DOCSLIB.ORG

High Performance Liquid Chromatography Method Development and Chemometric Analysis of Ecstasy and Cocaine

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

institlüld ictterkcnny TeicneoUiochti institute lyit (.«Ulf C*»n«lon of Technology High performance liquid chromatography method development and chemometric analysis of ecstasy and cocaine Kim McFadden Supervisors Dr. B. F. Carney, Letterkenny Institute of Technology Dr. D. O'Driscoll, Forensic Science Laboratory, Dublin Submitted to Higher bducation and Training Awards Council (HETAC) in fulfilment for the requirements for the degree of Doctor of Philosophy HPLC method development & chemomelric analysis of ecstasy & cocaine Declaration I hereby declare that the work herein, submitted for Ph.D. in Analytical Science at Letterkenny Institute of Technology, is the result of my own investigation, except where reference is made to published literature. I also certify that the material submitted in this thesis has not been previously submitted for any other qualification. Kim McFadden 1 HPLC method development & chemometric analysis of ecstasy & cocaine Table of Contents Declaration 1 Abstract 5 List of Abbreviations 7 List of Figures 10 List of Tables 14 List of Presentations and Publications 16 Acknowledgments 18 Chapter 1: Literature review. 19 1.1. Introduction. 20 1.2. Drugs of abuse. 21 1.2.1. Narcotics. 22 1.2.2. Depressants. 24 1.2.3. Stimulants. 24 1.2.4. Hallucinogens. 25 1.2.5. Ecstasy. 26 1.2.6. Cocaine. 31 1.3. Current analytical techniques for forensic drug analysis. 34 1.3.1. Spectrometric methods. 34 1.3.2. Chromatographic methods. 36 1.4. Fundamentals of High Performance Liquid Chromatography. 40 1.4.1. Chromatographic interactions. 40 1.4.2. Mobile phase. 41 1.4.3. The column. 42 1.4.4. Applications of monolithic columns in the area of forensic drug analysis. 45 1.5. Chemometrics and statistical profiling. 50 1.5.1. Experimental design. 50 1.5.2. Drug classification. 52 1.5.3 Application of chemometrics to illicit drug profiling. 57 1.6. Legislation and control efforts in Ireland. 61 1.7. Aims and objectives. 63 2 HPLC method development & chemometric analysis of ecstasy & cocaine Chapter 2: Materials and methods. 66 2.1. General materials and instrumentation. 67 2.1.1. Chemicals and reagents. 67 2.1.2. Liquid chromatography system. 67 2.1.3. Atomic absorption spectrometry. 68 2.1.4. Miscellaneous instruments. 68 2.1.5. Computer software. 68 2.2. Univariate HPLC method development for the analysis of ecstasy. 69 2.2.1. Ecstasy standards and sample preparation. 69 2.2.2. Univariate method development for analysis of ecstasy. 71 2.2.3. Validation of univariate method-developed. 73 2.3. Multivariate HPLC method development for the analysis of cocaine. 74 2.3.1. Cocaine standards and sample preparation. 74 2.3.2. Multivariate method development for analysis of cocaine. 75 2.3.3. Validation of multivariate method developed. 79 2.4. Sugar analysis. 79 2.5. Metal analysis. 79 2.6. Data analysis and chemometric procedures. 81 2.6.1. Ecstasy data and pre-treatments. 81 2.6.2. Ecstasy data pattern recognition. 82 Chapter 3: HPLC method development. 85 3.1. Univariate HPLC method development for the analysis of ecstasy. 86 3.1.1. Chromatographic factors. 86 3.1.2. Selection of optimal HPLC conditions for ecstasy sample analysis. 92 3.1.3. Comparison of particulate and monolithic columns. 98 3.1.4. Validation of univariate method developed. 101 3.1.5. Conclusions. 105 3.2. Multivariate HPLC method development for the analysis of cocaine. 106 3.2.1. Multivariate method development. 106 3.2.2. Response surfaces. 113 3 HPLC method development & chemometric analysis of ecstasy & cocaine 3.2.3. Validation of multivariate method developed. 116 3.2.4. Conclusions. 118 Chapter 4: Physical and chemical analysis of illicit drug samples. 119 4.1. Ecstasy analysis. 120 4.1.1. Physical profile of ecstasy. 120 4.1.2. Chemical analysis of ecstasy. 124 4.1.3. General profiling of ecstasy. 128 4.1.4. Discussion. 132 4.2. Chemical analysis of cocaine. 136 4.2.1. Discussion. 139 4.3. Conclusions. 141 Chapter 5: Chemometrics and statistical profiling of ecstasy tablets. 143 5.1. Introduction. 144 5.2. Ecstasy data pre-treatment methods. 144 5.3. Ecstasy data pattern recognition methods. 149 5.3.1. Principal component analysis. 149 5.3.2. Hierarchal cluster analysis. 153 5.3.3. Pearson’s correlation coefficient. 159 5.4. Supervised pattern recognition methods. 165 5.5. Conclusions. 171 Chapter 6: Conclusions and future work. 173 6.1. Method development. 174 6.2. Analysis of illicit drug samples. 175 6.3. Chemometrics and statistical profiling of ecstasy samples. 176 6.4. Establishing a profiling protocol in a forensic laboratory. 177 6.5. Future studies on the current major drugs in Ireland. 