Spectrophotometric Determination of Carbaryl in Grains

1982 ◽  
Vol 65 (1) ◽  
pp. 32-34
Author(s):  
Kalapanda M Appaiah ◽  
Rasamsetti Ramakrishna ◽  
Kadari R Subbarao ◽  
Omprakash Kapur
Keyword(s):  
Spectrophotometric Determination ◽  
Absorption Maximum ◽  
Potassium Hydroxide ◽  
Oxidizing Agent ◽  
Spectrophotometric Measurement ◽  
The Relationship ◽  
Hydrolysis Of

Abstract A method has been developed for determining carbaryl (1-naphthyl N-methyl carbamate) in grains, based on hydrolysis of carbaryl with methanolic potassium hydroxide to 1-naphthol, reaction with 4-aminophenazone in the presence of alkaline oxidizing agent, and spectrophotometric measurement at the absorption maximum at 475 nm. The relationship between absorbance and concentration is linear in the range of 0.5-20 μg/mL. The method can be applied to levels as low as 0.3 ppm carbaryl in grains.

Spectrophotometric Determination of Methomyl Residues in Selected Vegetables, Crains, and Soil

1977 ◽  
Vol 60 (5) ◽  
pp. 1093-1096
Author(s):  
Jois R Rangaswamy ◽  
Shimoga R Prakash ◽  
Yadathora N Vijayashankar
Keyword(s):  
Spectrophotometric Determination ◽  
Absorption Maximum ◽  
Acid Treatment ◽  
Sulfanilic Acid ◽  
Benzenesulfonic Acid ◽  
The Relationship

Abstract Methomyl (S-methyl-N-[(methylcarbamoyl) oxy] thioacetimidate) is converted to oxime and hydroxylamine by alkali and acid treatment, respectively. Hydroxylamine is oxidized with iodine in the presence of sulfanilic acid to yield p-diazoniumbenzenesulfonic acid which is coupled with α-naphthylamine to form a crimson p-benzenesulfonic acid-azo-α-naphthylamine with an absorption maximum at 520 nm. The relationship between absorbance and concentration of methomyl is linear in the range 0.5–10 μg. The method is sensitive and specific; 0.625 ppm methomyl can be determined in a 40 g sample of selected vegetables, grains, and soil.

Colorimetric Determination of Propoxur and Its Residues in Vegetables

1983 ◽  
Vol 66 (1) ◽  
pp. 105-107 ◽  
Author(s):  
Kalapanda M Appaiah ◽  
Omprakash Kapur ◽  
Krishnarajpet V Nagaraja
Keyword(s):  
Absorption Maximum ◽  
Potassium Hydroxide ◽  
Colorimetric Determination ◽  
Diaminodiphenyl Sulfone ◽  
Beer's Law ◽  
Beer’S Law ◽  
Hydrolysis Of

Abstract A method has been developed for the determination of propoxur (o-isopropoxyphenyl N-methylcarbamate) based on the hydrolysis of propoxur with methanolic potassium hydroxide to its phenol and coupling with diazotized 4,4-diaminodiphenyl sulfone. The orange complex formed has an absorption maximum at 500 nm and obeys Beer’s law in the range 0.25-5.0 μg/mL. The method can be applied to levels as low as 0.5 ppm propoxur from vegetables.

Spectrophotometric Determination of Decamethrin and Its Residues in Insecticidal Formulations and in Water

1994 ◽  
Vol 77 (3) ◽  
pp. 748-751 ◽  
Author(s):  
R V Prabhakara Raju ◽  
R Raghava Naidu
Keyword(s):  
Spectrophotometric Determination ◽  
Hydrolysis Product ◽  
Spectrophotometric Methods ◽  
Alkaline Conditions ◽  
The Relationship ◽  
Hydrolysis Of

Abstract Three spectrophotometric methods were developed for the microdetermination of decamethrin in insecticidal formulations and in water. The methods are based on the hydrolysis of decamethrin with methanolic KOH to 3-phenoxybenzaldehyde; condensation of the hydrolysis product with 2,4- dinitrophenylhydrazine (2,4-DNPH), 4-nitrophenylhydrazine (4-NPH), or 2,4,6-trinitrophenylhydrazine (2,4,6-TNPH) under alkaline conditions; and measurement of the condensates at the absorption maxima of 444,535, and 480 nm, respectively. The relationship between absorbance and concentration was linear in the ranges of 0.1–5.0 μg/mL, 0.5–7.0 μg/mL and 0.1–5.5 μg/mL for 2,4-DNPH, 4-NPH, and 2,4,6-TNPH, respectively. The methods are sufficiently sensitive and can be used to detect decamethrin at concentrations as low as 0.1 μg/mL.

