Spectrophotometric Determination of Capsaicin

1977 ◽  
Vol 60 (4) ◽  
pp. 970-972 ◽  
Author(s):  
José Jorge Ramos Palacio
Keyword(s):  
Ethyl Acetate ◽  
Rapid Method ◽  
Spectrophotometric Determination ◽  
Acetate Solution ◽  
Ethyl Acetate Solution

Abstract A rapid method has been developed for determining the pungency of hot paprika. Paprika is extracted with ethyl acetate, and an ethyl acetate solution of vanadium oxytrichloride is added just before reading at 720 nm. The method is sensitive for small quantities, i.e., less than 0.05%, and it is not necessary to isolate and purify the capsaicin.

scholarly journals Determination of Residues of Flumequine and 7-Hydroxyflumequine in Edible Sheep Tissues by Liquid Chromatography with Fluorimetric and Ultraviolet Detection

1998 ◽  
Vol 81 (3) ◽  
pp. 519-527 ◽  
Author(s):  
Jean-michel Delmas ◽  
Anne-marie Chape ◽  
Pascal Sanders
Keyword(s):  
Liquid Chromatography ◽  
Ethyl Acetate ◽  
Simultaneous Determination ◽  
Rapid Method ◽  
Active Metabolite ◽  
Fluorimetric Detection ◽  
Ultraviolet Detection ◽  
Tissue Extracts ◽  
Edible Tissues

abstract A simple, sensitive, and rapid method for simultaneous determination of residues of flumequine and its microbiologically active metabolite 7-hydroxyflumequine in 100 mg sheep edible tissues (muscle, liver, kidney, and fat) by liquid chromatography is reported. After liquid-liquid cleanup with ethyl acetate, tissue extracts were injected onto a Select B column. The 2 compounds were determined by ultraviolet and fluorimetric detection. The method was repeatable and reproducible for flumequine and 7-hydroxyflumequine in muscle, liver, kidney, and fat, with limits of detection below 2 and 3 μg/kg for flumequine and 7-hydroxyflumequine, respectively. Mean recoveries for flumequine were 90 ± 7, 82 ± 7,89 ± 5, and 82 ± 6% in muscle, liver, kidney, and fat, respectively. Mean recoveries for 7-hydroxyflumequine were 91 ± 2, 90 ± 4, 86 ± 3, and 84 ± 4% in muscle, liver, kidney, and fat, respectively.

Rapid Determination of Mono-, Di- and Tri-isopropyl Citrate in Foods by Gas Chromatography

1986 ◽  
Vol 49 (11) ◽  
pp. 914-916 ◽  
Author(s):  
SUMIKO TSUJI ◽  
YASUHIDE TONOGAI ◽  
YOSHIO ITO
Keyword(s):  
Gas Chromatography ◽  
Ethyl Acetate ◽  
Rapid Method ◽  
Rapid Determination ◽  
Milk Powder ◽  
Detection Limits ◽  
Edible Oil ◽  
Acid Condition

A simple and rapid method for determining mono-, di- and tri-isopropyl citrates in foods was developed. Isopropyl citrates in butter and milk powder were extracted with ethyl acetate under acid condition and in edible oil with hexane. The ethyl acetate containing isopropyl citrates was evaporated and the residue was taken up in hexane. The isopropyl citrates in hexane were extracted into acetonitrile. After evaporation of the solvent, isopropyl citrates were methylated with diazomethane, and they were determined by gas chromatography. Recoveries of mono-, di- and tri-isopropyl citrates from edible oil, butter and milk powder by this method were more than 92.9%, 95.7% and 94.8%, respectively. The detection limits of isopropyl citrates were 1 μg/g of sample.

scholarly journals Preparation and Photochromic Performance of Homogeneous Phase Nitrocellulose Membrane Grafting Spirooxazine Moieties

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 569
Author(s):  
Bin-Bin Sun ◽  
Bing-Hua Yao ◽  
Yang-Qing He ◽  
Bo Yang
Keyword(s):  
Ethyl Acetate ◽  
Acetate Solution ◽  
Ethyl Acetate Solution ◽  
Colored Form ◽  
Isobutyl Ketone ◽  
Photochromic Properties ◽  
Photochromic Behavior ◽  
Reaction Rate Constants ◽  
13C Nuclear Magnetic Resonance ◽  
Relative Absorption