178 References 181 Appendices 209 4 HPLC method development & chemometric analysis of ecstasy & cocaine Abstract Consumption of illegal drugs of abuse remains a major social issue aligned with a global law-enforcement priority. Forensic analysts are faced with the challenge of continually developing sophisticated methods of analysis to combat the increasing variability that occurs in illicit drug samples. Research work for this thesis has focused on the development of High Performance Liquid Chromatography (HPLC) methods for the analysis of major drug constituents associated with ecstasy and cocaine illicit drug samples. Emphasis has been placed on method development with strategies of univariate or multivariate experimental approaches used in the selection and optimisation of procedures. Considerations with regard to the choice of chromatographic factors, solutes under investigation and the provision of quality assurance data throughout the research work have been the main criteria in methods developed. Two HPLC methods were developed to qualitatively and quantitatively assay for the major drug components and analogue derivatives found in ecstasy and cocaine. Methods developed have undergone validation studies including intra- and inter- reproducibility, accuracy, and linearity of calibration, limit of detection (LOD) and limit of quantification (LOQ) and the use of internal standards. Applications of methods to ecstasy and cocaine samples seized in Ireland ensured their suitability for routine analysis of illicit drug samples. As part of this study, chemical profiling of 183 ecstasy tablets seized in Ireland during 2002-2004 were recorded as discrete data sets. Chemical data sets include both the quantification and occurrence in individual tablets of the major amphetamine components (i.e. MDA, MDMA, MDEA, MBDB methamphetamine and amphetamine), adulterant components (i.e. caffeine, phenacetin, acetaminophen and acetylsalicylic acid), excipients components (i.e. sucrose, glucose, lactose, fructose, mannitol, sorbitol and inositol) and inorganic components (i.e. Al, Zn, Fe, Mg, Ca, Cr, Pb, Na and K ). Chemometrics, including unsupervised methods of principal component analysis (PCA), hierarchical cluster analysis (HCA) and Pearson’s correlation coefficient, as well as supervised methods of linear discriminant analysis (LDA) and artificial neural networks (ANN) was applied to the chemical data sets to demonstrate the ability of the statistical approach to linking sample seizures. HCA and ANN were the numerical methods that most efficiently distinguished between 5 HPLC method development & chemometric analysis of ecstasy & cocaine linked and unlinked seizures. Eleven groups were identified from the chemical data sets with group classification dependant on the main amphetamine, adulterant and excipient components present. The benefits from this study can provide strategic intelligence and an understanding of the operational level on the Irish ecstasy market and help evaluate the changing profile or dynamics associated with this illegal market supply. 6 HPLC method development & chemometric analysis of ecstasy & cocaine List of Abbreviations 2C-B 4-bromo-2, 5-dimethoxyphenethylamine A Amphetamine AA Atomic absorption ACN Acetonitrile ADRU Alcohol and drug research unit ANN Artificial neural networks ASA Acetylsalicylic acid ATS Amphetamine - type - stimulants BZP 1 - Benzylpiperazine CE Capillary electrophoresis CV Coefficient of variation DAD Diode array detection DAP Drug awareness programmme DEA Drug enforcement agency DIMS Drugs information monitoring system DOB 4-bromo-2, 5-dimethoxyamphetamine DOM 4-Methyl-2, 5-dimethoxyamphetamine ECD Electron capture detector ELSD Evaporative light scattering detection EMCDDA European monitoring centre for drugs and drug addiction ENFS1 European network of forensic science institutes FID Flame ionization detector GBL Gamma - butyrolactone GC Gas chromatography GC-MS Gas chromatography-mass spectrometry GHB Gamma hyrdoxybutyric acid HCA Hierarchal cluster analysis HPLC High performance liquid chromatography HETP Height equivalent to theoretical plate HRB Health research board ICH International conference on harmonisation IEC Ion-exchange chromatography 7 HPLC method development & chemometric analysis of ecstasy & cocaine INCB International narcotics control board INEF Irish needle exchange forum IR Infra red k’ Retention factor k’ave? Average retention factor KNN K-nearest neighbour LC Liquid chromatography LC-MS Liquid chromatography-mass spectrometry LDA Linear discriminant analysis LLE Liquid-liquid extraction LOD Limit of detection LOQ Limit of quantification LSD Lysergic acid diethylamide MAOC-N Maritime analysis and operations centre - narcotics MDA 3, 4-Methylenedioxyamphetamine MDEA 3, 4-Methylenedioxy-N-ethylamphetamine MDMA 3,4-Methylenedioxymethamphetamine MBDB N-methyl-1 -1 -(1, 3-benzdioxoI-5-yl)-2-butanamine
Recommended publications
  • Chapter 9 Titrimetric Methods 413

