DOCSLIB.ORG

Complexometric Titration and Atomic Emission Spectroscopy) That Allow Us to Quantify the Amount of Each Metal Present Individually

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Complexometric Titration and Atomic Emission Spectroscopy) That Allow Us to Quantify the Amount of Each Metal Present Individually Title Quantitative Analysis of a Solution Containing Cobalt and Copper Name Manraj Gill (Lab partner: Tanner Adams) Abstract In this series of experiments, we determine the concentrations of two metal species, copper and cobalt, in a mixture of the two by initially using an ion exchange column to separate them from the mixture. We consequently use two different techniques (complexometric titration and atomic emission spectroscopy) that allow us to quantify the amount of each metal present individually. This step-by-step analysis not only goes through the basis for the experimental approach but also is a breakdown of the measurements that leads us to the final results: the Co:Cu ratio in the unknown mixture. Purpose In this series of three experiments (Parts I – III), we aim to initially separate a solution containing a mixture of Cobalt, Co (II), and Copper, Cu (II), ions in an unknown ratio and in unknown concentrations. The end goal of the entire experiment is to determine how much Co and Cu were originally present in the sample we obtained in Part I. But to do so, as explained in further detail in the ‘Theory and Methods’ section below, we initially separate the two ions (Part I) based on their unique chemical properties and then we attempt to quantify the separated ions through two different methods (Parts II, III). The overall purpose is an analysis of the efficiency of the separation and quantification approaches used to measure the constituent compounds in a mixture. This “efficiency” can be determined by comparing the obtained measurements to the known amounts that were used to make the solution. Theory and Methods (Part I) In order to initially separate the two ions from each other and obtain a purified amount of each of Cu and Co, we pass the unknown solution through an Ion Exchange Chromatograph. The principle of Ion Exchange Chromatography is based on utilizing an ion exchange resin. In this case, we use an anion exchange resin, namely, AG 1-X8. AG (analytical grade) 1-X8 is a strongly basic anion exchange resin with quaternary ammonium function groups attached to the styrene divinylbenzene copolymer lattice. (1) 1-X8 specifically has a high amount of resin cross-linkage making it suitable for exchange with and separation of low molecular weight inorganic anions! (1) The basis for using an anion exchange is to exploit the different number of chlorine ions (Cl-) that can be bound to the two different metal atoms. And then, the consequently different affinities to the Cl- bound metals to the resin serve to provide enough of a separation between the two if the resin vessel is tall enough. The strength with which an ion is held in the resin increases with increasing charge on the ion. Therefore, the more Cl- bound, the longer it stays in the resin. Now, to understand the theory of different amounts of chlorine ions being bound to the two metals, we look at the stability constants for metal-chloro complexes and find that, at specific concentrations of chrloide ion, there are different fractional distribution curves for the copper-chloride complexes and cobalt-chloride complexes. Therefore, we use the specific chloride concentration that yields in the metals being bound to significantly different number of chloride ions. This is characterized by looking at the stepwise stability constants. That is, the stability of the complex upon addition of another chloride. The equation can be written as follows: n+ - m+ M + bCl ⇌ MClb In the equation, the b value is the number of Cl- ions and the M is representative of either Cu or Co. The corresponding equilibrium constants as b varies from 0 (no chloride ions bound) to 4 (4 chloride ions bound) allows us to extrapolate the likelihood of the complex being present at specific concentrations of chloride. The graphs on the left plot out the distribution of a complex (based on the b values) at a range of chloride concentrations. And as stated previously, the property we want to exploit is the different number of chlorides that can be bound to the two metals at the same concentration of chloride ions. As marked on the plots, at pCl- = 0.5 (yellow line), [Cl-] = 3.0M, the copper complexes are present in highly chloride bound states (b = 2, 3, 4) whereas the cobalt complexes are less likely to be bound to chloride ions (b = 0, 1). Therefore, at this concentration of chloride ions, the copper will be retained more strongly in the resin while the cobalt will “run through” faster. Application of Theory (Part I) Based on the approach described