Determination of Carbaryl Residues in Honey Bees

1965 ◽  
Vol 48 (4) ◽  
pp. 771-774
Author(s):  
D P Johnson ◽  
H A Stansbury
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Quantitative Determination ◽  
Honey Bees ◽  
Methylene Chloride ◽  
Hydrolysis Product ◽  
Separate Analysis ◽  
Yellow Substance ◽  
Hydrolysis Of

Abstract A method has been developed for detecting residues of carbaryl (1-naphthyl methylcarbamate) as well as its hydrolysis product, 1-naphthol, in dead bees. The method is based on extraction of the bees with benzene, followed by a cleanup involving liquid partitioning and chromatography on Florisil. The quantitative determination involves hydrolysis of carbaryl to 1-naphthol and coupling of the latter with p-nitrobenzenediazonium fluoborate in acetic acid to form a yellow substance. For separate analysis, free 1-naphthol is separated from methylene chloride into a basic aqueous solution. The sensitivity of the method is about 0.1 ppm; recoveries averaged 85.6 ± 6.6% for 1- naphthol and 83.8 ± 2.7% for carbaryl.

DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

QUANTITATIVE DETERMINATION OF CURCUMIN IN TURMERIC POWDER AND TURMERIC–HONEY BALL PILLS BY HPLC

2018 ◽  
Vol 8 (4) ◽  
pp. 42-47
Author(s):  
Tien Nguyen Huu ◽  
Tram Le Thi Bao ◽  
Ngoc Nguyen Thi Nhu ◽  
Thang Phan Phuoc ◽  
Khan Nguyen Viet
Keyword(s):  
Acetic Acid ◽  
Gastric Mucosa ◽  
Quantitative Determination ◽  
Mobile Phase ◽  
Curcuma Longa ◽  
Biological Marker ◽  
Hplc Method ◽  
Chromatography Analysis ◽  
Precision And Accuracy

Background: Curcumin is a major ingredient in turmeric (Curcuma longa L., Zingiberaceae), which has important activities such as anti-tumor, anti-inflammatory, antioxidant, anti-ischemia, protection of gastric mucosa etc,. Curcumin can be considered as a biological marker of turmeric and turmeric products. Objectives: Developing an HPLC method for quantification of curcumin in turmeric powder and turmeric - honey ball pills; applying this method for products on the market. Materials and methods: turmeric powder and turmeric - honey ball pills collected in Thua Thien Hue province. After optimization process, the method was validated and applied to evaluate the content of curcumin. Results: The chromatography analysis was performed with: Zorbaz Eclipse XDB-C18 (150 × 4.6 nm; 5 µm); Mobile phase: acetonitril: 2% acetic acid (45:55), Flow rate was kept constant at 1.0 ml/min; Detector PDA (420 nm). The method was validated for the HPLC system compatibility, specificity, linearity range, precision and accuracy; the recovery greater than 98%. Conclusion: The developed HPLC method can determine curcumin in turmeric powder and turmeric - honey ball pills. Key words: Curcumin, turmeric powder, turmeric-honey ball pills, quantitative determination, HPLC

Enzymatic colorimetry of lecithin and sphingomyelin in aqueous solution.

1983 ◽  
Vol 29 (8) ◽  
pp. 1513-1517 ◽  
Author(s):  
M W McGowan ◽  
J D Artiss ◽  
B Zak
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Amniotic Fluid ◽  
Enzymatic Reaction ◽  
Detergent Solution ◽  
Enzymatic Determination ◽  
Red Color ◽  
Hydrolysis Of ◽  
Zwitterionic Detergent

Abstract A procedure for the enzymatic determination of lecithin and sphingomyelin in aqueous solution is described. The phospholipids are first dissolved in chloroform:methanol (2:1 by vol), the solvent is evaporated, and the residue is redissolved in an aqueous zwitterionic detergent solution. The enzymatic reaction sequences of both assays involve hydrolysis of the phospholipids to produce choline, which is then oxidized to betaine, thus generating hydrogen peroxide. The hydrogen peroxide is subsequently utilized in the enzymatic coupling of 4-aminoantipyrine and sodium 2-hydroxy-3,5-dichlorobenzenesulfonate, an intensely red color being formed. The presence of a non-reacting phospholipid enhances the hydrolysis of the reacting phospholipid. Thus we added lecithin to the sphingomyelin standards and sphingomyelin to the lecithin standards. This precise procedure may be applicable to determination of lecithin and sphingomyelin in amniotic fluid.

scholarly journals Kinetics and Mechanism of Hydrolysis of Acetylthiocholine by Butyrylcholine Esterase

2002 ◽  
Vol 57 (11-12) ◽  
pp. 1072-1077 ◽  
Author(s):  
Karel Komers ◽  
Alexandr Čegan ◽  
Marek Link
Keyword(s):  
Acetic Acid ◽  
Kinetics And Mechanism ◽  
Kinetics Parameters ◽  
Mechanism Of Hydrolysis ◽  
Ph Stat ◽  
Stat Method ◽  
Ellman’S Method ◽  
Hydrolysis Of

Kinetics and mechanism of hydrolysis of acetylthiocholine by the enzyme butyrylcholine esterase was studied. The spectrophotometric Ellman’s method and potentiometric pH-stat method were used for continuous determination of the actual concentration of the products thiocholine and acetic acid in the reaction mixture. The validity of the Michaelis-Menten (Briggs-Haldane) equation in the whole course of the reaction under used conditions was proved. The corresponding kinetics parameters (Vm and KM) were calculated from the obtained dependences of concentration of thiocholine or acetic acid vs. time and compared. From this comparison the deciding kinetic role of the step producing thiocholine was derived. The values of initial molar concentration of the enzyme and of the rate constants of the kinetic model were estimated.