    Chapter 9 Titrimetric Methods 413

    Chapter 9 Titrimetric Methods Chapter Overview Section 9A Overview of Titrimetry Section 9B Acid–Base Titrations Section 9C Complexation Titrations Section 9D Redox Titrations Section 9E Precipitation Titrations Section 9F Key Terms Section 9G Chapter Summary Section 9H Problems Section 9I Solutions to Practice Exercises Titrimetry, in which volume serves as the analytical signal, made its first appearance as an analytical method in the early eighteenth century. Titrimetric methods were not well received by the analytical chemists of that era because they could not duplicate the accuracy and precision of a gravimetric analysis. Not surprisingly, few standard texts from the 1700s and 1800s include titrimetric methods of analysis. Precipitation gravimetry developed as an analytical method without a general theory of precipitation. An empirical relationship between a precipitate’s mass and the mass of analyte— what analytical chemists call a gravimetric factor—was determined experimentally by taking a known mass of analyte through the procedure. Today, we recognize this as an early example of an external standardization. Gravimetric factors were not calculated using the stoichiometry of a precipitation reaction because chemical formulas and atomic weights were not yet available! Unlike gravimetry, the development and acceptance of titrimetry required a deeper understanding of stoichiometry, of thermodynamics, and of chemical equilibria. By the 1900s, the accuracy and precision of titrimetric methods were comparable to that of gravimetric methods, establishing titrimetry as an accepted analytical technique. 411 412 Analytical Chemistry 2.0 9A Overview of Titrimetry We are deliberately avoiding the term In titrimetry we add a reagent, called the titrant, to a solution contain- analyte at this point in our introduction ing another reagent, called the titrand, and allow them to react.
  • Sassafras Tea: Using a Traditional Method of Preparation to Reduce the Carcinogenic Compound Safrole Kate Cummings Clemson University, Kecummi@G.Clemson.Edu

