DOCSLIB.ORG

Hydrolysis of Formamide and Volatilization of Ammonia from Nitrogen Fertilizers Added to Soils Heitor Cantarella Iowa State University

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Hydrolysis of Formamide and Volatilization of Ammonia from Nitrogen Fertilizers Added to Soils Heitor Cantarella Iowa State University Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1983 Hydrolysis of formamide and volatilization of ammonia from nitrogen fertilizers added to soils Heitor Cantarella Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Agricultural Science Commons, Agriculture Commons, and the Agronomy and Crop Sciences Commons Recommended Citation Cantarella, Heitor, "Hydrolysis of formamide and volatilization of ammonia from nitrogen fertilizers added to soils " (1983). Retrospective Theses and Dissertations. 7700. https://lib.dr.iastate.edu/rtd/7700 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This reproduction was made from a copy of a document sent to us for microfilming. While the most advanced technology has been used to photograph and reproduce this document, the quality of the reproduction is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help clarify markings or notations which may appear on this reproduction. 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure complete continuity. 2. When an image on the film is obliterated with a round black mark, it is an indication of either blurred copy because of movement during exposure, duplicate copy, or copyrighted materials that should not have been filmed. For blurred pages, a good image of the page can be found in the adjacent frame. If copyrighted materials were deleted, a target note will appear listing the pages in the adjacent frame. 3. When a map, drawing or chart, etc., is part of the material being photographed, a definite method of "sectioning" the material has been followed. It is customary to begin filming at the upper left hand comer of a large sheet and to continue from left to riglit in equal sections with small overlaps. If necessary, sectioning is continued again-beginning below the first row and continuing on until complete. 4. For illustrations that cannot be satisfactorily reproduced by xerographic means, photographic prints can be purchased at additional cost and inserted into your xerographic copy. These prints are available upon request from the Dissertations Customer Services Department. 5. Some pages in any document may have indistinct print. In all cases the best available copy has been filmed. Universi^ Micionlms International 300 N. Zeeb Road Ann Arbor, Ml 48106 8323269 Canta relia, Heitor HYDROLYSIS OF FORMAMIDE AND VOLATILIZATION OF AMMONIA FROM NITROGEN FERTILIZERS ADDED TO SOILS Iowa State University PH.D. 1983 University Microfilms IntsrnEltio nâl SOO N. Zeeb Road, Ann Arbor, Ml 48106 PLEASE NOTE: In all cases this material has been filmed in the best possible way from the available copy. Problems encountered with this document have been identified here with a check mark V . 1. Glossy photographs or pages 2. Colored illustrations, paper or print 3. Photographs with darl^ background 4. Illustrations are poor copy 5. Pages witii black marks, not origin^ copy 6. Print shows through as there is text on both sides of page 7. Indistinct, broken or small print on several pages \/ 8. Print exceeds margin requirements 9. Tightly bound copy with print lost in spine 10. Computer printout pages with indistinct print 11. Page(s) lacking when material received, and not available from school or author. 12. Page(s) seem to be missing in numbering only'as text follovrs. 13. Two pages numbered . Text follows. 