Determination of Plant Hormone Indole-3-Acetic Acid in Aqueous Solution

2012 ◽  
Vol 25 (1) ◽  
pp. 303-307 ◽  
Author(s):  
Jana Bulíčková ◽  
Romana Sokolová ◽  
Stefania Giannarelli ◽  
Beatrice Muscatello
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Plant Hormone ◽  
Indole 3 Acetic Acid

Ultraviolet Spectroscopic Determination of Five Lanthanide Elements without Prior Separation

1993 ◽  
Vol 47 (6) ◽  
pp. 764-772 ◽  
Author(s):  
Irvin M. Citron ◽  
Patrick M. Hanlon ◽  
Stephen Arthur
Keyword(s):  
Aqueous Solution ◽  
Quantitative Determination ◽  
Heavy Metal Ions ◽  
Lanthanide Ions ◽  
Ion Concentrations ◽  
Statistical Reliability ◽  
Modified Method ◽  
Lanthanide Elements ◽  
The Individual

This investigation has resulted in an analytical method for the quantitative determination of total lanthanide concentration in aqueous solution by absorbance at 240 nm in the ultraviolet followed by quantitative determination of individual lanthanide ion concentrations by the use of concentration-responsive absorption peaks in the 190–235 nm region. The 240-nm peak is present and is proportional to concentration regardless of the ligand employed to complex the lanthanides (including H2O). The individual lanthanide/ligand peaks in the 190–235 nm region were selected on the basis of their separation from one another, their linearity of absorbance vs. concentration, and their statistical reliability based on replicate sample analyses. Lanthanides involved in this investigation were La+3, Nd+3, Eu+3, Ho+3, and Yb+3. Ligands ultimately selected for complexation were citrate for La+3, Nd+3, and Ho+3, and DTPA for Eu+3, Ho+3, and Yb+3. When large amounts of heavy metal ions were present, a modified method was developed with citrate as the only complexing ligand for all five lanthanides. The method here developed permits the analyses of lanthanide ions in aqueous solution without prior separation and involves the use of comparatively inexpensive instrumentation (UV absorption spectrophotometer).

scholarly journals FLUORESCENCE ENHANCEMENT OF Al3+– SODIUM MORIN–5–SULFONATE COMPLEX BY IMIDAZOLIUM IONIC LIQUID AND ITS APPLICATION IN DETERMINATION OF Al3+ IONS IN AN AQUEOUS SOLUTION

2019 ◽  
Vol 81 (2) ◽  
Author(s):  
Syaza Atikah Nizar ◽  
Nurul Syamimi Abdul Satar ◽  
Shaik Azri Shaik Amar ◽  
Fatin Hazirah Abdullah ◽  
Faizatul Shimal Mehamod ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquid ◽  
Acetic Acid ◽  
Ternary Complex ◽  
Fluorescence Enhancement ◽  
Calibration Graph ◽  
Fluorescence Signal ◽  
Binary Complex ◽  
Imidazolium Ionic Liquid

This study describes the preparation of sodium morin–5–sulfonate (NaMSA) as a new reagent for the determination of aluminium(III) (Al3+) ions based on the formation of a ternary complex. The complex consists of Al3+, NaMSA, and 1–Butyl–3–methylimidazolium hexafluorophosphate (BMIM–PF6). It was found that this method was sensitive compared to the binary complex of Al3+ and NaMSA. The ternary complex was excited at 420 nm, and the fluorescence signal was measured at 518 nm. Maximum fluorescence signal produced at pH 5.0 (acetic acid–acetate buffer), with 0.02% v/v BMIM–PF6 and 1.0 × 10-4 molL-1 of NaMSA. The calibration graph in linear up to 10 mgL-1 with the calculated detection limit of 0.017 mgL-1. Effect of foreign ions towards the ternary complex was also studied. Finally, the method was applied in the determination of Al3+ ions in water samples, and satisfactory results were obtained.

Quantitative determination of thiourea in aqueous solution in the presence of sulphur dioxide by Raman spectroscopy

The Analyst ◽  
1986 ◽  
Vol 111 (5) ◽  
pp. 539 ◽  
Author(s):  
Heather J. Bowley ◽  
Elizabeth A. Crathorne ◽  
Donald L. Gerrard
Keyword(s):  
Aqueous Solution ◽  
Raman Spectroscopy ◽  
Quantitative Determination ◽  
Sulphur Dioxide
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