above, we were able to use 3M HCl in the resin and separate the mixture of Co (II) and Cu (II) in the unknown sample. We had Unknown #2 and from 3 milliliters of the unknown solution, collected 3 samples each of copper and cobalt. Theory and Methods (Part II) In this second part of the series of experiments conducted, we focus only on the cobalt solution that was purified from Part I. The focus is on quantifying the amount of cobalt that was initially present in Unknown #2. To do this, we titrate the 3 separated cobalt solutions to determine with some level of statistical certainty, the amount of cobalt that was initially present. Acid-base titrations are done by neutralizing an acid with a base (or vice-versa). Potentiometric titrations are performed by measuring changes in voltage as compounds precipitate out. However, in the case of titrating out metals such as cobalt, we perform a complexometric titration. In a complexometric titration, the metal ions react with chelating agents to create a complex and an evident color change can be used to determine the end-point of a complexometric titration. (2) In the determination of metal ions, polydentate ligands are used. A polydentate ligand has more than 2 donor atoms that are used to bind to a central metal ion or atom. (3) The process of polydentate ligands binding to the metal ion and forming a complex (chelate) is called chelation. (3) And in such a case, the polydentate ligand is called a chelating agent. In this experiment, we use a chelating agent called ethylenediaminetetraaceic acid (EDTA). It is a polydentate ligand because it can form up to six bonds with the metal ion upon chelation. However, a “regular” titration whereby the metal solution is titrated with the solution of a known concentration of EDTA is difficult to perform. This is because a “regular” or direct titration requires fast course of reaction. That is, the complex formation must be fast enough. (2) Therefore, we perform a “back” titration to measure the amount of cobalt present. In this case, we add a known amount of EDTA of a known concentration to our cobalt solution. The added moles of EDTA are in excess of the predicted moles of metal in the solution. And the solution is mixed very well to ensure that complete chelation is allowed for. We then “back-titrate” by gradually adding cobalt solution of a known concentration until the indicator changes color. At the end-point/equivalence point (when the color changes), the number of moles of EDTA would be equal to the total number of moles of cobalt present. Therefore, the initial number of moles of cobalt is the difference! The chemical basis of the indicator used in this reaction is as follows. The compound, thiocyanate ion, is added that reacts with a free cobalt species and turns blue. Therefore, as long as any cobalt solution (from the standard stock) is still chelating and not free to react with thiocyanate, the solution will not turn blue. Upon turning blue, we will know that the number of moles of cobalt has just gone to a level where it is more than the number of moles of EDTA present. The lighter the hue of the blue, the lower the solution is post the equivalence point. Therefore, we attempt to identify the lightest hue of blue so that we are as close to the equivalence point as possible. Application of Theory (Part II) The concentration of EDTA used is 0.03063M and the concentration of the standard solution of cobalt (used for the titration) is 9.26163mg/mL. However, the stock solution is accurately diluted 10x to obtain a final concentration of ~0.9mg/mL. Since this dilution was performed and involves some degree of error associated with the volumetric transfer and the use of volumetric flasks, an initial standardization is performed which allows us to accurately know this concentration of the 10x diluted cobalt standard solution! The results from the standardization can be analyzed as follows: 10.00mL EDTA x 0.03063moles/L EDTA x 1L/1000mL = 3.063 x 10-4 moles EDTA Since 10.00ml of the diluted Co2+ standard was initially added. And since 7.75ml of this was actually added to reach equivalence, to calculate the concentration of the cobalt standard, we perform the following calculations: (3.063 x 10-4 moles Co2+) / (17.75mL Co2+) = (1.7256 x 10-5 moles/mL Co2+) x (58.93g/mol Co2+) = (1.0169 x 10-3 g/mL Co2+) x 1000mg/g = 1.016916mg/mL This varies from the 0.926163mg/mL expected. A ~10% difference. But this difference largely comes from the major error associated with not having a quantitative measurement of the equivalence point, but a visual one. Rather than relying on potentiometric voltage changes or pH changes as in the previous titration experiments, we use a visual end-point indicator. That leads to us basing the equivalence point on a hue of blue that might actually be very far past the actual equivalence point.