    Sassafras Tea: Using a Traditional Method of Preparation to Reduce the Carcinogenic Compound Safrole Kate Cummings Clemson University, [email protected]

    Clemson University TigerPrints All Theses Theses 5-2012 Sassafras Tea: Using a Traditional Method of Preparation to Reduce the Carcinogenic Compound Safrole Kate Cummings Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_theses Part of the Forest Sciences Commons Recommended Citation Cummings, Kate, "Sassafras Tea: Using a Traditional Method of Preparation to Reduce the Carcinogenic Compound Safrole" (2012). All Theses. 1345. https://tigerprints.clemson.edu/all_theses/1345 This Thesis is brought to you for free and open access by the Theses at TigerPrints. It has been accepted for inclusion in All Theses by an authorized administrator of TigerPrints. For more information, please contact [email protected]. SASSAFRAS TEA: USING A TRADITIONAL METHOD OF PREPARATION TO REDUCE THE CARCINOGENIC COMPOUND SAFROLE A Thesis Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Master of Science Forest Resources by Kate Cummings May 2012 Accepted by: Patricia Layton, Ph.D., Committee Chair Karen C. Hall, Ph.D Feng Chen, Ph. D. Christina Wells, Ph. D. ABSTRACT The purpose of this research is to quantify the carcinogenic compound safrole in the traditional preparation method of making sassafras tea from the root of Sassafras albidum. The traditional method investigated was typical of preparation by members of the Eastern Band of Cherokee Indians and other Appalachian peoples. Sassafras is a tree common to the eastern coast of the United States, especially in the mountainous regions. Historically and continuing until today, roots of the tree are used to prepare fragrant teas and syrups.
  • Precursors and Chemicals Frequently Used in the Illicit Manufacture of Narcotic Drugs and Psychotropic Substances 2017

    Precursors and Chemicals Frequently Used in the Illicit Manufacture of Narcotic Drugs and Psychotropic Substances 2017

    INTERNATIONAL NARCOTICS CONTROL BOARD Precursors and chemicals frequently used in the illicit manufacture of narcotic drugs and psychotropic substances 2017 EMBARGO Observe release date: Not to be published or broadcast before Thursday, 1 March 2018, at 1100 hours (CET) UNITED NATIONS CAUTION Reports published by the International Narcotics Control Board in 2017 The Report of the International Narcotics Control Board for 2017 (E/INCB/2017/1) is supplemented by the following reports: Narcotic Drugs: Estimated World Requirements for 2018—Statistics for 2016 (E/INCB/2017/2) Psychotropic Substances: Statistics for 2016—Assessments of Annual Medical and Scientific Requirements for Substances in Schedules II, III and IV of the Convention on Psychotropic Substances of 1971 (E/INCB/2017/3) Precursors and Chemicals Frequently Used in the Illicit Manufacture of Narcotic Drugs and Psychotropic Substances: Report of the International Narcotics Control Board for 2017 on the Implementation of Article 12 of the United Nations Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances of 1988 (E/INCB/2017/4) The updated lists of substances under international control, comprising narcotic drugs, psychotropic substances and substances frequently used in the illicit manufacture of narcotic drugs and psychotropic substances, are contained in the latest editions of the annexes to the statistical forms (“Yellow List”, “Green List” and “Red List”), which are also issued by the Board. Contacting the International Narcotics Control Board The secretariat of the Board may be reached at the following address: Vienna International Centre Room E-1339 P.O. Box 500 1400 Vienna Austria In addition, the following may be used to contact the secretariat: Telephone: (+43-1) 26060 Fax: (+43-1) 26060-5867 or 26060-5868 Email: [email protected] The text of the present report is also available on the website of the Board (www.incb.org).
  • Analytical Chemistry Laboratory Manual 2

