Identification colorimetric

Analytical and Test Methods. Colorimetric quaUtative tests for diketene are known but seldom used (131). Identification is by spectrometric methods. Diketene has typical ir absorption bands at - ISSO, 1855, and 1685 cm , and signals at 3.92 (t), 4.51 (m), and 4.87 (m) ppm in the H-nmr spectmm (CDCl ). Purity is routinely monitored by gc. Alternatively, diketene is quantitatively converted to acetoacetic derivatives which are assayed by standard methods. 

Identifications in terms of gas chromatographic responses, infrared data, and colorimetric tests... 

Phenolic antioxidants in rubber extracts were determined indirectly photometrically after reaction with Fe(III) salts which form a red Fe(II)-dipyridyl compound. The method was applicable to Vulkanox BKF and Vulkanox KB [52]. Similarly, aromatic amines (Vulkanox PBN, 4020, DDA, 4010 NA) were determined photometrically after coupling with Echtrotsalz GG (4-nitrobenzdiazonium fluoroborate). For qualitative analysis of vulcanisation accelerators in extracts of rubbers and elastomers colour reactions with dithio-carbamates (for Vulkacit P, ZP, L, LDA, LDB, WL), thiuram derivatives (for Vulkacit I), zinc 2-mercaptobenzthiazol (for Vulkacit ZM, DM, F, AZ, CZ, MOZ, DZ) and hexamethylene tetramine (for Vulkacit H30), were mentioned as well as PC and TLC analyses (according to DIN 53622) followed by IR identification [52]. 8-Hydroquinoline extraction of interference ions and alizarin-La3+ complexation were utilised for the spectrophotometric determination of fluorine in silica used as an antistatic agent in PE [74], Also Polygard (trisnonylphenylphosphite) in styrene-butadienes has been determined by colorimetric methods [75,76], Most procedures are fairly dated for more detailed descriptions see references [25,42,44],... 

Polyatomic Organic Molecules. Metal Complexes. Qualitative Analysis - The Identification of Structural Features. Quantitative Analysis - Absorptiometry. Choice of Colorimetric and Spectrophotometric Procedures. Fluorimetry. Applications of UV/Visible Spectrometry and Fluorimetry. 

Part—I has three chapters that exclusively deal with General Aspects of pharmaceutical analysis. Chapter 1 focuses on the pharmaceutical chemicals and their respective purity and management. Critical information with regard to description of the finished product, sampling procedures, bioavailability, identification tests, physical constants and miscellaneous characteristics, such as ash values, loss on drying, clarity and color of solution, specific tests, limit tests of metallic and non-metallic impurities, limits of moisture content, volatile and non-volatile matter and lastly residue on ignition have also been dealt with. Each section provides adequate procedural details supported by ample typical examples from the Official Compendia. Chapter 2 embraces the theory and technique of quantitative analysis with specific emphasis on volumetric analysis, volumetric apparatus, their specifications, standardization and utility. It also includes biomedical analytical chemistry, colorimetric assays, theory and assay of biochemicals, such as urea, bilirubin, cholesterol and enzymatic assays, such as alkaline phosphatase, lactate dehydrogenase, salient features of radioimmunoassay and automated methods of chemical analysis. Chapter 3 provides special emphasis on errors in pharmaceutical analysis and their statistical validation. The first aspect is related to errors in pharmaceutical analysis and embodies classification of errors, accuracy, precision and makes... 

A variety of methods were developed for the identification and determination of the antimicrobial nitrofurans. They include LC, colorimetric and polarographic methods. Nitrofurans could be determined in animal tissues by extraction with acetonitrile, SPE and LC-UVD533. An LC-UVD method was statistically validated for the determination of nitrofuran drug residues in poultry534. 

In view of its rapidity we found thin layer chromatography convenient for identification of the amino acids liberated by the first 20—30 degradation cycles. For identification of PTH-derivatives from additional degradation steps we prefer gas-liquid chromatography because of its merits mentioned above, particularly its greater sensitivity. Several colorimetric reactions and chromatographic systems are available for the identification of those PTH-amino acids which remain in the aqueous phase when the PTH-derivatives are extracted with ethyl acetate 23.24,25,13) our hands, thin layer electrophoresis was found to be satisfactory 26,27)... 