14. Curling and wrinkled pages 15. Other Dissertation contains pages with print at a slant» filmed as receî ved. University Microfilms International Hydrolysis of formamide and volatilization of ammonia from nitrogen fertilizers added to soils by Heitor Cantarella A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Department: Agronomy Major: Soil Fertility Approved: Signature was redacted for privacy. In Charge of Major Work Signature was redacted for privacy. For^tHé^ Major Department Signature was redacted for privacy. For the Gradate College Iowa State University Ames, Iowa 1983 ii TABLE OF CONTENTS Page INTRODUCTION 1 LITERATURE REVIEW 5 Transformations of Amides in Soils 5 Methods of Analysis of Formamide 8 Formamide and Other Amides as Fertilizers 10 Volatilization of NH3 from N Fertilizers Applied to Soils 16 PART I. COLORIMETRIC DETERMINATION OF FORMAMIDE 42 INTRODUCTION 43 DESCRIPTION OF METHODS 46 Reagents 46 Procedure 47 RESULTS AND DISCUSSION 49 PART II. DETERMINATION OF FORMAMIDE ADDED TO SOILS 79 INTRODUCTION 80 MATERIALS AND METHODS 82 Materials 82 Reagents 82 Procedure 85 RESULTS AND DISCUSSION 87 iii Page PART III. HYDROLYSIS OF FORMAMU® ADDED TO SOILS 97 INTRODUCTION 98 MATERIALS AND METHODS 101 RESULTS AND DISCUSSION 103 PART IV. VOLATILIZATION OF AMMONIA FROM NITROGEN FERTILIZERS ADIBD TO SOILS 116 INTRODUCTION 117 MATERIALS AND METHODS 121 Materials 121 Ammonia Volatilization Chamber 121 Experimental Set-up 124 Description of Experiments 127 Chemical Analysis 132 RESULTS AND DISCUSSION 135 Ammonia Volatilization from Surface-Applied Fertilizers 135 Effect of Crop Residues and Placement of N Fertilizers on NHg Volatilization 159 Formamide Volatilization Following Its Application to Soils 186 SUMMARY AND CONCLUSIONS 192 LITERATURE CITED 198 ACKNOWLEDOIENTS 209 1 INTRODUCTION Aliphatic amides undergo enzymatic hydrolysis in soils, yielding NH^ and the corresponding carboxylic acids. Urea, which is also an amide, is one of the most commonly used N fertilizers. Several other compounds of the class of amides, including oxamide and formamide, have been shown to supply N to plants. Dry-matter yield and yield of N ob­ tained with amides as sources of N are usually similar to those obtained with conventional N fertilizers, such as urea and ammonium nitrate. Oxamide has low solubility in water. In soil, large granules of oxamide exhibit slow-release characteris­ tics, but the release of N from powdered oxamide is similar to that from soluble N sources such as ammonium nitrate, Formamide is liquid at room temperatures and is a good solvent for urea and many cimmonium salts, Formamide lowers the salting-out temperature of liquid mixtures and can be used to produce nonpressure liquid fertilizers of high N content. The fertilizer value of formamide was first recog­ nized in 1937. Since then, encouraging results with this compound have been obtained in both greenhouse and field experiments, Formamide is hydrolyzed in soils and the inorganic N produced accumulates as NO^ under aerobic conditions. How­ ever, studies on the course and rate of formamide hydrolysis 2 are hindered by the lack of a method of determination of formamide in soils. A method of analysis of formamide that seems suitable to be adapted to soil extracts involves the determination of traces of formamide colorimetrically by the hydroxamic acid-ferric complex formed from the reaction of Fe , in an acidic medium, vith the formohydroxamic acid produced from the reaction of formamide with hydroxy lamine under alkaline conditions. This method is relatively simple and rapid, and has the advantage that it is not subject to interference by the products of formamide hydrolysis in soils. Liquid fertilizers are most commonly employed for sur­ face application to soils. Fertilizers containing or produc­ ing NH^ are subject to NHg volatilization losses, especially if they are surface applied to calcareous soils". Surface application of these fertilizers is desirable if the com­ pounds produce an acid reaction upon dissolution and are applied on neutral or acid soils; however, fertilizers such as urea, which, upon hydrolysis, can cause substantial in­ creases in the soil pH around the fertilizer particle, are susceptible to NHg losses if surface applied even to acid soils. Ammonia volatilization losses from N fertilizers are enhanced by high soil pH, high soil temperature, high rates of fertilizer application, and by conditions that favor the drying process in the soil. Higher NH^ volatilization losses are observed from fertilizers applied to sandy than to heavy- 3 textured, high-CEC soils. Ammonia losses are reduced by- rainfall, irrigation, or mechanical incorporation of the surface-applied N fertilizers. Information available in the literature indicates that crop recovery of N is lower from surface-applied than from soil-incorporated oxamide and formamide, suggesting that volatilization losses, presumably as NH^, may occur. However, no direct measurements of NH^ volatilized from oxamide applied to soils have been made. The little information available on NH^ volatilization from formamide indicates that NHg does evolve from soils treated with surface-applied formamide and that the amount of NH^ lost increases with the increase in the rate of application and decreases with the increase in the CEC of the soil. If the potential of oxamide and formamide