Load more

Recommended publications
  • Chemistry Grade Level 10 Units 1-15
    COPPELL ISD SUBJECT YEAR AT A GLANCE ​ ​ ​ ​​ ​ ​​ ​ ​ ​ ​ ​ ​ GRADE HEMISTRY UNITS C LEVEL 1-15 10 Program Transfer Goals ​ ​ ​ ​ ● Ask questions, recognize and define problems, and propose solutions. ​ ​​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ● Safely and ethically collect, analyze, and evaluate appropriate data. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ● Utilize, create, and analyze models to understand the world. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ● Make valid claims and informed decisions based on scientific evidence. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ● Effectively communicate scientific reasoning to a target audience. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ PACING 1st 9 Weeks 2nd 9 Weeks 3rd 9 Weeks 4th 9 Weeks ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6 Unit Unit Unit Unit Unit Unit Unit Unit Unit ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7 8 9 10 11 12 13 14 15 1.5 wks 2 wks 1.5 wks 2 wks 3 wks 5.5 wks ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1.5 2 2.5 2 wks 2 2 2 wks 1.5 1.5 ​ ​ ​ ​ wks wks wks wks wks wks wks Assurances for a Guaranteed and Viable Curriculum ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Adherence to this scope and sequence affords every member of the learning community clarity on the knowledge and skills ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ on which each learner should demonstrate proficiency. In order to deliver a guaranteed and viable curriculum, our team ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ commits to and ensures the following understandings: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shared Accountability: Responding
    [Show full text]
  • 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.
    [Show full text]
  • Titration Endpoint Challenge
    Analytical and Bioanalytical Chemistry (2019) 411:1–2 https://doi.org/10.1007/s00216-018-1430-y ANALYTICAL CHALLENGE Titration endpoint challenge Diego Alejandro Ahumada Forigua1 & Juris Meija2 Published online: 1 January 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 We would like to invite you to participate in the Analytical practical aspects related to the sources of uncertainty of Challenge, a series of puzzles to entertain and challenge our this technique. readers. This special feature of “Analytical and Bioanalytical Origins of titrimetry date back to 1690s, when Wilhelm Chemistry” has established itself as a truly unique quiz series, Homberg (1652–1715) published the first report related to with a new scientific puzzle published every three months. an acidity measurement [1]. Several decades later Claude Readers can access the complete collection of published prob- Geoffroy (1729–1753) used this method to determine the lems with their solutions on the ABC homepage at http://www. strength of vinegar by adding small amounts of potassium springer.com/abc. Test your knowledge and tease your wits in carbonate until the no further effervescence was observed diverse areas of analytical and bioanalytical chemistry by [2]. William Lewis (1708–1781), who is also considered one viewing this collection. of the early pioneers of titration, recognized the difficulty in In the present challenge, titration is the topic. And please determining the endpoint of the titration through the process note that there is a prize to be won (a Springer book of your of cessation of effervescence, so he suggested the use of color choice up to a value of €100).
    [Show full text]
  • Gas Chromatography-Mass Spectroscopy
    Gas Chromatography-Mass Spectroscopy Introduction Gas chromatography-mass spectroscopy (GC-MS) is one of the so-called hyphenated analytical techniques. As the name implies, it is actually two techniques that are combined to form a single method of analyzing mixtures of chemicals. Gas chromatography separates the components of a mixture and mass spectroscopy characterizes each of the components individually. By combining the two techniques, an analytical chemist can both qualitatively and quantitatively evaluate a solution containing a number of chemicals. Gas Chromatography In general, chromatography is used to separate mixtures of chemicals into individual components. Once isolated, the components can be evaluated individually. In all chromatography, separation occurs when the sample mixture is introduced (injected) into a mobile phase. In liquid chromatography (LC), the mobile phase is a solvent. In gas chromatography (GC), the mobile phase is an inert gas such as helium. The mobile phase carries the sample mixture through what is referred to as a stationary phase. The stationary phase is usually a chemical that can selectively attract components in a sample mixture. The stationary phase is usually contained in a tube of some sort called a column. Columns can be glass or stainless steel of various dimensions. The mixture of compounds in the mobile phase interacts with the stationary phase. Each compound in the mixture interacts at a different rate. Those that interact the fastest will exit (elute from) the column first. Those that interact slowest will exit the column last. By changing characteristics of the mobile phase and the stationary phase, different mixtures of chemicals can be separated.