    Analytical Chemistry Laboratory Manual 2

    ANALYTICAL CHEMISTRY LABORATORY MANUAL 2 Ankara University Faculty of Pharmacy Department of Analytical Chemistry Analytical Chemistry Practices Contents INTRODUCTION TO QUANTITATIVE ANALYSIS ......................................................................... 2 VOLUMETRIC ANALYSIS .............................................................................................................. 2 Volumetric Analysis Calculations ................................................................................................... 3 Dilution Factor ................................................................................................................................ 4 Standard Solutions ........................................................................................................................... 5 Primary standard .............................................................................................................................. 5 Characteristics of Quantitative Reaction ......................................................................................... 5 Preparation of 1 L 0.1 M HCl Solution ........................................................................................... 6 Preparation of 1 L 0.1 M NaOH Solution ....................................................................................... 6 NEUTRALIZATION TITRATIONS ...................................................................................................... 7 STANDARDIZATION OF 0.1 N NaOH SOLUTION ......................................................................
  • Chapter 8: Gravimetric Methods

    Chapter 8: Gravimetric Methods

    Chapter 8 Gravimetric Methods Chapter Overview 8A Overview of Gravimetric Methods 8B Precipitation Gravimetry 8C Volatilization Gravimetry 8D Particulate Gravimetry 8E Key Terms 8F Chapter Summary 8G Problems 8H Solutions to Practice Exercises Gravimetry includes all analytical methods in which the analytical signal is a measurement of mass or a change in mass. When you step on a scale after exercising you are making, in a sense, a gravimetric determination of your mass. Mass is the most fundamental of all analytical measurements, and gravimetry is unquestionably our oldest quantitative analytical technique. The publication in 1540 of Vannoccio Biringuccio’sPirotechnia is an early example of applying gravimetry—although not yet known by this name—to the analysis of metals and ores.1 Although gravimetry no longer is the most important analytical method, it continues to find use in specialized applications. 1 Smith, C. S.; Gnodi, M. T. translation of Biringuccio, V. Pirotechnia, MIT Press: Cambridge, MA, 1959. 355 356 Analytical Chemistry 2.0 8A Overview of Gravimetric Methods Before we consider specific gravimetric methods, let’s take a moment to develop a broad survey of gravimetry. Later, as you read through the de- scriptions of specific gravimetric methods, this survey will help you focus on their similarities instead of their differences. You will find that it is easier to understand a new analytical method when you can see its relationship to other similar methods. 8A.1 Using Mass as an Analytical Signal Method 2540D in Standard Methods for Suppose you are to determine the total suspended solids in the water re- the Examination of Waters and Wastewaters, leased by a sewage-treatment facility.
  • Biomolecules

    Biomolecules

    biomolecules Communication MBLinhibitors.com, a Website Resource Offering Information and Expertise for the Continued Development of Metallo-β-Lactamase Inhibitors Zishuo Cheng 1, Caitlyn A. Thomas 1, Adam R. Joyner 2, Robert L. Kimble 1, Aidan M. Sturgill 1 , Nhu-Y Tran 1, Maya R. Vulcan 1, Spencer A. Klinsky 1, Diego J. Orea 1, Cody R. Platt 2, Fanpu Cao 2, Bo Li 2, Qilin Yang 2, Cole J. Yurkiewicz 1, Walter Fast 3 and Michael W. Crowder 1,* 1 Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA; [email protected] (Z.C.); [email protected] (C.A.T.); [email protected] (R.L.K.); [email protected] (A.M.S.); [email protected] (N.-Y.T.); [email protected] (M.R.V.); [email protected] (S.A.K.); [email protected] (D.J.O.); [email protected] (C.J.Y.) 2 Department of Computer Science and Software Engineering, Miami University, Oxford, OH 45056, USA; [email protected] (A.R.J.); [email protected] (C.R.P.); [email protected] (F.C.); [email protected] (B.L.); [email protected] (Q.Y.) 3 Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy and the LaMontagne Center for Infectious Disease, University of Texas, Austin, TX 78712, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-513-529-2813 Received: 17 February 2020; Accepted: 12 March 2020; Published: 16 March 2020 Abstract: In an effort to facilitate the discovery of new, improved inhibitors of the metallo-β-lactamases (MBLs), a new, interactive website called MBLinhibitors.com was developed.
  • Methyleugenol (4-Allyl-1,2-Dimethoxybenzene)