Load more

Recommended publications
  • Interstellar Formamide (NH2CHO), a Key Prebiotic Precursor
    Interstellar formamide (NH2CHO), a key prebiotic precursor Ana López-Sepulcre,∗,y,z Nadia Balucani,{ Cecilia Ceccarelli,y Claudio Codella,x,y François Dulieu,k and Patrice Theulé? yUniv. Grenoble Alpes, IPAG, F-38000 Grenoble, France zInstitut de Radioastronomie Millimétrique (IRAM), 300 rue de la piscine, F-38406 Saint-Martin d’Hères, France {Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, I-06123 Perugia, Italy xINAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze, Italy kUniversité de Cergy-Pontoise, Observatoire de Paris, PSL University, Sorbonne Université, CNRS, LERMA, F-95000, Cergy-Pontoise, France ?Aix-Marseille Université, PIIM UMR-CNRS 7345, 13397 Marseille, France E-mail: [email protected] Abstract Formamide (NH2CHO) has been identified as a potential precursor of a wide variety arXiv:1909.11770v1 [astro-ph.SR] 25 Sep 2019 of organic compounds essential to life, and many biochemical studies propose it likely played a crucial role in the context of the origin of life on our planet. The detection of formamide in comets, which are believed to have –at least partially– inherited their current chemical composition during the birth of the Solar System, raises the question whether a non-negligible amount of formamide may have been exogenously delivered onto a very young Earth about four billion years ago. A crucial part of the effort to 1 answer this question involves searching for formamide in regions where stars and planets are forming today in our Galaxy, as this can shed light on its formation, survival, and chemical re-processing along the different evolutionary phases leading to a star and planetary system like our own.
    [Show full text]
  • KINETICS of HYDROLYSIS of ACETIC ANHYDRIDE by IN-SITU FTIR SPECTROSCOPY an Experiment for the Undergraduate Laboratory
    .tA... 5-4._l_a_b _o_r._a_t_o_r.:.y________ ) KINETICS OF HYDROLYSIS OF ACETIC ANHYDRIDE BY IN-SITU FTIR SPECTROSCOPY An Experiment for the Undergraduate Laboratory SHAKER HA.JI, CAN ERKEY University of Connecticut • Storrs, CT 06269-3222 he senior-level chemical engineering undergraduate laboratory course at the University of Connecticut con­ 2 T sists of two four-hour labs per week, during which groups of three to four students typically perform five ex­ Quite a few studies have been reported in the literature on the 2 periments during the course of the semester. Each experi­ kinetics of hydrolysis of acetic anhydride. [J, A,5l Eldridge and ment is studied for either one or two weeks, depending on its Piretl41 obtained the pseudo-first-order reaction rate constant complexity and the scale of the equipment. The students are using a batch reactor. To determine the acetic anhydride con­ given only the general goals for each experiment and are re­ centration, samples from the reactor were withdrawn into tared quired to define their own objectives, to develop an experi­ flasks containing 15-20 times the quantity of saturated aniline­ mental plan, to prepare a pre-lab report (including a discus­ water required to react with the sample. Since the anhydride sion of safety measures), to perform the experiments and ana­ rapidly acetylates the aniline, producing acetanilide and ace­ lyze the data, and to prepare group or individual written and/ tic acid, the samples were then titrated to determine the con­ or oral reports. centration of acetic acid. In another study, Shatyski and One or two of the experiments in this course involve reac­ Hanesianrsi determined the kinetics of the above reaction by tion kinetics.
