Periodate oxidation spectrophotometric determination

An ultraviolet spectrophotometric method based on the absorbance of a periodate oxidation product of pseudoephedrine hydrochloride will be the official method of analysis in the USP XX.19,20 A portion of tablets or syrup in water is placed in a separatory funnel. Sodium bicarbonate and sodium metaperiodate are added. After standing for 15 minutes, 1 N HC1 is added. The solution is extracted with hexane. The hexane extract is filtered and its absorbance determined at 242 nm in 1 cm cells. The amount of the oxidation product of pseudoephedrine hydrochloride is determined by comparison of the sample absorbance against the absorbance of a Pseudoephedrine Hydrochloride Reference Standard treated in the same manner. 

The oxidation may be performed at pH 5.0 by addition of an aqueous solution of sodium metaperiodate. The reaction is allowed to proceed in the dark at 4 °C and after 24 hours the excess periodate is destroyed by the addition of ethylene glycol. The aims in periodate oxidation are to elucidate the number of neighbouring hydroxyl groups by estimating the number of moles of periodate consumed and to determine the structure of the moiety remaining after the reaction. The amount of periodate used in the reaction may be determined in several ways, including titrimetric and spectrophotometric methods. 

These difficulties may be overcome by the method of Johnson and Sieburth (1977), who combined several well-known reactions of carbohydrates to gain specificity in the determination. Their spectrophotometric assay included reduction of free monosaccharides to sugar alcohols with KBH4, periodate oxidation and subsequent determination of the liberated formaldehyde with 3-methyl-2-benzothia olinone hydrazone hydrochloride. Since only one compound is actually determined (formaldehyde), the problems associated with varying responses of different sugars are eliminated. 

The consumption of oxidant is most generally determined by volumetric methods—periodate by titration with arsenite, and both oxidants by iodime-try. Spectrophotometric methods are also frequently used for determining periodate and lead tetraacetate, and are especially useful for microoxidations or highly dilute reaction mixtures. Spectrophotometric determination of the extent of conversion of the violet dye tris[2,4,6-tris(2-pyridyl)-l,3,5-triazino]iron(II) into its colorless ferric state reportedly provides a means of quantitating nanomole amounts of unreacted periodate, and it has been coupled... 

G. O. Aspinall and R. J. Ferrier, Spectrophotometric method for the determination of periodate consumed during the oxidation of carbohydrates, Chem. Ind. (London), (1956) 1216 J. X. Khym, Direct spectrophotometric determination of iodate following periodate oxidation of a-glycol groups, Methods Carbohydr. Chem., 6 (1972) 87-93. 

Another modification of the catalytic kinetic spectrophotometric method has been established for the determination of iodine using the principle that potassium periodate oxidize rhodamine B (RhB) to discolor and 1 has a catalytic effect on the reaction. The absorbance difference (AA) is linearly related with the concentration of iodine in the range of 0 - 2.6 pg/mL and fits the equation AA = 0.1578 C(C pg/mL) + 0.0052, with a regression coefficient of 0.9965. The detection limit of the method is 7.10 ng/mL. The method was used to determine iodine in kelp, potato, tap water, and rain water samples. The relative standard deviation of 13 replicate determinations was 1.81-2.10%. The recovery of the standard addition of the method was 96.2-99.2% (Zhaiet al., 2010). 

Spectrophotometric detection Polyols can be determined by estimating the formaldehyde produced after mild periodate oxidation using arsenic(III) oxide... 

The methylated catecholamines have most commonly been estimated by spectrophotometric determination of the vanillin formed from their oxidation by periodate [8], after extraction from the urine by ion-exchange chromatography. A method using HPLC and ECD has now been... 

Periodate ion has been determined by the formation of a chromophore with 2,2 -azinobis(3-ethylbenzothiazoline-6-sulphonic acid) and by means of an iodide-selective electrode. " The 2,4-dinitrophenylhydrazones derived from aldehydic fragments produced on periodate oxidation of carbohydrates have been separated by t.l.c., after which the individual hydrazones could be determined spectrophotometrically. ... 

Periodate oxidation is relatively easy to perform, and the amount of periodate consumed is easy to determine spectrophotometrically by measuring the absorbance at 290 nm, using an absorbance coefficient of 0.22 mM/cm [17]. Sometimes formic acid is a product of the reaction, and it too is relatively easy to measure by acid/base titration. Different kinds of linkages in a polysaccharide or in an oligosaccharide consume different amounts of periodate and form different amounts of formic acid. From this, deductions can be made about the kinds of gly-cosidic linkage(s) present. 