    Methyleugenol (4-Allyl-1,2-Dimethoxybenzene)

    EUROPEAN COMMISSION HEALTH & CONSUMER PROTECTION DIRECTORATE-GENERAL Directorate C - Scientific Opinions C2 - Management of scientific committees II; scientific co-operation and networks Scientific Committee on Food SCF/CS/FLAV/FLAVOUR/4 ADD1 FINAL 26 September 2001 Opinion of the Scientific Committee on Food on Methyleugenol (4-Allyl-1,2-dimethoxybenzene) (adopted on 26 September 2001) Rue de la Loi 200, B-1049 Bruxelles/Wetstraat 200, B-1049 Brussel - Belgium - Office: F101 - 6/172 Telephone: direct line (+32-2) 295.4861, switchboard 299.11.11. Fax: (+32-2) 299.4891 Telex: COMEU B 21877. Telegraphic address: COMEUR Brussels http://europa.eu.int/comm/food/fs/sc/scf/index_en.html SCF/CS/FLAV/FLAVOUR/4 ADD1 FINAL Opinion of the Scientific Committee on Food on Methyleugenol (4-Allyl-1,2-dimethoxybenzene) (adopted on 26 September 2001) Terms of reference The Committee is asked to advise the Commission on substances used as flavouring substances or present in flavourings or present in other food ingredients with flavouring properties for which existing toxicological data indicate that restrictions of use or presence might be necessary to ensure safety for human health. In particular, the Committee is asked to advise the Commission on the implications for human health of methyleugenol (4-allyl-1,2-dimethoxybenzene) in the diet. Introduction In 1999 methyleugenol was evaluated by the Committee of Experts on Flavouring Substances of the Council of Europe. The conclusions of this Committee were: "Available data show that methyleugenol is a naturally-occurring genotoxic carcinogen compound with a DNA-binding potency similar to that of safrole. Human exposure to methyleugenol may occur through the consumption of foodstuffs flavoured with aromatic plants and/or their essential oil fractions which contain methyleugenol.
  • Recreating Ancient Metabolic Pathways Before Enzymes Kamila B

    Recreating Ancient Metabolic Pathways Before Enzymes Kamila B

    Recreating ancient metabolic pathways before enzymes Kamila B. Muchowska, Elodie Chevallot-Beroux, Joseph Moran To cite this version: Kamila B. Muchowska, Elodie Chevallot-Beroux, Joseph Moran. Recreating ancient metabolic path- ways before enzymes. Bioorganic and Medicinal Chemistry, Elsevier, 2019, 27 (12), pp.2292-2297. 10.1016/j.bmc.2019.03.012. hal-02516541 HAL Id: hal-02516541 https://hal.archives-ouvertes.fr/hal-02516541 Submitted on 23 Mar 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Graphical Abstract To create your abstract, type over the instructions in the template box below. Fonts or abstract dimensions should not be changed or altered. Recreating ancient metabolic pathways Leave this area blank for abstract info. before enzymes Kamila B. Muchowskaa* , Elodie Chevallot-Berouxa, and Joseph Morana* University of Strasbourg, CNRS, ISIS UMR 7006, 67000 Strasbourg, France Bioorganic & Medicinal Chemistry journal homepage: www.elsevier.com Recreating ancient metabolic pathways before enzymes Kamila B. Muchowska,a* Elodie Chevallot-Beroux,a and Joseph Morana* a University of Strasbourg, CNRS, ISIS UMR 7006, 67000 Strasbourg, France. ARTICLE INFO ABSTRACT Article history: The biochemistry of all living organisms uses complex, enzyme-catalyzed metabolic reaction Received networks.
  • Analytical Chemistry in the 21St Century: Challenges, Solutions, and Future Perspectives of Complex Matrices Quantitative Analyses in Biological/Clinical Field