    [Show full text]
  • 22 Chromatography and Mass Spectrometer
    MODULE Chromatography and Mass Spectrometer Biochemistry 22 Notes CHROMATOGRAPHY AND MASS SPECTROMETER 22.1 INTRODUCTION We know that the biochemistry or biological chemistry deals with the study of molecules present in organisms. These molecules are called as biomolecules and they form the basic unit of every cell. These include carbohydrates, proteins, lipids and nucleic acids. To study the biomolecules and to know their function, they have to be obtained in purified form. Purification of the biomolecules includes many physical and chemical methods. This topic gives about two of the commonly used methods namely, chromatography and mass spectrometry. These methods deals with purification and separation of biomolecules namely, protein and nucleic acids. OBJECTIVES After reading this lesson, you will be able to: z define the chromatography and mass spectrometry z describe the principle and important types of chromatographic methods z describe the principle and components of a mass spectrometer z enlist types of mass spectrometer z describe various uses of mass spectrometry 22.2 CHROMATOGRAPHY When we have a mixture of colored small beads, it is easily separated by visual examination. The same holds true for many chemical molecules. In 1903, 280 BIOCHEMISTRY Chromatography and Mass Spectrometer MODULE Mikhail, a botanist (person studies plants) described the separation of leaf Biochemistry pigments (different colors) in solution by using solid adsorbents. He named this method of separation called chromatography. It comes from two Greek words: chroma – colour graphein – to write/detect Modern separation methods are based on different types of chromatographic methods. The basic principle of any chromatography is due to presence of two Notes phases: z Mobile phase – substances to be separated are mixed with this fluid; it may be gas or liquid; it continues moves through the chromatographic instrument z Stationary phase – it does not move; it is packed inside a column; it is a porous matrix that helps in separation of substances present in sample.
    [Show full text]
  • 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 ......................................................................
    [Show full text]
  • Comparison of Vitamin C Content in Citrus Fruits by Titration and High Performance Liquid Chromatography (HPLC) Methods
    International Food Research Journal 24(2): 726-733 (April 2017) Journal homepage: http://www.ifrj.upm.edu.my Comparison of vitamin C content in citrus fruits by titration and high performance liquid chromatography (HPLC) methods 1Fatin Najwa, R. and 1,2*Azrina, A. 1Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, 43400 UPM Serdang, Selangor, Malaysia 2Research Centre of Excellence, Nutrition and Non-communicable Diseases, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia Article history Abstract Received: 29 June 2015 Vitamin C is one of the essential vitamins for human and animal. Many methods were Received in revised form: developed for the determination of vitamin C such as spectrophotometry, electrophoresis, 23 March 2016 titration, and high performance liquid chromatography (HPLC). This study aims to compare Accepted: 4 April 2016 vitamin C content of citrus fruits (orange, grapefruit, lemon, lime, kaffir lime and musk lime) using indophenol titration and HPLC-PDA methods. In the titration method, orange has the highest vitamin C content (58.30 mg/100g) followed by grapefruit (49.15 mg/100g), lemon Keywords (43.96 mg/100g), kaffir lime (37.24 mg/100g), lime (27.78 mg/100g) and musk lime (18.62 Vitamin C mg/100g). While, in the HPLC method orange also leads with the highest vitamin C content Ascorbic acid (43.61 mg/100g) followed by lemon (31.33 mg/100g), grapefruit (26.40 mg/100g), lime (22.36 Citrus fruits mg/100g), kaffir lime (21.58 mg/100g) and musk lime (16.78 mg/100g).