Khym, J. X. Direct Spectrophotometric Determination of lodate Following Periodate Oxidation of a-Glycol Groups Quantitative Removal of lodate and Periodate by Ion-Exchange Materials or by Solvent Extraction. Methods Carbohyd. Chem. 6, 87 (1973). 30 5931... 

Kinetic mles of oxidation of MDASA and TPASA by periodate ions in the weak-acidic medium at the presence of mthenium (VI), iridium (IV), rhodium (III) and their mixtures are investigated by spectrophotometric method. The influence of high temperature treatment with mineral acids of catalysts, concentration of reactants, interfering ions, temperature and ionic strength of solutions on the rate of reactions was investigated. Optimal conditions of indicator reactions, rate constants and energy of activation for arylamine oxidation reactions at the presence of individual catalysts are determined. 

A kinetic method for the determination of 2,4-dinitrophenol is proposed. The method is based on the inhibiting effect of 2,4-dinib ophenol on the Mn(II) catalysis of the oxidation of malachite green with potassium periodate. The reaction was followed spectrophotometrically at 615 nm. The optimal experimental conditions for the determination of 2,4-dinitrophenol were established under the optimal reaction conditions ... 

This element has been determined in perchloric acid digests of plant materials by a spectrophotometric procedure as permanganate ion obtained by oxidation with periodic acid or by AAS using the 279.5 nm emission line [28]. 

A colorimetric method based on the inhibitory effect of EDTA on the Mn(II) catalyzed oxidation of malachite green by periodate was reported [32]. An alternative method based on using Fe(III) instead of Mn(II) was proposed [33]. The reduction of the absorbance of Bi(III) bromo-pyrogallol red tenside ternary complex upon the addition of EDTA has been exploited for its determination. Calibration curves obtained at 650 nm were linear over the range of 0.2-6 pg/mL of EDTA [34]. EDTA in ophthalmic solutions could be assayed by spectrophotometric titration using Mg(II) as the titrant and Arsenazo I as the indicator. The working range was 0.05-2 pg/mL [35]. 

There are very sensitive catalytic spectrophotometric methods for the determination of manganese, in which traces of Mn(II) catalyse the oxidation of various organic substances by another oxidant (e.g., KIO4), with the formation of coloured reaction products. In these methods, the amount of colour depends on the reaction time. The catalytic effect of Mn on oxidation of Malachite Green by periodate has been utilised in determination of manganese by the FI A method [54—57]. 

A number of spectrophotometric methods for determining Rh has been based on its catalytic effect on redox reactions, such as the oxidation of Methyl Red [66], Methyl Orange [67], or copper [68] with periodate. The catalytic reactions have been the basis for Rh determinations in technological samples [67] and in copper and nickel alloys [68]. 

The airborne aerosol is filtered and after the filter mineralization, manganese is determined in the solution by a spectrophotometric method following oxidation with periodate in acid medium to the red-violet MnO anion... 

Formic acid is produced from a 1,2,3-triol grouping. As this acid is stable toward periodate, it is readily determined by volumetric or potentiometric titration of the reaction mixture, by highly sensitive spectrophotometric methods, or manometrically. Lead tetraacetate slowly oxidizes formic acid to carbon dioxide, which may complicate the stoichiometry of the glycol-cleavage... 

Arabinitol, xylitol, and ribitol have been determined by oxidation with periodate, the excess of oxidant being measured by potentiometric titration with hydrazine sulphate. Periodate ions have also been determined by spectrophotometric measurement of the absorbance at 555 nm following the addition of phenolphthalein at pH 11.6. ... 

A. A. Ensafi and M. Keyvanfard, Kinetic spectrophotometric method for the determination of rhodium by its catalytic effect on the oxidation of o-toluidine blue by periodate in micellar media, Journal of Analytical Chemistry, vol. 58, no. 11, pp. 1060-1064, 2003. 

Other procedures are based upon determination of the decomposition products of poly-oxyalkalene compounds. By reaction with phosphoric acid, ethylene oxide and propylene oxide moieties are converted, with 80-90% yield, to acetaldehyde and propionaldehyde, which may be measured spectrophotometrically (106). By more drastic decomposition with perchloric acid and periodate ion, the oxyalkalene compounds are converted to formaldehyde, with 55-65% yield, which may be distilled and determined colorimetrically (107). Neither of these methods has been much used. 

---