    Analytical Chemistry in the 21St Century: Challenges, Solutions, and Future Perspectives of Complex Matrices Quantitative Analyses in Biological/Clinical Field

    Review Analytical Chemistry in the 21st Century: Challenges, Solutions, and Future Perspectives of Complex Matrices Quantitative Analyses in Biological/Clinical Field 1, 2, 2, 3 Giuseppe Maria Merone y, Angela Tartaglia y, Marcello Locatelli * , Cristian D’Ovidio , Enrica Rosato 3, Ugo de Grazia 4 , Francesco Santavenere 5, Sandra Rossi 5 and Fabio Savini 5 1 Department of Neuroscience, Imaging and Clinical Sciences, University of Chieti–Pescara “G. d’Annunzio”, Via dei Vestini 31, 66100 Chieti, Italy; [email protected] 2 Department of Pharmacy, University of Chieti-Pescara “G. d’Annunzio”, Via Dei Vestini 31, 66100 Chieti (CH), Italy; [email protected] 3 Section of Legal Medicine, Department of Medicine and Aging Sciences, University of Chieti–Pescara “G. d’Annunzio”, 66100 Chieti, Italy; [email protected] (C.D.); [email protected] (E.R.) 4 Laboratory of Neurological Biochemistry and Neuropharmacology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Via Celoria 11, 20133 Milano, Italy; [email protected] 5 Pharmatoxicology Laboratory—Hospital “Santo Spirito”, Via Fonte Romana 8, 65124 Pescara, Italy; [email protected] (F.S.); [email protected] (S.R.); [email protected] (F.S.) * Correspondence: [email protected]; Tel.: +39-0871-3554590; Fax: +39-0871-3554911 These authors contributed equally to the work. y Received: 16 September 2020; Accepted: 16 October 2020; Published: 30 October 2020 Abstract: Nowadays, the challenges in analytical chemistry, and mostly in quantitative analysis, include the development and validation of new materials, strategies and procedures to meet the growing need for rapid, sensitive, selective and green methods.
  • Gravimetric Analysis

    Gravimetric Analysis

    Gravimetric Analysis Gravimetric Analysis can be used to determine the percent composition of a species in a compound. This is known as quantitative analysis. An agent (precipitating agent) is chosen which will cause the species of interest to precipitate out of solution. The precipitate is then isolated and weighed. Through a series of calculations, the amount of the species in the original sample or compound can then be determined. 1. Weigh accurately about 0.5 g of the unknown, and dissolve it in water. The volume of water is not important, but you do want to make sure the solid is completely dissolved. 2. Add the precipitating agent in the form of solution. For example, to precipitate a chloride use a soluble salt of silver (AgNO3). 3. Add the precipitating agent until no more solid seems to precipitate. Allow the mixture to sit for about 5 minutes, and then add a few drops more, observing to see if any more precipitation occurs. If you see more solid forming, keep repeating the steps until no more precipitate results. Now separate the solid from the liquid. The mixture can be filtered by vacuum filtration through a weighed filter paper. Other methods involve gravity filtration or use of a centrifuge. Allow the solid to dry until you get a constant weight for readings at subsequent times (at least overnight or through use of an oven). 4. From the mass of precipitated compound (ppt) and the formula (in this case AgCl), you can calculate the percent composition of a species (in this case Cl-) in the original sample.
  • "Thermal Analysis and Calorimetry," In