    [Show full text]
  • Citric Acid Cycle
    CHEM464 / Medh, J.D. The Citric Acid Cycle Citric Acid Cycle: Central Role in Catabolism • Stage II of catabolism involves the conversion of carbohydrates, fats and aminoacids into acetylCoA • In aerobic organisms, citric acid cycle makes up the final stage of catabolism when acetyl CoA is completely oxidized to CO2. • Also called Krebs cycle or tricarboxylic acid (TCA) cycle. • It is a central integrative pathway that harvests chemical energy from biological fuel in the form of electrons in NADH and FADH2 (oxidation is loss of electrons). • NADH and FADH2 transfer electrons via the electron transport chain to final electron acceptor, O2, to form H2O. Entry of Pyruvate into the TCA cycle • Pyruvate is formed in the cytosol as a product of glycolysis • For entry into the TCA cycle, it has to be converted to Acetyl CoA. • Oxidation of pyruvate to acetyl CoA is catalyzed by the pyruvate dehydrogenase complex in the mitochondria • Mitochondria consist of inner and outer membranes and the matrix • Enzymes of the PDH complex and the TCA cycle (except succinate dehydrogenase) are in the matrix • Pyruvate translocase is an antiporter present in the inner mitochondrial membrane that allows entry of a molecule of pyruvate in exchange for a hydroxide ion. 1 CHEM464 / Medh, J.D. The Citric Acid Cycle The Pyruvate Dehydrogenase (PDH) complex • The PDH complex consists of 3 enzymes. They are: pyruvate dehydrogenase (E1), Dihydrolipoyl transacetylase (E2) and dihydrolipoyl dehydrogenase (E3). • It has 5 cofactors: CoASH, NAD+, lipoamide, TPP and FAD. CoASH and NAD+ participate stoichiometrically in the reaction, the other 3 cofactors have catalytic functions.
    [Show full text]
  • Biotransformation: Basic Concepts (1)
    Chapter 5 Absorption, Distribution, Metabolism, and Elimination of Toxics Biotransformation: Basic Concepts (1) • Renal excretion of chemicals Biotransformation: Basic Concepts (2) • Biological basis for xenobiotic metabolism: – To convert lipid-soluble, non-polar, non-excretable forms of chemicals to water-soluble, polar forms that are excretable in bile and urine. – The transformation process may take place as a result of the interaction of the toxic substance with enzymes found primarily in the cell endoplasmic reticulum, cytoplasm, and mitochondria. – The liver is the primary organ where biotransformation occurs. Biotransformation: Basic Concepts (3) Biotransformation: Basic Concepts (4) • Interaction with these enzymes may change the toxicant to either a less or a more toxic form. • Generally, biotransformation occurs in two phases. – Phase I involves catabolic reactions that break down the toxicant into various components. • Catabolic reactions include oxidation, reduction, and hydrolysis. – Oxidation occurs when a molecule combines with oxygen, loses hydrogen, or loses one or more electrons. – Reduction occurs when a molecule combines with hydrogen, loses oxygen, or gains one or more electrons. – Hydrolysis is the process in which a chemical compound is split into smaller molecules by reacting with water. • In most cases these reactions make the chemical less toxic, more water soluble, and easier to excrete. Biotransformation: Basic Concepts (5) – Phase II reactions involves the binding of molecules to either the original toxic molecule or the toxic molecule metabolite derived from the Phase I reactions. The final product is usually water soluble and, therefore, easier to excrete from the body. • Phase II reactions include glucuronidation, sulfation, acetylation, methylation, conjugation with glutathione, and conjugation with amino acids (such as glycine, taurine, and glutamic acid).
