Colorimetric Determination of Carbaryl in Apple, Lettuce, Chard, and Tomato

1971 ◽  
Vol 54 (5) ◽  
pp. 1083-1085
Author(s):  
Maria H C K De Riveros ◽  
Eugenio E Vonesch
Keyword(s):  
Methylene Chloride ◽  
Zinc Hydroxide ◽  
Colorimetric Determination ◽  
Color Complex

Abstract A direct Spectrophotometric technique for determination of carbaryl in apple, lettuce, chard, and tomato has been developed, based on formation of a specific color complex with diazotized 2,5-dichloroaniline sulfate. Carbaryl is extracted with methylene chloride, concentrated, and cleaned up with zinc hydroxide. The color produced with diazotized 2,5-dichloroaniline is measured at 510 nm. Recoveries of added carbaryl from the 4 crops tested ranged from 89.6 to 105%.

Collaborative Study of the Colorimetric Determination of Nitrate and Nitrite in Cheese

1976 ◽  
Vol 59 (2) ◽  
pp. 284-288
Author(s):  
James E Hamilton
Keyword(s):  
Azo Dye ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Sulfanilic Acid ◽  
Zinc Hydroxide ◽  
Colorimetric Determination ◽  
Standard Curve ◽  
Nitrite Nitrate ◽  
Nitrate And Nitrite

Abstract A quantitative colorimetric method for the determination of nitrate and nitrite in cheese has been subjected to collaborative study. The method includes clarification of an aqueous extract of cheese with zinc hydroxide, reduction of nitrate to nitrite via a spongy cadmium column (the nitrite originally present is unaltered), diazotization of sulfanilic acid with the nitrite, and coupling with 1-naphthylamine hydrochloride to form a pink azo dye whose absorbance is measured at 522 nm. The spectrophotometric responses are compared to a standard curve. In samples containing both nitrate and nitrite, nitrate is determined by difference. A standard deviation of 5.5 was obtained (5 of 6 collaborators) when a cheese sample spiked with 276 ppm sodium nitrate was analyzed by the method. The method has been adopted as official first action.

A New Simple Semimicro Method for Colorimetric Determination of Urea

1963 ◽  
Vol 9 (1) ◽  
pp. 102-108 ◽  
Author(s):  
J J Coulombe ◽  
L Favreau
Keyword(s):  
Acid Medium ◽  
Rapid Method ◽  
Room Temperature ◽  
Colorimetric Determination ◽  
Red Color ◽  
Color Complex ◽  
Blood Filtrate ◽  
Diacetyl Monoxime

Abstract A new simple and rapid method for quantitative semimicro determination of blood urea is presented. Diacetyl monoxime and thiosemicarbazide form in acid medium with urea a red color complex with a maximum adsorption at 530 mµ stable at room temperature and requiring 0.2 ml. of 1:10 blood filtrate.

Colorimetric Determination of Bismuth in Bismuth Subsalicylate Oil Suspension

1963 ◽  
Vol 46 (4) ◽  
pp. 649-651
Author(s):  
Salvatore J Pinella
Keyword(s):  
Sesame Oil ◽  
Colorimetric Determination ◽  
Final Solution ◽  
Bismuth Subsalicylate ◽  
Thiourea Complex ◽  
Ether Extraction ◽  
Thiourea Solution ◽  
Color Complex ◽  
Official Methods Of Analysis

Abstract A study was made of a colorimetric determination of bismuth in bismuth subsalicylate oil suspension, similar to that of Official Methods of Analysis. The method depends upon the formation of a yellow bismuth-thiourea complex which exhibits maximum absorption at 465 mμ. Sesame oil is removed by ether extraction after HNO3 hydrolysis and the bismuth nitrate formed is converted to bismuth-thiourea complex with 2.5% thiourea solution in HNO3 (1 + 9). The color complex is stable and follows Beer’s law. The method is comparatively specific for bismuth, since only vanadium and antimony give similar color. It is satisfactory at concentrations as low as 50 μg of bismuth in the final solution. Nine collaborators reported favorable results; it is recommended that the method be adopted as official, first action.