Benzyl ethers of methyl α-D-glucopyranoside

1980 ◽  
Vol 45 (7) ◽  
pp. 1959-1963 ◽  
Author(s):  
Dušan Joniak ◽  
Božena Košíková ◽  
Ludmila Kosáková
Keyword(s):  
Kinetic Study ◽  
Spectrophotometric Determination ◽  
Reductive Cleavage ◽  
Ether Bond ◽  
Benzyl Ethers ◽  
Acid Catalyzed ◽  
Model Substances ◽  
Hydrolysis Of

Methyl 4-O-(3-methoxy-4-hydroxybenzyl) and methyl 4-O-(3,5-dimethoxy-4-hydroxybenzyl)-α-D-glucopyranoside and their 6-O-isomers were prepared as model substances for the ether lignin-saccharide bond by reductive cleavage of corresponding 4,6-O-benzylidene derivatives. Kinetic study of acid-catalyzed hydrolysis of the compounds prepared was carried out by spectrophotometric determination of the benzyl alcoholic groups set free, after their reaction with quinonemonochloroimide, and it showed the low stability of the p-hydroxybenzyl ether bond.

DC Polarographic and Spectrophotometric Determination of Ampicillin Capsules

1980 ◽  
Vol 63 (5) ◽  
pp. 1049-1051
Author(s):  
Juan A Squella ◽  
Luis J Nunez-Vergara ◽  
Maximo Aros
Keyword(s):  
Absorption Band ◽  
Spectrophotometric Determination ◽  
Degradation Product ◽  
Uv Absorption ◽  
Acidic Hydrolysis ◽  
Average Recovery ◽  
Polarographic Wave ◽  
Spectrophotometric Methods ◽  
Hydrolysis Of

Abstract Polarographic and spectrophotometric methods are proposed for the determination of ampicillin in capsules. Acidic hydrolysis of ampicillin with 1% HCHO in 0.3N HCl yields a degradation product identified as 2-hydroxy-3-phenyl-6-methylpyrazine. This compound has a well defined UV absorption band at 380 nm and a polarographic wave at –0.55 V vs SCE, which can be used for analytical purposes. Individual capsule assays, composite assays, and recovery studies are described. The average recovery values and standard deviations (SD) for UV and polarographic determinations were 99.20% (SD 0.95) and 100.85% (SD 1.09), respectively

scholarly journals Rapid Spectrophotometric Determination of Phenoxazine

2010 ◽  
Vol 7 (2) ◽  
pp. 1001-1005
Author(s):  
Baghdad Science Journal
Keyword(s):  
Detection Limit ◽  
Spectrophotometric Determination ◽  
Acidic Medium ◽  
Absorption Maximum ◽  
Aqueous Samples ◽  
Economic Method ◽  
Beer's Law ◽  
Beer’S Law ◽  
The Stability

A rapid high sensitive and inexpensive economic method has been developed for the Determination of phenoxazine by using molecular spectrophotometry. The method is based on the oxidation of phenoxazine by potassium (meta)periodate in acidic medium. The oxidation conditions were selected to enhance the sensitivity and the stability of the pink colored species which shows an absorption maximum at 530 nm. The Beer’s law was obeyed for phenoxazine concentration range from 1 to 6 µg mL-1 with 0.003 µg mL-1 detection limit and provided variation coefficients between 0.4 to 1.7 %. This method was successfully applied for the determination of phenoxazine in aqueous samples

The Direct Spectrophotometric Determination of Protein in Cerebrospinal Fluid

1963 ◽  
Vol 9 (3) ◽  
pp. 283-295 ◽  
Author(s):  
Roman L Patrick ◽  
Ralph E Thiers
Keyword(s):  
Cerebrospinal Fluid ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Gel Filtration ◽  
Spectrophotometric Measurement ◽  
Separation Chamber ◽  
Cerebrospinal Fluid Protein

Abstract A rapid and sensitive direct spectrophotometric method for the determination of cerebrospinal fluid protein which uses as little as 0.1 ml. of sample has been described. The result is not affected by the ratio of albumin to globulin in the sample. Interfering substances are removed prior to spectrophotometric measurement with an automatic separation chamber employing the principle of gel filtration. Slight alterations of the procedure described for the measurement of protein enable one to obtain the nonprotein moiety for study or to measure proteins in other biologic fluids.

Colorimetric Method for the Determination of Ethylene Dibromide Residues in Grains and Air

1976 ◽  
Vol 59 (6) ◽  
pp. 1262-1265
Author(s):  
Jois R Rangaswamy ◽  
Yadathora N Vijayashankar ◽  
Mysore Muthu
Keyword(s):  
Colorimetric Method ◽  
Oxidizing Agent ◽  
Ethylene Dibromide ◽  
Air Sample ◽  
The Relationship ◽  
Bromo Compound

Abstract A method based on the hydrolytic debromination of ethylene dibromide (EDB) in the presence of an oxidizing agent has been developed. Bromine liberated from inorganic bromide is used to brominate p-rosaniline. The intensity of the resulting violet-red bromo compound in chloroform is measured at 580 nm. The relationship between absorbance and concentration of EDB is linear in the range of 5–60 μg. The method is very sensitive and as little as 0.50 ppm unchanged EDB residue in a 20 g sample of fumigated grain and 1 ppm EDB in a 10 ml air sample can be detected.

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