    [Show full text]
  • 15 Aug 2017 Sims Ue2,2021 23, June Srnm Astrophysics & Astronomy .Codella C
    Astronomy & Astrophysics manuscript no. codella˙astroph˙solisIII c ESO 2021 June 23, 2021 Letter to the Editor Seeds of Life in Space (SOLIS) III. Formamide in protostellar shocks: evidence for gas-phase formation C. Codella1, C. Ceccarelli2,1, P. Caselli3, N. Balucani4,1, V. Barone5, F. Fontani1, B. Lefloch2, L. Podio1, S. Viti6, S. Feng3, R. Bachiller7, E. Bianchi1,8, F. Dulieu9, I. Jim´enez-Serra10, J. Holdship6, R. Neri11, J. Pineda3, A. Pon12, I. Sims13, S. Spezzano3, A.I. Vasyunin3,14, F. Alves3, L. Bizzocchi3, S. Bottinelli15,16, E. Caux15,16, A. Chac´on-Tanarro3, R. Choudhury3, A. Coutens6, C. Favre1,2, P. Hily-Blant2, C. Kahane2, A. Jaber Al-Edhari2,17, J. Laas3, A. L´opez-Sepulcre11, J. Ospina2, Y. Oya18, A. Punanova3, C. Puzzarini19, D. Quenard10, A. Rimola20, N. Sakai21, D. Skouteris5, V. Taquet22,1, L. Testi23,1, P. Theul´e24, P. Ugliengo25, C. Vastel15,16, F. Vazart5, L. Wiesenfeld2, and S. Yamamoto18 1 INAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy 2 Univ. Grenoble Alpes, CNRS, Institut de Plan´etologie et d’Astrophysique de Grenoble (IPAG), 38000 Grenoble, France 3 Max-Planck-Institut f¨ur extraterrestrische Physik (MPE), Giessenbachstrasse 1, 85748 Garching, Germany 4 Dipartimento di Chimica, Biologia e Biotecnologie, Via Elce di Sotto 8, 06123 Perugia, Italy 5 Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy 6 Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK 7 IGN, Observatorio Astron´omico Nacional, Calle Alfonso XII, 28004 Madrid, Spain 8 Dipartimento di Fisica e Astronomia, Universit`adegli Studi di Firenze, Italy 9 LERMA, Universit´ede Cergy-Pontoise, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universit´e, UPMC, Univ.
    [Show full text]
  • LIQUID DYNE PENS (#N001-002, #N001-015) Date Prepared: 5/1/03
    *** MATERIAL SAFETY DATA SHEET *** DYNE SOLUTION-100CC (#N001-011), LIQUID DYNE PENS (#N001-002, #N001-015) Date Prepared: 5/1/03 SECTION A DISTRIBUTOR: UV PROCESS SUPPLY, INC 1229 W. CORTLAND ST. CHICAGO, IL 60614-4805 TELEPHONE: (773)248-0099 EMERGENCY #: (800)424-9300 SECTION B GENERAL PRODUCT INFORMATION PRODUCT NAME: CON-TROL-CURE DYNE TEST SOLUTIONS CON-TROL-CURE LIQUID DYNE PEN SET FORM: Liquid COLOR: Medium blue ODOR: Mild, non-residual; ethereal/ammoniacal SECTION C COMPOSITION/INGREDIENTS Constituent CAS No. Molecular Formula 2-ethoxyethanol, 100% pure (C)* 110-80-5 C2H5OC2H4OH Formamide, minimum 99.5% pure (F)** 75-12-7 HCONH2 Water (H) 7732-18-5 H2O Victoria Blue Dye, 100% pure 2185-86-6 no data *2-ethoxyethanol is also known as ethylene glycol monoethyl ether, cellosolve solvent, ehlyl cellosolve, and glycol ether EE. **Formamide is also known as methanamide. Mix Percentages by Dyne Level Level C (vol) F (vol) Level C (vol) F (vol) Level F (vol) H (vol) 30 100.0% 0.0% 44 22.0% 78.0% 57 100.0% 0.0% 31 97.5% 2.5% 45 19.7% 80.3% 58 81.2% 18.8% 32 89.5% 10.5% 46 17.2% 82.8% 59 73.1% 26.9% 33 81.0% 19.0% 47 15.0% 85.0% 60 65.0% 35.0% 34 73.5% 26.5% 48 13.0% 87.0% 61 56.0% 44.0% 35 65.0% 35.0% 49 11.1% 88.9% 62 47.0% 53.0% 36 57.5% 42.5% 50 9.3% 90.7% 63 38.8% 61.2% 37 51.5% 48.5% 51 7.8% 92.2% 64 30.6% 69.4% 38 46.0% 54.0% 52 6.3% 93.7% 65 24.4% 75.6% 39 41.0% 59.0% 53 4.9% 95.1% 66 18.2% 81.8% 40 36.5% 63.5% 54 3.5% 96.5% 67 13.4% 86.6% 41 32.5% 67.5% 55 2.2% 97.8% 68 8.6% 91.4% 42 28.5% 71.5% 56 1.0% 99.0% 69 6.1% 93.9% 43 25.3% 74.7% 70 3.6% 96.4% Concentration of Victoria Blue dye is 0.3 grams per liter.
