Extraction analytical reagents

Crown ethers as analytical reagents and extractants of radionuclides 98MI36. 

This section provides a brief review of a number of chelating and other extraction reagents, as well as some organic solvents, with special interest as to their selective extraction properties. The handbook of Cheng et al. should be consulted for a more detailed account of organic analytical reagents.11... 

Unlike the previously mentioned systems, compounds such as (191) and (192) show no tendency to yield 2 1 (L M) complexes. These compounds show much promise as analytical reagents for the alkali metals and, for instance, have been demonstrated to be suitable for the extraction and spectrophotometric determination of Na+ in human blood serum. 

Materials. Aldicarb standards were obtained from the United States Environmental Protection Agency (USEPA), Quality Assurance Section and from Union Carbide Corporation. Crystalline samples of carbofuran and 3-hydroxycarbofuran were supplied by the Agricultural Chemical Group of FMC Corporation. Reference standards of methomyl (99% pure) and oxamyl (99% pure) were obtained from USEPA. HPLC grade methanol was purchased from Burdick and Jackson, Inc. Methylene chloride used for bulk extractions of the carbamate pesticides in solution was recovered, distilled and reused. Analytical reagent grade chemicals and solvents were used in all experiments. Doubly distilled deionized water was used for solution rate studies. Deionized distilled water (DDW) was used for dilutions in reactive ion exchange experim ts., , ... 

Sodium thiosulfate is a common analytical reagent used in iodometric titration to analyze chlorine, bromine, and sulfide. Other uses are in bleaching paper pulp, bleaching straw, ivory, and bones, for removing chlorine from solutions, silver extraction from its ores, a mordant in dyeing and printing textiles, and as an antidote to cyanide poisoning. 

Hydroxyquinoline (oxine, 6), one of the earliest analytical reagents, also is one of the most widely studied N—O bidentates. Its early coordination chemistry was reviewed by Phillips.19 Its use as an in vivo agent in microbiological systems has been reviewed by Schulman and Dwyer.20 The extensive use of oxine and substituted forms, and closely related bidentates, for the analytical solvent extraction and colorimeteric determination of metal ions has been comprehensively reviewed.21 An unusual bridged bonding mode for oxine has been reported in which N monodentate and O... 

Mercapto-l,5-diphenylformazan (dithizone, dzH) (42) was first prepared by Emil Fischer over a century ago.146 In 1925 Hellmut Fischer147 introduced dithizone as a versatile analytical reagent and subsequently explored its use for the solvent extraction and quantitative determination of a number of metals of industrial and toxicological interest. The conditions for the isolation and... 

Although composed of weak and overlapping spectral features, near-infrared spectra can be used to extract analytical information from complex sample matrices. Chemical sensing with in-line near-infrared spectroscopy is a general technique that can be used to quantify multiple analytes in complex matrices, often without reagents or sample pretreatment.7-9 Applications are widespread in the food sciences, agricultural industry, petroleum refining, and process analytical chemistry.10-13 These activities demonstrate that near-infrared spectroscopy can provide selective and accurate quantitative measurements both rapidly and nondestructively. 

Materials. Commercial cotton (Pakistani cotton) cut into 5 mm length and Whatman cellulose powder CF-11 was used as cellulose samples after Soxhlet extraction with alcohol-benzene for 7 h. Wood meal (mainly 40 - 80 mesh) from Makanba (Betula Maximowicziana Regel) was used after washing with cold water. Methyl methacrylate and styrene were purified by the conventional methods. Other reagents used were analytical reagent grade. 

When the extracted analytes provide no response on passing through a flow-cell located in a detector connected on-line to the continuous extractor via a dynamic manifold, the extractor outlet can also be connected to a manifold where the extract is merged with a stream of an appropriate reagent to derivatize the analytes as they are extracted, thereby enabling their subsequent on-line determination. This approach has been used to extract selenium from sand and sludge [57], and selenium, arsenic and mercury from coal. In the latter application, on-line derivatization with sodium tetrahydroborate (for selenium and arsenic) and tin chloride (for mercury) allowed the analytes to be determined in a direct manner using the atomic fluorescence technique [46]. 

The kerosene was purified by washing with concentrated sulphuric acid (4). The aqueous solutions of uranyl sulphate were prepared by dissolving uranyl sulphate hydrate (UO2SO4 3 0, Yokozawa Chemical Co. Ltd.) in sulphuric acid solutions of the required concentrations. All chemicals were of analytical reagent grade. Extraction and analytical procedures... 

Apart from PAR, many other azo reagents have been applied as spectrophotometric reagents for indium. l-(2-Pyridylazo)-2-naphthol (PAN) has been applied widely as analytical reagent for indium [24,36-38]. The indium chelate with PAN is extractable into chloroform from solutions of pH 6 (e = 1.9-10 ). Indium has also been determined with PAN by derivative spectrophotometry [39]. Other azo reagents proposed for indium include 2-(2-pyridylazo)-l-hydroxynaphthalene-4-sulphonic acid [40], TAR (formula 4.7) [41], Lumogallion (e = 5.4-10 at 510 nm) (formula 21.1) [42], Sulpharsazen [43], Thoron I [44], and Eriochrome Black T (extraction into n-butanol in the presence of diphenylguanidine, = 3.6-10 ) [45], Picramine M [46], 2-(2-thiazolylazo)-p-cresol (TAC) [47], and 2,4,6-tris(2-hydroxy-4-sulphonaphthylazo)l,3,5-triazine (e = 8.4-10 [48]. 

The use of pyrazol-3-ones as analytical reagents has been published in numerous articles and patents. For example, derivatives are useful for the extraction and separation of various metal ions (88JIC661), for the determination of phenol (87CJC2082), cyanides and ammonia (78ZN450), and as photographic sensitizers (71USP3615608). 

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