scholarly journals Colorimetric Determination of Disulfiram in Tablets: Collaborative Study

1981 ◽  
Vol 64 (3) ◽  
pp. 554-556 ◽  
Author(s):  
Edward J Wojtowicz ◽  
◽  
J P Harms ◽  
R H Johnson ◽  
A Lazar ◽  
...  
Keyword(s):  
Chloride Solution ◽  
Methylene Chloride ◽  
Collaborative Study ◽  
Colorimetric Determination ◽  
Iodometric Titration ◽  
Tablet Form ◽  
Titration Procedure ◽  
Methylene Chloride Solution ◽  
Colorimetric Reaction

Abstract The colorimetric reaction of cuprous iodide and disulfiram has been collaboratively studied in 8 laboratories to determine the drug in tablet form at 2 dosage levels. The disulfiram was extracted from the tablet matrix with methylene chloride. After a basic wash with 1 M NaOH, an aliquot of the methylene chloride solution was reacted with solid cuprous iodide, and the absorbance of the resulting color was measured. Single assays on 2 synthetic preparations of known disulfiram content were performed with average recoveries of 98.4 and 99.2% for 93.3 and 105.3mg, respectively. Duplicate determinations on 2 commercial tablet preparations declared at 250 and 500 mg gave mean and standard deviation values of 246.6 ± 6.40 and 493.6 ± 12.0 mg, respectively. The results agreed closely with those obtained by the author using the NF iodometric titration procedure. The method has been adopted official first action.

A Method for the Colorimetric Determination of β-Glucuronidase in Urine, Serum, Tissue; Assay of Enzymatic Activity in Health and Disease

1959 ◽  
Vol 36 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Julius A. Goldbarg ◽  
Esteban P. Pineda ◽  
Benjamin M. Banks ◽  
Alexander M. Rutenburg
Keyword(s):  
Enzymatic Activity ◽  
Colorimetric Determination ◽  
Health And Disease ◽  
Urine Serum

Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline

2013 ◽  
Vol 12 (7) ◽  
pp. 460-465
Author(s):  
Sameer Amereih ◽  
Zaher Barghouthi ◽  
Lamees Majjiad
Keyword(s):  
Drinking Water ◽  
Detection Limit ◽  
Complex Formation ◽  
Molar Absorptivity ◽  
Colorimetric Determination ◽  
Zirconium Complex ◽  
Reliable Determination ◽  
Percentage Recovery ◽  
Quantitation Limit

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.

Colorimetric Determination of Amoxicillin in Pure and some Pharmaceutical Formulations Via Reaction with Potassium Permanganate as Oxidant Reagent

2019 ◽  
Vol 10 (02) ◽  
Author(s):  
Abbas Shebeeb Al-kadumi ◽  
Sahar Rihan Fadhel ◽  
Mohammed Abdullah Ahmed ◽  
Luma Amer Musa
Keyword(s):  
Potassium Permanganate ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Atomic Emission ◽  
Basic Medium ◽  
Photometric Method ◽  
Colorimetric Determination ◽  
Spectrophotometric Methods ◽  
Label Claim

We proposed two simple, rapid, and convenient spectrophotometric methods are described for the determination of Amoxicillin in bulk and its pharmaceutical preparations. They are based on the measurement of the flame atomic emission of potassium ion (in first method) and colorimetric determination of the green colored solution for manganite ion at 610 nm formed after reaction of Amoxicillin with potassium permanganate as oxidant agent (in the second method) in basic medium. The working conditions of the methods were investigated and optimized. Beer's law plot showed a good correlation in the concentration range of 5-45 μg/ml. The detection limits and relative standared deviations were (2.573, 2.814 μg/ml) (2.137, 2.498) for the flame emission photometric method and (1.844, 2.016 μg/ml) (1.645,1.932) for colorimetric methods for capsules and suspensions respectively. The methods were successfully applied to the determination of Amoxicillin in capsules and suspensions, and the obtained results were in good agreement with the label claim. No interference was observed from the commonly encountered additives and expectancies.

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