Spectrophotometric Determination of Ipratropium Bromide in Liquid for Nebulization

ABSTRACT

Three simple and sensitive spectrophotometric methods for the determination of ipratropium bromide (IPB) in liquid for nebulization are described. Method A, is based on the formation of a charge transfer complex with iodine. The reaction product is measured spectrophotometrically at 278 nm. Method B, is based oh the formation of an ion – association complex between the drug and an acidic dye, Bromocresol green (BCG), which is extractable into chloroform and has an absorption maximum at 418 nm. Method C, uses derivative spectrophotometry for the determination of IPB by measuring the D₂-value at 232 nm. Beer's law is obeyed over the concentration range 1-10, 2-16 and 5-30 μg ml^? for method A, B and C, respectively. The optimum conditions for the formation of the charge transfer or ion-association complexes were optimized. The proposed methods were applied for the determination of IPB in liquid for nebulization. Evaporation to dryness and extraction of the residue with isopropanol, were performed before application of methods A & B. Mean percentage recoveries were found to be 99.67 ± 0.79, 99.26 ± 1.06 and 100.21 ± 0.85 for method A, B, and C, respectively.     

Iodine-Catalyzed Addition of Methyl Thioglycolate to Chalcones

Abstract

A series of novel β-mercapto carbonyl compounds (3a–z), methyl 2-(3-oxo-1,3-diarylpropylthio)acetate, were synthesized and characterized via iodine-catalyzed addition of methyl thioglycolate to chalcones (1a–z).

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Determination of Iodine in Cereal Grains and Standard Reference Materials by Neutron Activation Anaylsis

Abstract

Trace amounts of iodine in thirty-eight cereal grain samples cultivated at different locations in Austria were determined for the first time in this study by radiochemical neutron activation analysis. For the dissolution of cereal grain samples and standard reference materials, two different procedures, alkaline and acidic dissolution, were applied in the presence of an iodine carrier. Rapid and simple dissolution procedure with acidic solution was demonstrated in this study. The analytical values in the cereal grain as well as in the standard reference materials obtained by the different dissolution procedures were in good agreement within one standard deviation. The iodine in cereal grains and the standard reference materials ranged from 0.002 to 0.03 μg g^?-1 and 0.0015 to 0.30 μg g^?-1, respectively. The distribution of relative standard deviation (RSD) for iodine concentration below 0.01 μg g^?-1 were 21% and 24% of all data for the range 1–10% RSD and 11–20% RSD, respectively. The RSD for 0.1 μg g^?1 of iodine concentrations were around 10%     

Simultaneous Determination of Hydrogen Peroxide and Organic Hydroperoxides in Water

The kinetics of the reactions of H 2 O 2 and of methyl, ethyl, tert -butyl, and cumene hydroperoxides with I m were investigated in the presence and absence of molybdate as catalyst. These results were utilized to develop an analytical method for the simultaneous determination of H 2 O 2 and organic hydroperoxides in aqueous solutions. The total amount of H 2 O 2 and organic hydroperoxides can be determined by the spectrophotometric measurement of $ {\rm I}_3^ - $ formed quantitatively during 30 min of heating at 60°C. Catalase selectively decomposes H 2 O 2 in solutions containing organic hydroperoxides. The total amount of the latter can therefore be determined iodometrically after H 2 O 2 decomposition. In the oxidation of leuco crystal violet to crystal violet by H 2 O 2 and organic hydroperoxides, horseradish peroxidase exerts similar activities in the reactions involving methyl and ethyl hydroperoxides and H 2 O 2 , but its activity is much lower with tert -butyl and cumene hydroperoxide. It was observed that acetate buffer is unsuitable for pH adjustment in this type of hydroperoxide determination in consequence of the slow oxidation of the dye in the blank solution.     

Iodine-catalyzed three-component reaction of quinazoline-2,5-diones with aldehydes and styrenes for the synthesis of allylamine derivatives

Iodine-catalyzed three component reaction of quinazoline-2,5-diones, aldehydes, and styrenes provides allylamine derivatives was described. Both paraformaldehyde and ethyl glyoxalate can be applied in this reaction with simple styrenes with high regioselectivity.     

Metal-free synthesis of 1,2,3-benzotriazines

The recent molecular iodine catalyzed [1,2]-rearrangement of aryl amines and 3-amino-1H-indazolesfor the synthesis of 1,2,3-benzotriazines is highlighted.     

One-pot,direct synthesis of acyl azides from carboxylic acids using Ph2PCl/I2/NaN3 reagent system

A mild,efficient and simple method for the preparation of acyl azides from carboxylic acids using chlorodiphenylphosphine in the presence of molecular iodine and sodium azide is described.     

A reverse-flow injection analysis method for the determination of dissolved oxygen in fresh and marine waters

A reverse flow injection method (rFIA) based on the Winkler titration chemistry, is reported for the determination of dissolved oxygen (DO) in natural waters. Manganese(II) sulfate is injected into a continuously flowing stream of sample and subsequently merges with a reagent stream of sodium hydroxide and sodium iodide. Manganese(II) hydroxide that is formed reacts with DO in the sample to form an oxidized manganese hydroxyoxide floc. Addition of 10% sulfuric acid dissolves this floc, and under acidic conditions, the triiodide ion formed is detected by photometry in a flow through cell at a wavelength of 440 nm. The method is rapid (48 measurements per h), repeatable (R.S.D. ca. 3%, n=3), and has a calculated detection limit of 0.25 mg l⁻¹ (P=0.001). No interference from nitrite or ferrous ions was observed at concentrations typically found in natural waters. The method has been successfully applied to on-line measurement of DO in sediment respiration reactors.     

Iodine concentration in different human brain parts

Iodine is one of the most important essential elements as demonstrated by the fact that its deficiency can cause goitre. Nevertheless, quantitative data on its concentration in biological materials, especially in the human brain, are scarce. There is therefore a demand for accurate and reliable information on iodine in these types of samples. The purpose of the present work was to determine the concentration of total iodine in some control human brain parts by rapid radiochemical neutron activation analysis. Our second goal was to determine I distribution between lipid fraction and in brain tissue without lipid by applying two types of solvent extraction methods. The results were checked by the analysis of biological standard reference materials with certified or literature values for iodine and good agreement was found.