, fitness for driver's license, fi...
TrAC Trends in Analytical Chemistry, 1996
Medicine, Science and the Law, 2021
The magnitude of the diagnostic benefit conferred by performing histopathological examinations af... more The magnitude of the diagnostic benefit conferred by performing histopathological examinations after medico-legal/forensic autopsies remains debatable. We have tried to address this issue by reviewing a series of histopathology referrals concerning medico-legal autopsies in real-world routine practice. We present an audit of the consultations provided to forensics by clinical pathologists at our institute between 2015 and 2018. Over this period, 493 post-mortem examinations were performed by forensic pathologists. Of these cases, 52 (11%) were referred for histopathology. Gross assessment was requested in 22/52 (42%) cases. Histopathology examination was performed on single organs in 15/52 (29%) cases, primarily on the lung and heart, whereas parenchymatous multi-organ analysis was carried out in 14/52 (27%) cases. Bone-marrow sampling was studied in 4/52 (8%) cases. Immunohistochemistry was needed in 16/52 (31%) cases, special stains in 9/52 (21%) cases and molecular analysis in 4/...
Research Article Analysis of drugs of forensic interest with capillary zone electrophoresis/time-... more Research Article Analysis of drugs of forensic interest with capillary zone electrophoresis/time-of-flight mass spectrometry based on the use of non-volatile buffers The present work is aimed at investigating the influence of the background electrolyte composition and concentration on the separation efficiency and resolution and mass spectrometric detection of illicit drugs in a capillary zone electrophoresis-electrospray ionization-time of flight mass spectrometry (CZE-ESI-TOF MS) system. The effect of phosphate, borate and Tris buffers on the separation and mass spectrometry response of a mixture of 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, methadone, cocaine, morphine, codeine and 6-monoacetylmorphine was studied, in com-parison with a reference ammonium formate separation buffer. Inorganic non-volatile borate and Tris buffers proved hardly suitable for capillary electrophoresis-mass spec-trometry (CE-MS) analysis, but quite unexpectedly ammonium phosphate...
Analytical and Bioanalytical Chemistry, 2016
Annali dell'Istituto superiore di sanità, 2000
Deaths due to road accidents during weekends have become a worrying phenomenon in Italy. With the... more Deaths due to road accidents during weekends have become a worrying phenomenon in Italy. With the aim of highlighting the role of psychotropic substances (alcohol, drugs of abuse) in causing road accidents, a survey based on clinical and chemico-toxicological analyses has been carried out on car drivers in the Veneto region during night weekends since 1994. Rapid clinical screening was carried out on 7952 drivers. 1399 of these, suspected to be under the influence of psychotropic substances, were subjected to complete clinical and toxicological ascertainment involving the following procedures: a) anamnesis, aiming at evidence of possible current or past use of psychotropic substances; b) objective clinical examination, aiming at finding evidence of recent (signs of acute or chronic intoxication) or past use (signs of withdrawal or associated organic pathologies) of psychotropic substances; c) double sampling of blood and urine and chemico-toxicological analysis using immunochemical,...
Therapeutic Drug Monitoring, 2000
In capillary electrophoresis, electrophoretic or electrokinetic separations are carried out in ti... more In capillary electrophoresis, electrophoretic or electrokinetic separations are carried out in tiny capillaries at high voltages (10-30 kV), thus achieving high efficiency (N > 105), resolution power, and mass sensitivity (down to 10(-18)-10(-20) moles). The main characteristics of capillary electrophoresis are versatility of application (from inorganic ions to large DNA fragments), use of different separation modes with different selectivity, low demands on sample volume, negligible running costs, possibility of interfacing with different detection systems including mass spectrometry, and the ruggedness and simplicity of the instrumentation. Capillary electrophoresis applications in the forensic sciences are now rapidly growing, particularly in forensic toxicology. The present paper briefly describes the basic principles of capillary electrophoresis and presents a selected review of its main applications to the analysis of illicit/controlled drugs in biologic samples. An original analytical approach to the determination of carbohydrate deficient transferrin, a new marker of chronic alcohol abuse, based on capillary electrophoresis is also described. It is concluded that the peculiar separation mechanisms and the high complementarity of capillary electrophoresis to chromatography make it a new powerful tool of investigation in the hands of forensic toxicologists.
Analytical and Bioanalytical Chemistry, 2010
Journal of Forensic Sciences
The scope of this book is to give an overview of the basic technical aspects of capillary electro... more The scope of this book is to give an overview of the basic technical aspects of capillary electrophoresis (CE) and to provide more detailed information on its applications to the major analytical fields in clinical biochemistry and forensic science.