    [Show full text]
  • Two-Stage, Dilute Sulfuric Acid Hydrolysis of Hardwood for Ethanol Production
    TWO-STAGE, DILUTE SULFURIC ACID HYDROLYSIS OF HARDWOOD FOR ETHANOL PRODUCTION John F. Harris, B.S. Chemical Engineer Andrew J. Baker, B.S. Chemical Engineer John I. Zerbe, Ph.D. Program Manager Energy Research, Development, and Application Forest Products Laboratory, Forest Service, USDA Madison, Wisconsin53705 ABSTRACT The Forest Products Laboratory has developed fundamental kinetic relationships for the hydrolysis of lignocellulose dating back to World War II. Recent work at the Laboratory has provided additional informa­ tion on hydrolysis of red oak by a two-stage process at higher tempera­ tures with lower liquid-to-solid ratios. The complications of working with mixtures of sugars and acetic acid (6 percent of oak) are such that effective fractionation is necessary. This is best accomplished by prehydrolysis using dilute sulfuric acid. Dilute acid hydrolysis is also currently the best method for conversion of the residual prehydro­ lyzed lignocellulose to glucose. The course and yield of reactions are well predicted by kinetics data, but more attention needs to be given to the effects of ash constituents on the catalyst acid and the rever­ sion reaction, and in reducing the water-to-wood ratio in hydrolysis. The purity of the solutions generated by the two-stage process is considerably better than that obtained by the previous percolation process, but this advantage is offset somewhat by the higher yields of the percolation process. Projections on the economics of the two-stage process, although better than for processes based on prior technology, are still considered high risk. 1151 TWO-STAGE, DILUTE SULFURIC ACID HYDROLYSIS OF HARDWOOD FOR ETHANOL PRODUCTION INTRODUCTION Interest in wood hydrolysis dates to 1819 when Braconnot dis­ covered that cellulose could be dissolved in concentrated acid solutions and converted to sugar.
    [Show full text]
  • TR-541: Formamide (CASRN 75-12-7) in F344/N Rats and B6C3F1 Mice (Gavage Studies)
    NTP TECHNICAL REPORT ON THE TOXICOLOGY AND CARCINOGENESIS STUDIES OF FORMAMIDE (CAS NO. 75-12-7) IN F344/N RATS AND B6C3F1 MICE (GAVAGE STUDIES) NATIONAL TOXICOLOGY PROGRAM P.O. Box 12233 Research Triangle Park, NC 27709 July 2008 NTP TR 541 NIH Publication No. 08-5884 National Institutes of Health Public Health Service U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES FOREWORD The National Toxicology Program (NTP) is an interagency program within the Public Health Service (PHS) of the Department of Health and Human Services (HHS) and is headquartered at the National Institute of Environmental Health Sciences of the National Institutes of Health (NIEHS/NIH). Three agencies contribute resources to the program: NIEHS/NIH, the National Institute for Occupational Safety and Health of the Centers for Disease Control and Prevention (NIOSH/CDC), and the National Center for Toxicological Research of the Food and Drug Administration (NCTR/FDA). Established in 1978, the NTP is charged with coordinating toxicological testing activities, strengthening the science base in toxicology, developing and validating improved testing methods, and providing information about potentially toxic substances to health regulatory and research agencies, scientific and medical communities, and the public. The Technical Report series began in 1976 with carcinogenesis studies conducted by the National Cancer Institute. In 1981, this bioassay program was transferred to the NTP. The studies described in the Technical Report series are designed and conducted to characterize and evaluate the toxicologic potential, including carcinogenic activity, of selected substances in laboratory animals (usually two species, rats and mice). Substances selected for NTP toxicity and carcinogenicity studies are chosen primarily on the basis of human exposure, level of production, and chemical structure.