    [Show full text]
  • Determination and Identification of Fundamental Amino Acids by Thermometric Titration and Nuclear Magnetic Resonance Spectroscopy
    Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1967 Determination and Identification of Fundamental Amino Acids by Thermometric Titration and Nuclear Magnetic Resonance Spectroscopy. William Yong-chien Wu Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Wu, William Yong-chien, "Determination and Identification of Fundamental Amino Acids by Thermometric Titration and Nuclear Magnetic Resonance Spectroscopy." (1967). LSU Historical Dissertations and Theses. 1274. https://digitalcommons.lsu.edu/gradschool_disstheses/1274 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. This dissertation has been microfilmed exactly as received 67-8805 WU, William Yong-Chien, 1939- DETERMINATION AND IDENTIFICATION OF FUNDAMENTAL AMINO ACIDS BY THERMOMETRIC TITRATION AND NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY. Louisiana State University and Agricultural and Mechanical College, Ph.D., 1967 Chemistry, analytical University Microfilms, Inc., Ann Arbor, Michigan Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. DETERMINATION AND IDENTIFICATION OF FUNDAMENTAL AMINO ACIDS BY THERMOMETRIC TITRATION AND NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Chemistry by William Yong-Chien Wu B.A., Hardin Simmons University, I96I January, I967 Reproduced with permission of the copyright owner.
    [Show full text]
  • Coupling Gas Chromatography to Mass Spectrometry
    Coupling Gas Chromatography to Mass Spectrometry Introduction The suite of gas chromatographic detectors includes (roughly in order from most common to the least): the flame ionization detector (FID), thermal conductivity detector (TCD or hot wire detector), electron capture detector (ECD), photoionization detector (PID), flame photometric detector (FPD), thermionic detector, and a few more unusual or VERY expensive choices like the atomic emission detector (AED) and the ozone- or fluorine-induce chemiluminescence detectors. All of these except the AED produce an electrical signal that varies with the amount of analyte exiting the chromatographic column. The AED does that AND yields the emission spectrum of selected elements in the analytes as well. Another GC detector that is also very expensive but very powerful is a scaled down version of the mass spectrometer. When coupled to a GC the detection system itself is often referred to as the mass selective detector or more simply the mass detector. This powerful analytical technique belongs to the class of hyphenated analytical instrumentation (since each part had a different beginning and can exist independently) and is called gas chromatograhy/mass spectrometry (GC/MS). Placed at the end of a capillary column in a manner similar to the other GC detectors, the mass detector is more complicated than, for instance, the FID because of the mass spectrometer's complex requirements for the process of creation, separation, and detection of gas phase ions. A capillary column is required in the chromatograph because the entire MS process must be carried out at very low pressures (~10-5 torr) and in order to meet this requirement a vacuum is maintained via constant pumping using a vacuum pump.
    [Show full text]
  • Determination of the Chemical Concentrations
    American Journal of Analytical Chemistry, 2014, 5, 205-210 Published Online February 2014 (http://www.scirp.org/journal/ajac) http://dx.doi.org/10.4236/ajac.2014.53025 Online Process Control of Alkaline Texturing Baths: Determination of the Chemical Concentrations Martin Zimmer, Katrin Krieg, Jochen Rentsch Department PV Production Technology and Quality Assurance, Fraunhofer Institute for Solar Energy Systems, Freiburg, Germany Email: [email protected] Received December 16, 2013; revised January 20, 2014; accepted January 28, 2014 Copyright © 2014 Martin Zimmer et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In accor- dance of the Creative Commons Attribution License all Copyrights © 2014 are reserved for SCIRP and the owner of the intellectual property Martin Zimmer et al. All Copyright © 2014 are guarded by law and by SCIRP as a guardian. ABSTRACT Almost every monocrystalline silicon solar cell design includes a wet chemical process step for the alkaline tex- turing of the wafer surface in order to reduce the reflection of the front side. The alkaline texturing solution contains hydroxide, an organic additive usually 2-propanol and as a reaction product silicate. The hydroxide is consumed due to the reaction whereas 2-propanol evaporates during the process. Therefore, the correct reple- nishment for both components is required in order to achieve constant processing conditions. This may be sim- plified by using analytical methods for controlling the main components of the alkaline bath. This study gives an overview for a successful analytical method of the main components of an alkaline texturing bath by titration, HPLC, surface tension and NIR spectrometry.
