Spectrophotometric Determination of Dehydroacetic Acid in Fruits and Vegetables

1973 ◽  
Vol 56 (5) ◽  
pp. 1270-1272
Author(s):  
Theodore S Piwowar
Keyword(s):  
Glass Fiber ◽  
Spectrophotometric Determination ◽  
Silicic Acid ◽  
Fruits And Vegetables ◽  
Chloroform Extract ◽  
Average Recovery ◽  
Ultraviolet Absorbance ◽  
Dehydroacetic Acid ◽  
Fiber Sheet

Abstract A method for the determination of the preservative dehydroacetic acid (DHA) in strawberries, bananas, and zucchini squash is described. The samples are blended and extracted with chloroform. The chloroform extract is cleaned up on a preparatory silicic acid-glass fiber sheet. The DHA is determined by its ultraviolet absorbance at 307 nm. The average recovery of DHA added at levels of 5 to 80 ppm was 100.2 ±4.8% (15 analyses). The method is sensitive to 2 ppm DHA.

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

Determination of Sevin Insecticide Residues in Fruits and Vegetables

1964 ◽  
Vol 47 (2) ◽  
pp. 283-286
Author(s):  
D P Johnson
Keyword(s):  
Fruits And Vegetables ◽  
Collaborative Study ◽  
Colorimetric Determination ◽  
Average Recovery ◽  
Insecticide Residues ◽  
Chromogenic Agent ◽  
Hydrolysis Of ◽  
Concentration Levels ◽  
Good Agreement

Abstract Collaborative study of a method for Sevin insecticide residues was repeated with apples and lettuce as test crops. The method is based on alkaline hydrolysis of Sevin and colorimetric determination of the resulting 1-naphthol with p-nitrobenzenediazonium fluoborate as chromogenic agent. Data from 5 collaborators were in good agreement with an average recovery of 87.8% at 2 concentration levels. It is recommended that the method be adopted as official, first action.

Spectrophotometric Determination of Cyclamate in Soft Drinks and Desserts: Complementary Collaborative Study

1988 ◽  
Vol 71 (6) ◽  
pp. 1212-1214
Author(s):  
Anna-Maija K SJÖBERG
Keyword(s):  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Soft Drink ◽  
Collaborative Study ◽  
Soft Drinks ◽  
Food Control ◽  
Average Recovery ◽  
Relative Standard ◽  
Standard Deviations

Abstract Fifteen official food control laboratories participated in a collaborative study of a spectrophotometric method to determine cyclamate in a soft drink and a dessert at concentrations of 90-311 mg/L and 202-526 mg/kg, respectively, with blind duplicates and a blank. Average recovery from the soft drink was 97.5%, and from the dessert, 98.6%. Reproducibility relative standard deviations were 4.7-6.5% and 6.9-8.5%, respectively. The outlier percentage was 5.5%. This study complements an earlier work by leading Nordic food laboratories and was designed according to the latest recommendations. The results of this study were compared with those of the earlier collaborative study and with general collaborative results obtained by AOAC.

Atomic Absorption Spectrophotometric Determination of Dibutyltin Dilaurate in Finished Feeds

1973 ◽  
Vol 56 (6) ◽  
pp. 1480-1482
Author(s):  
Glenn M George ◽  
Marven A Albrecht ◽  
Larry J Frahm ◽  
J Patrick McDonnell
Keyword(s):  
Atomic Absorption ◽  
Spectrophotometric Determination ◽  
Chloroform Extract ◽  
Methanol Solution ◽  
Atomic Absorption Spectrophotometer ◽  
Dibutyltin Dilaurate ◽  
Instrument Response ◽  
Mixed Feeds

Abstract Dibutyltin dilaurate is extracted from finished feed with warm chloroform. The chloroform extract is filtered and a 25 ml aliquot is concentrated in the presence of methanol until all traces of chloroform are removed. The methanol solution is diluted and feed interferences are removed by filtration. The filtered solution is aspirated into an atomic absorption spectrophotometer with a triple-slot burner head, using an air-acetylene flame. The instrument response to tin at 286.3 nm is recorded. Essentially theoretical recovery (100.5— 101.9%) has been obtained for tin in laboratory-mixed feeds.

scholarly journals Spectrophotometric Determination of Silicic Acid by Flow Injection Analysis

1982 ◽  
Vol 55 (11) ◽  
pp. 3477-3481 ◽  
Author(s):  
Takushi Yokoyama ◽  
Yukio Hirai ◽  
Norimasa Yoza ◽  
Toshikazu Tarutani ◽  
Shigeru Ohashi
Keyword(s):  
Spectrophotometric Determination ◽  
Silicic Acid ◽  
Flow Injection ◽  
Flow Injection Analysis