    [Show full text]
  • The Hydrolysis of Phosphinates and Phosphonates: a Review
    molecules Review The Hydrolysis of Phosphinates and Phosphonates: A Review Nikoletta Harsági and György Keglevich * Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, 1521 Budapest, Hungary; [email protected] * Correspondence: [email protected]; Tel.: +36-1-463-1111 (ext. 5883) Abstract: Phosphinic and phosphonic acids are useful intermediates and biologically active com- pounds which may be prepared from their esters, phosphinates and phosphonates, respectively, by hydrolysis or dealkylation. The hydrolysis may take place both under acidic and basic conditions, but the C-O bond may also be cleaved by trimethylsilyl halides. The hydrolysis of P-esters is a challenging task because, in most cases, the optimized reaction conditions have not yet been explored. Despite the importance of the hydrolysis of P-esters, this field has not yet been fully surveyed. In order to fill this gap, examples of acidic and alkaline hydrolysis, as well as the dealkylation of phosphinates and phosphonates, are summarized in this review. Keywords: hydrolysis; dealkylation; phosphinates; phosphonates; P-acids 1. Introduction Phosphinic and phosphonic acids are of great importance due to their biological activity (Figure1)[ 1]. Most of them are known as antibacterial agents [2,3]. Multidrug- resistant (MDR) and extensively drug-resistant (XDR) pathogens may cause major problems Citation: Harsági, N.; Keglevich, G. in the treatment of bacterial infections. However, Fosfomycin has remained active against The Hydrolysis of Phosphinates and both Gram-positive and Gram-negative MDR and XDR bacteria [2]. Acyclic nucleoside Phosphonates: A Review. Molecules phosphonic derivatives like Cidofovir, Adefovir and Tenofovir play an important role 2021, 26, 2840.
    [Show full text]
  • OXAMYL (126) First Draft Prepared by Ursula Banasiak, Federal Biological Research Centre for Agriculture and Forestry (BBA), Kleinmachnow, Germany
    1007 OXAMYL (126) First draft prepared by Ursula Banasiak, Federal Biological Research Centre for Agriculture and Forestry (BBA), Kleinmachnow, Germany EXPLANATION Oxamyl was listed by the 1997 CCPR (29th Session, ALINORM 97/24A) for periodic re-evaluation for residues by the 2002 JMPR. IDENTITY ISO common name: oxamyl Chemical name IUPAC: N,N-dimethyl-2-methylcarbamoyloxyimino-2-(methylthio)acetamide CAS: methyl 2-(dimethylamino)-N-[[(methylamino)carbonyl]oxy]-2-oxoethanimidothioate CAS Registry No: 23135-22-0 CIPAC No: 342 Synonyms: DPX-D1410, oxamil Structural formula: CH3 S H 3 C N O N O H 3 C O NH H 3 C Molecular formula: C7H13N3O3S Molecular weight: 219.3 Physical and chemical properties Pure active ingredient Appearance: White crystalline solid (Tuffy, 2000a) Vapour pressure (at 25°C): 5.12 x 10-5 Pa (Barefoot, 1989a) Henry’s law constant (at 25°C): 3.96 x 10-8 Pa m3 x mol-1 (Barefoot, 1989b) Melting point: 99.8°C (Silveira, 1988) Octanol/water partition coefficient (at 25°C): 0.36 (Melander, 1988) Solubility in water (at 25°C): 28.2 g/100 g (Hoffmann, 1988) Solubility in organic solvents (at 20°C): acetone: >250 g/kg dichloromethane: >250 g/kg methanol: >250 g/kg n-heptane: 10.5 mg/l ethyl acetate: 4.13 x 104 mg/l 1008 oxamyl o-xylene: 3.14 x 103 mg/l (Hansen, 2000) Relative density: 1.313 g/cm3 (1313 kg/m3) (Tuffy, 2000b) Hydrolysis (half-life at 25°C): pH 5: <31 days, pH 7: 7.9 days, pH 9: 0.12 days (McNally and Wheeler, 1988a) Photolysis (half-life at 25°C): 7 days (McNally and Wheeler, 1988b) Technical material Appearance: no information.