Store it in a CaCl2 desiccator Separation and identification of Low Freezing Compounds and Nitrocompounds of Explosive Oils are briefly described here under Pierson s Procedure D-3 (See above). The tests are colorimetric. Some of these compds may be identified by IR and X-ray spectroscopy (Ref 11, pl363)... 

Transfer the soln to a vol flask, take an aliquot and test it colorimetrically Note If additional identification is desired, det nitrogen content by titanous chloride... 

Ethanol and a long list of carbonyl compounds and aliphatic acids occur in fresh milk (Table 1.5). Some of them have been detected in only a few of the samples in which they were sought. Techniques for detecting such compounds include derivatization with 2,4-dinitrophe-nylhydrazine and various methods of volatilization, extraction, and chromatography (Harper and Huber 1956 Morr et al. 1957 Harper et al. 1961 Wong and Patton 1962 Scanlan et al. 1968 Marsili et al. 1981). The sum of the concentrations of acids listed in Table 1.5 is only 1-3 mmol/liter, compared to the citrate concentration of 10 mmol/liter. Oxalate has been reported to occur in milk (Zarembski and Hodgkin-son 1962) on the basis of a certain colorimetric reaction, but positive identification has not been made. 

One of the more important areas of use of ultraviolet instruments is the identification and determination of biologically active substances. Many components in body fluids can be determined either directly or through colorimetric methods. Drugs and narcotics can be measured both in the body as well as in formulations. Vitamin assay is another related activity. Nearly all metals and nonmetals can be determined through their ultraviolet absorption or by colorimetric methods. In recent years, ultraviolet instruments have been used extensively for the determination of air and water pollutants, such as aldehydes, phenolics, and ozone ... 

The instrument used in colorimetry is called colorin eter it determines and specifies colors by referring to other colors. This process will permit,by the proper selection of suitable reagents, the identification of principle ingredients in the sample tested when it is in solution. The depth of color, measured by the colorimeter, gives the quantity of material present in a solution. This is known as colorimetric analysis (See also Color... 

A more detailed description of tests for LA is given in Vol l,pp A580-R to A587-R of Encycl Tests for Propellants Since std colloidal proplnts are mixts of colloided NC with explosive(such as NG, NGu, DEGDN, etc ) and nonexpl ingredients(such as DPhA, EtCentr, DBuPh, etc), no simple colorimetric tests are known for identification of components without preliminary separation of them. The separation can be done by solvent extractions, fractionation of the extracts or by chromatographic separation... 

PETN or materials used for their manuf, such as DPhA or dim ethyl amine) p 3(Improved Webster s test) pp 3-4(SneIling s colorimetric test for TNT on the skin) p 4(Neal s test for TNT on the skin) p 5(Pinto St Fahy s colorimetric test for TNT in the air) 10)G. Halfter 8c H. Winkler, Die Chemie 57, 124-25(1944)(Colori-metri c detn of TNT) lOa)I.Eisdorfer, PicArsn ChemLabRept 107708(l944)(Identification of HE s) ll)M. Schechter 8c H.L. Haller, IEC, AnalEd 16, 325-26(1944)(Colorimetric detn of... 

Pyrotechnic Items, PATR 2164(1955) 22a) Anon, Military Explosives , Dept of the Army TM 9 1910(1955), 267-73(Identification of expls proplnts) 23)M. Ledercq, MP 37, 507-11 (1955) [Colorimetric detn of Dinitrochlorobenzene in Dinitromethylaniline(an intermediary in prepn of Tetryl) by means of pyridine. With this substance DNCB gives a red coloration, while DNMeA produces a yel color] 24)P. Tavernier M. Lamouroux, MP 38, 65-88(1956) [Colorimetric detns of 26org compds which are considered to be suitable as components of proplnts w ere made by, using Muraour s Reagent (qv)] 25) "The BDH Book of Organic... 

Composition A Type Explosives, Analytical Procedures. Composition A-3.Colorimetric method of identification is described in this volume of Encyclopedia under Color Reactions and Color Reagents and also in Refs 2 7... 

---