Spectrophotometric determination of ammonia-nitrogen after preconcentration as indothymol on a glass-fiber filter in the presence of a cationic surfactant

1992 ◽  
Vol 106 (1-2) ◽  
pp. 101-108 ◽  
Author(s):  
Noriko Hata ◽  
Kaoru Teraguchi ◽  
Mutsumi Yamaguchi ◽  
Issei Kasahara ◽  
Shigeru Taguchi ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Cationic Surfactant ◽  
Spectrophotometric Determination ◽  
Ammonia Nitrogen ◽  
Glass Fiber Filter ◽  
Fiber Filter

Manual and Semiautomated Spectrophotometric Determination of Vitamin K3 by Reactions with Piperidine and Malononitrile

1981 ◽  
Vol 64 (3) ◽  
pp. 611-615 ◽  
Author(s):  
Saad S M Hassan
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Determination ◽  
Maximum Absorption ◽  
Vitamin K3 ◽  
Average Recovery ◽  
Spectrophotometric Methods ◽  
Reduced Forms

Abstract Simple, rapid, selective, and sensitive spectrophotometric methods are described for manual and semiautomated determination of vitamin K3. These methods are based on reactions with piperidine and malononitrile whereby intense red and blue colors with maximum absorption at 510 nm (E1%1cm 150) and 580 nm (E1%1cm 155), respectively, are developed. The reactions are sensitive enough to permit the determination of 2-100 μg vitamin K3/mL with an average recovery of 98% and a standard deviation of 1%. There is no interference from vitamins K1 and K2, and the reduced forms of K vitamins, or from many common pharmaceutical diluents and additives.

Spectrophotometric Determination of Codeine in Terpin Hydrate Elixir

1965 ◽  
Vol 48 (3) ◽  
pp. 607-608
Author(s):  
Charles Milos
Keyword(s):  
Acetic Acid ◽  
Stationary Phase ◽  
Spectrophotometric Determination ◽  
Acid Complex ◽  
Average Recovery ◽  
Toluenesulfonic Acid

Abstract In the proposed method for codeine in terpin hydrate elixir, p-toluenesulfonic acid and a sample of elixir are incorporated as a stationary phase on a partition chromatogram. Elution with large quantities of ether removes everything but the codeine-p-toluenesulfonic acid complex, which is eluted with chloroform-acetic acid in four steps. The complex is passed over a column containing NaHCO3 as stationary phase, yielding the isolated codeine. Codeine is determined quantitatively from absorption at 278 mμ. The average recovery of codeine reported by the collaborators was 99%.

Collaborative Study of a Spectrophotometric Determination of Ferric, Ferrous, and Total Iron in Drugs by Reaction with α,α′-Dipyridyl

1977 ◽  
Vol 60 (6) ◽  
pp. 1350-1354
Author(s):  
Daniel J Sullivan
Keyword(s):  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Total Iron ◽  
Average Recovery ◽  
Average Coefficient ◽  
Iron Preparation ◽  
Colorimetric Reagent

Abstract A spectrophotometric method for determining Fe2+, Fe3+, and total Fe in drugs has been developed, using α, α′-dipyridyl as the colorimetric reagent. The method is applicable to tablets, elixirs, injectables, and bulk powders. Eight collaborators analyzed a synthetic iron preparation and 7 commercial samples. For the synthetic iron preparation, the average recovery was 100.3% and the coefficient of variation was 1.02%. For 7 commercial samples, the average coefficient of variation was 1.44%. The method has been adopted as official first action.

Comparison of Florisil and ChromAR Sheet Cleanup Procedures on Spinach Extracts for Multiple Chlorinated Pesticide Residues Analysis

1970 ◽  
Vol 53 (5) ◽  
pp. 1010-1014
Author(s):  
Thomas H Beasley ◽  
Howard W Ziegler
Keyword(s):  
Glass Fiber ◽  
Silicic Acid ◽  
Pesticide Residues ◽  
Chlorinated Pesticides ◽  
Florisil Column ◽  
Column Method ◽  
Cleanup Procedure ◽  
Fiber Sheet ◽  
Column Procedure

Abstract An improved cleanup procedure for fresh spinach extracts, using silicic acid-glass fiber sheet, was compared directly with the activated Florisil column procedure. The new cleanup method requires about one-half the time necessary for the Florisil column method. The pesticide concentrates were analyzed by quantitative GLC, using a 2’ column of OV–17 and a 90Sr detector. Recovery experiments on 100 g samples fortified with 4 major chlorinated pesticides showed the 2 methods to be comparable.

Sign in / Sign up

Export Citation Format

Share Document