Journal of Chromatography B Biomedical Sciences and Applications
Use of synthetic cannabinoids to cheat the toxicological screening
Dextromethorphan is an antitussive drug that is used in many over-the counter cough and cold medi... more Dextromethorphan is an antitussive drug that is used in many over-the counter cough and cold medications all over the world. Levomethorphan, the l-enantiomer of methorphan, is a potent narcotic drug included in the Controlled Substances List (Schedule I) in many countries. In the recent years, an increasing number of heroin seizures containing methorphan has been reported by national and international Warning Systems [1-2]. On this basis there is a need for establishing a chiral method for the separation of methorphan enantiomers or the analysis not only of clandestine preparations containing methorphan but also of biological fluids from methorphan-related deaths and intoxications. The present work was aimed at developing a cyclodextrin-mediated capillary zone electrophoresis (CD-CZE) method suitable for the separation of d- and l- methorphan in both drug seizures and post-mortem blood. The analytical conditions were as follows: 150 mM phosphate buffer at pH 4.4 with 5 mM hydroxypro...
Minerva stomatologica, 1990
An identification method based on the isoelectrofocusing (IEF) assay of the EsD phenotypes in den... more An identification method based on the isoelectrofocusing (IEF) assay of the EsD phenotypes in dental cavity pulp is reported. The IEF has been carried out on polyacrylamide gel (T = 5% and C = 3%), using ampholines ranging pH 4.5-5.4. A pre-focusing of 20 min at 2,000 V, 100 mA and 8 W was used; focusing conditions were: 2,000 V, unlimited current and W, for 75 min at 4 degrees C. Electropherograms were read under UV at 366 nm after reaction with 4-methylumbelliferyl acetate giving a fluorescent product. The content of a single dental cavity has been found to be the smallest amount of sample needed for the assay in alive subjects, excluding dental pathology which could interfered with the results. In bodies, excluding interferences from abnormal preservation conditions, a clear decrease in the reliability of the assay has been observed after the 6th day since the death. In any case, on the basis of the authors' experience, the dental pulp, as compared to blood, seems a preferabl...
Journal of forensic sciences, 1990
In the recent years, capillary electrophoresis (CE) has established itself as a versatile analyti... more In the recent years, capillary electrophoresis (CE) has established itself as a versatile analytical tool in many areas of Forensic Science, including illicit drug analysis, DNA fingerprinting, ink analysis, explosive and ion determination etc. CE uses the differential mobility of ions to perform their separation in fused silica capillaries (internal diameter 20-100 micron, length 20-100 cm) and different detection methods including UV absorption, fluorescence, electric conductivity, mass spectrometry etc. High efficiency, high mass sensitivity, ruggedness, easy and low cost operation and high versatility are the typical features of CE methods, which may be of the highest interest for the forensic analysts. Quite recently, a simple CE method has been published for the rapid determination of nitrite and nitrate, which are major inorganic components of gunshot residues (1). The aim of the present work was to study the application of this method to the analysis of nitrite and nitrate in residues of firearm discharge. The used method proved simpler, cheaper and faster than the traditional approaches to gunshot residue (GSR) analysis based on flameless atomic absorption spectrometry (AAS), atomic emission spectrometry (AES), inductively coupled plasma-mass spectrometry (ICP-MS), or scanning electron microscopy (SEM). The analyses were carried out in a bare fused-silica capillary (75 mm inner diameter) with a 100 mM borate buffer (pH 9.24). The detection was by direct UV absorption at 214 nm wavelength. Separation took place under the voltage of - 15 kV. Bromide was used as the internal standard. Sensitivity was about 1 mM for both nitrite and nitrate. Reproducibility (intraday and day-to-day) was good with relative standard deviations (RSDs) < 1.0% for relative migration times and < 4.5% for peak areas in both standard solutions and real matrices. The method has been applied successfully to a number of samples obtained in firing tests. The distribution of nitrite and nitrate on targets used in tests was studied. Samples from hands of shooters and of non shooters were analyzed and their results were used to establish a suitable interpretative framework. Shooting tests were performed with different weapons and different cartridges. Hair and skin samples from a victim shot in the head were also successfully analyzed for the presence of nitrite and nitrate. This preliminary study indicates that CE offers a sound potential for forensic GSR investigation as a screening technique prior to more expensive and time consuming analytical techniques. The importance of CE in a procedure able to detect GSR produced by leadfree ammunition, where the evidential value of analytical results obtained with SEM can be poor (2), is finally shown.