    [Show full text]
  • Dithiooxamide As an Analytical Reagent
    DITHIOOXAMIDB AS AH ANALYTICAL HKAGJSHT by OHLANi) WILLIAM KOLLING B* A«, Prlends University, 1948 M. A,, Washington University, 1950 A TBSBIE submitted in partial fulfillment of the requirements for the degree MASTEfi Oy eCISNCB Department of Chemistry KANSAS STATE COLLEGS OP AGHICULTUi'ia AND APPLIED iiCUBOB 1958 L9 2 bQ>S ii acu^eA^f S SAILS OF CONTMTS INTHODUCTION 1 AHALITIOAL APPLICATIOITS OF RDBIAHIC ACID 4 fiUBBAHIC ACID AS AH ACID IN A^UBOUS AND NOHAQUBOUS MEDIA. 7 Method of Back and fJteenberg 7 Bvalurition of K„, K ^, and Molar Solubility by the Method of Back and Steenberg 9 Direct Determination of Molar Solubility as a Function of Ionic Strength 10 Squilibria In Dimethylformamide and Methanol 12 Experimental Details. ••••••••.. 16 Results and Discussion • 17 Determination of the libctinction Coefficients for Band Peaks •....••.•.•• 30 RBAOTION OF DITHIOOXAMIDB ACID WITH METALLIC IONS 39 Copper Rubeanate •••• ••••••••••• 39 qualitative Solubility in Various Organic Solvents. 39 Evaluation of the Molar Solubility of Copper ttubeanate in Aqueous Solution.. 4-2 Cobalt and Nickel Rubeanates 43 Solubility in Organic Solvents . 48 v^uantitotive Determination of the Solubility of Cobalt and Nickel Rubeanates •.•••••.•• 50 Structures for the Rubeanates •• 52 SUMMARY 57 ACKHOWLBDGMiafT 60 BIBLIOGRAPHY 61 .jd • » imROJliOTlOM Slthiooxamide, which is coniuonly called rubeanic acid, ie a weakly acidic compound, capable of chelate formation with a nuiaber of aetallic ions* Presiisiablj, the acidic character of rubeanic acid is attributable to the tautosierissi existing be- tween the diamido (base)| aoidoiaido (se£ii-acid), and dliaido (acid) forms (12) S - C-HHo W>-Q » RH HS-C » M 1 2 -V 1 -> , S-C-NHp^ S.C--NH2 ilS-C - HH H ^ + - » HH S-G ml" rs-C 7h^ S-C— HH^ ^ HS-C « NH n ^_ » Nil S-C +H^ S-C « NH It follows from these equilibria that to increase the con- centration of the rubeanate ion, removal of hydrogen ion is re- quired, and that as an analytical reagent rubeanic acid is most sensitive in basic solutions.
    [Show full text]
  • Drug Metabolism a Fascinating Link Between Chemistry and Biology
    GENERAL ARTICLE Drug Metabolism A Fascinating Link Between Chemistry and Biology Nikhil Taxak and Prasad V Bharatam Drug metabolism involves the enzymatic conversion of thera- peutically important chemical species to a new molecule inside the human body. The process may result in pharmaco- logically active, inactive, or toxic metabolite. Drug metabolic process involves two phases, the occurrence of which may vary from compound to compound. In this article, we discuss Nikhil is a DST Inspire the basics of drug metabolism, the process, metabolising Fellow and is pursuing PhD in NIPER, Mohali. organs and enzymes (especially CYP450) involved, chemistry His research pertains to behind metabolic reactions, importance, and consequences drug metabolism and with several interesting and significant examples to epitomize toxicity. His hobbies the same. We also cover the factors influencing the process of include playing table tennis and reading novels. drug metabolism, structure–toxicity relationship, enzyme in- duction and inhibition. Prasad V Bharatam is a Professor in Medicinal Chemistry in NIPER, 1. Introduction Mohali. He is interested in areas of theoretical Medicines are required for humans to cure diseases but at the chemistry, drug metabo- same time, they are foreign objects to the body. Hence, the human lism, diabetes, malaria and body tries to excrete them at the earliest. It is highly desirable that synthetic chemistry. the medicines get eliminated from the human body immediately after showing their drug action. The longer time the drug spends in the body, the greater are its side effects. The human body has a natural mechanism to eliminate these foreign objects (medi- cines). This is mainly facilitated by the process known as drug metabolism.
    [Show full text]