    [Show full text]
  • The Birth of Titrimetry: William Lewis and the Analysis of American Potashes
    66 Bull. Hist. Chem., VOLUME 26, Number 1 (2001) THE BIRTH OF TITRIMETRY: WILLIAM LEWIS AND THE ANALYSIS OF AMERICAN POTASHES Frederick G. Page, University of Leicester. William Lewis (1708- In order to place 1781), was a physician, author, Lewis’s work in the context and an experimental chemist. of the early beginnings of Sometime after 1730 he gave the industrial revolution in public lectures in London on Britain, Sivin (4) has used a chemistry and the improve- chronological argument; he ment of pharmacy and manu- cites Ashton’s suggestion facturing arts (1). With a grow- (5) that 1782 was the begin- ing reputation as a chemical ning of the industrial revo- experimentalist he was elected lution because in that year F.R.S., on October 31,1745, most statistics indicated a and was then living in Dover sharp increase in industrial Street, London. In 1747 he production. But, as Sivin moved to Kingston-upon- argues, it seems reasonable Thames, where he set up a to assume that by the time well-equipped laboratory and such early statistics became presumably continued in medi- available, those industries cal practice. From about 1750 that had created salable until his death in 1781 Lewis products had already be- employed Alexander Chisholm come established and were as his assistant in chemical and no longer in their early literary works (2). These im- years of founding. On this proved the knowledge and basis the industrial revolu- practice of pharmacy, but as a tion must have begun ear- practical consulting chemist lier. By the middle of the Lewis has received little bio- eighteenth century the so- graphical recognition.
    [Show full text]
  • High Performance Liquid Chromatographic Assay of Chlorpropamide, Stability Study and Its Application to Pharmaceuticals and Urine Analysis
    Open Access Austin Journal of Analytical and Pharmaceutical Chemistry Research Article High Performance Liquid Chromatographic Assay of Chlorpropamide, Stability Study and its Application to Pharmaceuticals and Urine Analysis Basavaiah K1* and Rajendraprasad N2 1Department of Chemistry, University of Mysore, Mysuru, Abstract Karnataka, India Chlorproamide (CLP) is a sulphonyl-urea derivative used in the treatment 2PG Department of Chemistry, JSS College of Arts, of type 2 diabetes mellitus. A rapid, sensitive and specific HPLC method with Commerce & Science, B N Road, Mysuru, Karnataka, uv detection is described for the determination of CLP in bulk and tablet forms. India The assay was performed on an Inertsil ODS 3V (150mm × 4.6mm; 5µm *Corresponding author: Basavaiah K, Department particle size) column using a mixture of phosphate buffer (pH 4.5), methanol of Chemistry, University of Mysore, Manasagangothri, and acetonitrile (30:63:7v/v/v) as mobile phase at a flow rate of 1mLmin-1 and Mysuru, Karnataka, India with uv detection at 254nm. The column temperature was 30ᴼC and injection volume was 20µL. The retention behaviour of CLP as a function of mobile phase Received: February 27, 2017; Accepted: March 16, pH, composition and flow rate was carefully studied, and chromatographic 2017; Published: March 22, 2017 conditions, yielding a symmetric peak with highest number of theoretical plates, were optimized. The calibration curve was linear (r = 0.9999) over the concentration range 0.5 – 300 µgmL-1. The limits of detection (LOD) and quantification (LOQ) were found to be 0.1 and 0.3 µgmL-1, respectively. Both intra-day and inter-day precisions determined at three concentration levels were below 1.0% and the respective accuracies expressed as %RE were ≤1.10%.
    [Show full text]