    "Thermal Analysis and Calorimetry," In

    Article No : b06_001 Thermal Analysis and Calorimetry STEPHEN B. WARRINGTON, Formerly Anasys, IPTME, Loughborough University, Loughborough, United Kingdom Gu€NTHER W. H. Ho€HNE, Formerly Polymer Technology (SKT), Eindhoven University of Technology, Eindhoven, The Netherlands 1. Thermal Analysis.................. 415 2.2. Methods of Calorimetry............. 424 1.1. General Introduction ............... 415 2.2.1. Compensation of the Thermal Effects.... 425 1.1.1. Definitions . ...................... 415 2.2.2. Measurement of a Temperature Difference 425 1.1.2. Sources of Information . ............. 416 2.2.3. Temperature Modulation ............. 426 1.2. Thermogravimetry................. 416 2.3. Calorimeters ..................... 427 1.2.1. Introduction ...................... 416 2.3.1. Static Calorimeters ................. 427 1.2.2. Instrumentation . .................. 416 2.3.1.1. Isothermal Calorimeters . ............. 427 1.2.3. Factors Affecting a TG Curve ......... 417 2.3.1.2. Isoperibolic Calorimeters ............. 428 1.2.4. Applications ...................... 417 2.3.1.3. Adiabatic Calorimeters . ............. 430 1.3. Differential Thermal Analysis and 2.3.2. Scanning Calorimeters . ............. 430 Differential Scanning Calorimetry..... 418 2.3.2.1. Differential-Temperature Scanning 1.3.1. Introduction ...................... 418 Calorimeters ...................... 431 2.3.2.2. Power-Compensated Scanning Calorimeters 432 1.3.2. Instrumentation . .................. 419 2.3.2.3. Temperature-Modulated 1.3.3. Applications ...................... 419 Scanning Calorimeters . ............. 432 1.3.4. Modulated-Temperature DSC (MT-DSC) . 421 2.3.3. Chip-Calorimeters .................. 433 1.4. Simultaneous Techniques............ 421 2.4. Applications of Calorimetry.......... 433 1.4.1. Introduction ...................... 421 2.4.1. Determination of Thermodynamic Functions 433 1.4.2. Applications ...................... 421 2.4.2. Determination of Heats of Mixing . .... 434 1.5. Evolved Gas Analysis..............
  • Ethanol Production from Hydrolyzed Kraft Pulp by Mono- and Co-Cultures of Yeasts: the Challenge of C6 and C5 Sugars Consumption

    Ethanol Production from Hydrolyzed Kraft Pulp by Mono- and Co-Cultures of Yeasts: the Challenge of C6 and C5 Sugars Consumption

    energies Article Ethanol Production from Hydrolyzed Kraft Pulp by Mono- and Co-Cultures of Yeasts: The Challenge of C6 and C5 Sugars Consumption Rita H. R. Branco, Mariana S. T. Amândio, Luísa S. Serafim and Ana M. R. B. Xavier * CICECO–Aveiro Institute of Materials, Chemistry Department, University of Aveiro, Campus Universitario de; Santiago, 3810-193 Aveiro, Portugal; [email protected] (R.H.R.B.); [email protected] (M.S.T.A.); luisa.serafi[email protected] (L.S.S.) * Correspondence: [email protected]; Tel.: +351-234-370-716 Received: 27 December 2019; Accepted: 4 February 2020; Published: 8 February 2020 Abstract: Second-generation bioethanol production’s main bottleneck is the need for a costly and technically difficult pretreatment due to the recalcitrance of lignocellulosic biomass (LCB). Chemical pulping can be considered as a LCB pretreatment since it removes lignin and targets hemicelluloses to some extent. Chemical pulps could be used to produce ethanol. The present study aimed to investigate the batch ethanol production from unbleached Kraft pulp of Eucalyptus globulus by separate hydrolysis and fermentation (SHF). Enzymatic hydrolysis of the pulp resulted in a glucose yield of 96.1 3.6% and a xylose yield of 94.0 7.1%. In an Erlenmeyer flask, fermentation of the ± ± hydrolysate using Saccharomyces cerevisiae showed better results than Scheffersomyces stipitis. At both the Erlenmeyer flask and bioreactor scale, co-cultures of S. cerevisiae and S. stipitis did not show significant improvements in the fermentation performance. The best result was provided by S. cerevisiae alone in a bioreactor, which fermented the Kraft pulp hydrolysate with an ethanol yield of 0.433 g g 1 and a volumetric ethanol productivity of 0.733 g L 1 h 1, and a maximum ethanol · − · − · − concentration of 19.24 g L 1 was attained.