The synthesis of 1,3,3-trimethyl-9′-acryloxyspiro[indoline-2,3′(3H)naphtho[2,1-b][l,4]-oxazine] (AISO) was carried out by catalytic esterification of 1,3,3-trimethyl-9′-hydroxyspiro-[indoline-2,3′(3H)naphtho[2,1-b][l,4]oxazine] (SO–OH) and acrylic acid in the presence of 1,3-dicyclohexylcarbodiimide (DCC) and N-dimethylaminopyridine (DMAP). Then, the synthesis of the target copolymer (NC-g-AISO) was was carried out by benzoyl peroxide (BPO)-induced graft copolymerization of the AISO monomer onto nitrocellulose (NC) in a homogeneous methyl isobutyl ketone medium. The structure of NC-g-AISO was characterized by Fourier transform infrared (IR) spectroscopy, 13C Nuclear Magnetic Resonance (NMR) spectra and thermogravimetric (TG) analysis. The photochromic properties of NC-g-AISO were investigated by examining UV–Vis spectra in ethyl acetate solution and solid membrane. Compared with the AISO monomer in ethyl acetate solution, the thermal color decay stability of the colored form of NC-g-AISO in ethyl acetate solution and in solid membrane improved significantly. The thermal color decay reaction rate constants in ethyl acetate solution and membrane at 25 °C were 1.77 × 10–2 and 1.36 × 10–3 s–1, respectively, fitted using the first-order reaction equation. After ten photochromic cycles, the relative absorption intensity of the colored form of NC-g-AISO decreased by 0.85%, indicating that the NC-g-AISO membrane has good reversible photochromic behavior.

scholarly journals Spectrophotometric Determination of Ritodrine and Isoxsuprine Hydrochlorides Using 4-Aminoantipyrine

2000 ◽  
Vol 83 (6) ◽  
pp. 1440-1445 ◽  
Author(s):  
Hosakere D Revanasiddappa ◽  
Bochhe Gowda Manju
Keyword(s):  
Quantitative Determination ◽  
Rapid Method ◽  
Spectrophotometric Determination ◽  
Dosage Forms ◽  
Oxidizing Agent ◽  
Ritodrine Hydrochloride ◽  
Colored Product

Abstract A simple, accurate, and rapid method for the quantitative determination of ritodrine hydrochloride (RTH) and isoxsuprine hydrochloride (ISH) in both pure and dosage forms, is described. The method is based on the development of pink colored product as a result of the condensation of 4-aminoantipyrine with phenols in the presence of an alkaline oxidizing agent. The resulting products are measured at 510 nm for both drugs, with molar absorptivities of 0.98 × 104 and 1.20 × 104 L/mol·cm for RTH and ISH, respectively. A study of the effect of commonly associated excipients revealed that they did not cause interference.

Spectrophotometric Determination of Several Bible Acids as Conjugates. Extraction with Ethyl Acetate

1961 ◽  
Vol 33 (10) ◽  
pp. 1407-1411 ◽  
Author(s):  
S. J. Levin ◽  
C. G. Johnston ◽  
A. J. Boyle
Keyword(s):  
Ethyl Acetate ◽  
Spectrophotometric Determination

Rapid method for the spectrophotometric determination of iridium(IV)

The Analyst ◽  
1985 ◽  
Vol 110 (8) ◽  
pp. 1027 ◽  
Author(s):  
Boregowda Keshavan ◽  
Padmarajaiah Nagaraja
Keyword(s):  
Rapid Method ◽  
Spectrophotometric Determination

Spectrophotometric Determination of Cyclamate in Foods: NMKL Collaborative Study

1987 ◽  
Vol 70 (3) ◽  
pp. 588-590
Author(s):  
Anna-Maija K Sjoberg ◽  
Timo A Alanko
Keyword(s):  
Aqueous Solution ◽  
Ethyl Acetate ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Collaborative Study ◽  
Soft Drinks ◽  
Uv Absorption ◽  
Acidic Aqueous Solution ◽  
Coefficients Of Variation

Abstract A spectrophotometric method for the determination of cyclamate was collaboratively studied in 9 laboratories. Ethyl acetate is added to extract cyclamate from acidic aqueous solution into water, and the cyclamate is then quantitatively converted to /V,./V-dichlorocyclohexylamine by adding excess hypochlorite. A',A'-Dichlorocyclohexylamine is determined by measuring its UV absorption at 314 nm. Six samples, 3 soft drinks with cyclamate levels of 0.36-0.47 g/kg and 3 jams with levels of 1.23-1.50 g/kg, were included in the study. Average recoveries of cyclamate were 99.7% in the soft drinks and 103.8% in the jams. Reproducibility coefficients of variation were 6.7% for the soft drinks and 4.4% for the jams.

Sign in / Sign up

Export Citation Format

Share Document