Spectrophotometric analyses

Alkaline hydrolyzate of tetra-O-acetyl-(2-hydroxy-D-orofefno-hexose) 315 249 63 

Neutral solutions of pure aldoses exhibit no selective absorption in the ultraviolet region103 106 such an absorption may, however, be observed108 for solutions of D-glucose and L-arabinose in 50% sulfuric acid, and is 

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Simultaneous Cr O " and MnOj" detemiination (Ewing, 1985) is a multivariate spectrophotometric analysis that requires detemiination of a matrix of four calibration constants, one for each unknown at each of two wavelengths. 

Description of Method. The FIA determination of phosphate is an adaptation of a standard spectrophotometric analysis for phosphate. In the presence of add, phosphate reacts with molybdate to form a yellow-colored complex in which molybdenum is present as Mo(VI). 

The most commonly used method for first-order rate constant evaluation in the absence of a final reading is Guggenheim s method. We continue to use spectrophotometric analysis as an example. From Eq. (2-52) we write, for time t. 

An alternative elution technique is to transfer the powder (e.g. for bromophenol blue) to a glass column fitted with a glass-wool plug or glass sinter, and elute the dye with ethanol containing a little ammonia. The eluted solution, made up to a fixed volume in a small graduated flask, may be used for colorimetric/ spectrophotometric analysis of the recovered dye (see Chapter 17). A calibration curve must, of course, be constructed for each of the individual compounds. 

In spectrophotometric analysis a source of radiation is used that extends into the ultraviolet region of the spectrum. From this, definite wavelengths of radiation are chosen possessing a bandwidth of less than 1 nm. This process necessitates the use of a more complicated and consequently more expensive instrument. The instrument employed for this purpose is a spectrophotometer. 

Mass Spectrophotometric Analysis of Complex Gas Mixtures , ERDE-TN-28 (Engl), TRC, BR-2S066 (1971) 31) W.F. Pickering,... 

Based on gas-liquid chromatographic (GLC) or GLC-mass spectrophotometric analysis. 

An area worthy of study is the development of systems of increasing sample throughput beyond the single column operation. Scott has introduced a prototype multicolumn system based on the centrifugal analyzer principle (53). In this set-up a series of LC colimns is rotated on a disc, with sample delivery at the center of the disc and elution and spectrophotometric analysis on the outside. He has suggested using affinity columns for rapid serum protein analysis by this approach. Of course, other principles, such as segmented flow, could be envisioned in an automated LC system as well. Undoubtedly, we can expect to see the availability of such systems in the next few years. 

A stopped flow technique coupled with spectrophotometric analysis of the iron (II) complex formed has been used to investigate - the reactions of some organic complexes of iron(III) with the ion Fe ". The iron(III) was complexed with 1,10-phenanthroline, various substituted 1,10-phenanthrolines (5-methyl-, 5-nitro-, 5-chloro-, 5-phenyl-, 5,6-dimethyl-, 4,7-diphenyl-, and 3,4,7,8-tetramethyl-) and 2,2 -dipyridine, 4,4 -dimethyl-2,2 -dipyridine, and 2,2, 2"-tripyridine. The wavelengths used for the analysis lay in the region 500-552 m/i. 

The simultaneous analysis of orthophosphate, glycerol phosphates, and inositol phosphates has been achieved by spectrophotometric analysis of the molybdovanadate complexes. Also, a sensitive and selective chemiluminescent molecular emission method for the estimation of phosphorus and sulphur is described, which is based on passing solutions into a cool, reducing, nitrogen-hydrogen diffusion flame. For organic compounds it was usually necessary to prepare test solutions by an oxygen-flask combustion technique. 

One technique to assess lipid peroxidation utilizes second-derivative spectrophotometric analysis of cyclohexane or ethanol-reconstituted extracts to determine the cis-trans and trans-trans isomeric forms of conjugated dienes and oxodiene species within synovial fluid. Using this method, a rise in the synovial fluid concentration of conjugated oxodienes, hydroxydienes and hydroperoxy-dienes was found to follow joint exercise (Merry et al., 1991). 

While the control resins were deep red in color due to the presence of soluble porphyrin complexes, the methacrylate resins obtained after removal of the polyethylene-supported catalysts varied from light yellow to nearly water-white (APHA < 25). UV-Vis spectrophotometric analysis of the yellow resins indicated an absorption signal for the cobalt porphyrin complex Soret band (wavelength of cobalt(ll) porphyrin species appears at -415 nm free porphyrin ligand is formd at -423 tun). Resin samples that visttally appear as water-white show little or no porphyrin species present in the spectrum. Measured catalyst activity and PDl of the polyethylene-supported porphyrin complexes are in the expected range for soluble porphyrin CCT catalysts (PDl = M /Mn - 1.2- 2.0)." The screening resrrlts clearly... 

Bailey, D.N., Evaluation of drug interferences in the ultraviolet spectrophotometric analysis of plasma theophylline, J. Anal. Toxicol., 2,94,1978. 

B. M. H. Al-Hadiya, Spectrometric and Spectrophotometric Analysis of Some Anthelmintics, Master of Science thesis, the School of Pharmacy and Pharmacology, University of Bath, UK, 1981. 

Raggi et al. [21] described a spectrophotometric analysis method with ammonium tetrachloropalladate for penicillamine in pharmaceutical formulations. An aqueous solution of penicillamine (298 pg/mL) was treated with 1.5 mL of 20 mM (NH4)2PdCl4 in 1 M HC1. The mixture was diluted to 10 mL, and the absorbance measured at 403 nm after 20 min. The method has a recovery of 98.8%, and was used to determine penicillamine in aqueous extracts of capsules. 

Spectrophotometric analysis and complexometric titrations have long been used to determine calcium, with much effort devoted to developing reagents and indicators that permit the... 

Zhao X, Flardin IR (2007) HPLC and spectrophotometric analysis of biodegradation of azo dyes by Pleurotus ostreatus. Dyes Pigm 73 322-325... 

Spectrophotometric analysis following extraction with Aliquot 336 has been used to determine uranium in seawater [108]. Kim and Burnett [109] used X-ray spectrometry to determine the uranium series nucleides including 238uranium, 226radium and 210lead in marine phosphorites. 

The ionization of certain substances, notably triarylmethyl cyanides, is promoted by light, so that spectrophotometric analysis for carbonium ions is no exception to the rule that the analyst should be alert for any parallelism between the duration of exposure to light during the analysis and the result.1 7 -1 9... 

More recently, a colorimetric-based LAL procedure has been devised. This entails addition to the LAL reagent of a short peptide, susceptible to hydrolysis by the LAL clotting enzyme. This synthetic peptide contains a chromogenic tag (usually para-nitroaniline, pNA) which is released free into solution by the clotting enzyme. This allows spectrophotometric analysis of the test sample, facilitating more accurate end-point determination. 

An ultraviolet spectrophotometric analysis is used to assay pseudoephedrine hydrochloride in tablets. A portion of finely powdered tablets equivalent to approximately 30 mg of pseudoephedrine hydrochloride is placed in a distilling flask which is part of a micro-steam distillation apparatus. Sodium chloride, water, and concentrated sodium hydroxide are added. A minimum of 30 ml of distillate is collected in a volumetric flask containing dilute hydrochloric acid. The flask is made to volume with distilled water and the absorbance of the solution is determined at 257 nm in 1 cm cells and compared to a solution of known concentration of NF Pseudoephedrine Hydrochloride Reference Standard.1... 

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