Examination of Conditions for the Determination of Carbamate Pesticides in Soils

1992 ◽  
Vol 57 (8) ◽  
pp. 1632-1638 ◽  
Author(s):  
Věra Tatarkovičová ◽  
Zdeněk Stránský
Keyword(s):  
Activated Carbon ◽  
Solvent Extraction ◽  
Soil Type ◽  
Extraction Procedure ◽  
Purification Procedure ◽  
Factors Affecting ◽  
Carbamate Pesticides ◽  
Rp Hplc ◽  
Extracting Solvent

The procedure for the determination of carbamate pesticides in soil was optimized. The following factors affecting the final results were investigated: extracting solvent, extraction procedure, extract purification procedure, and soil type. Triple extraction with acetone and purification of the extract on a two-stage purification column containing an activated carbon-silica gel 1+1 mixture were found optimal. The extracts after treatment were analyzed by RP-HPLC with UV detection. The method developed allows carbamate pesticides in soil to be determined at concentrations in excess of 30 μg kg-1.

Gas-Liquid Chromatographic Determination of Dioxathion and Quintiofos in Organophosphorus Dip Washes

1980 ◽  
Vol 63 (1) ◽  
pp. 33-36
Author(s):  
Molly I Keating
Keyword(s):  
Solvent Extraction ◽  
Extraction Procedure ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Phosphorus Compounds ◽  
Ionization Detector ◽  
Liquid Chromatographic Determination ◽  
Gasliquid Chromatography ◽  
Liquid Chromatographic

Abstract A rapid method for the analysis of dip washes is described which eliminates the usual solvent extraction procedure. The dip wash is initially diluted with acetone and then with petroleum ether. The diluted dip wash is analyzed by gasliquid chromatography, using an alkali ionization detector sensitive to phosphorus compounds. The method was applied to the determination of dioxathion (2,3-ρ-dioxanedithiol S,S-bis(O,O-diethyl phosphorodithioate)), and quintiofos (O-ethyl O-8-quinolyl phenylphosphonothioate) dip washes. Average recoveries from fouled dip washes were 100 and 104%. GLC of these compounds with an internal standard is described, which improves the precision of the method to ±2%.

Method Validation for the Quantitative Analysis of Aflatoxins (B1, B2, G1, and G2) and Ochratoxin A in Processed Cereal-Based Foods by HPLC with Fluorescence Detection

2015 ◽  
Vol 98 (4) ◽  
pp. 939-945 ◽  
Author(s):  
Işil Gazioğlu ◽  
Ufuk Kolak
Keyword(s):  
Quantitative Analysis ◽  
Simultaneous Determination ◽  
Ochratoxin A ◽  
Fluorescence Detection ◽  
Aflatoxin B1 ◽  
Hplc Analysis ◽  
Extraction Procedure ◽  
Immunoaffinity Column ◽  
Rp Hplc

Abstract Modified AOAC 991.31 and AOAC 2000.03 methods for the simultaneous determination of total aflatoxins (AFs), aflatoxin B1, and ochratoxin A (OTA) in processed cereal-based foods by RP-HPLC coupled with fluorescence detection were validated. A KOBRA® Cell derivatization system was used to analyze total AFs. One of the modifications was the extraction procedure of mycotoxins. Both AFs and OTA were extracted with methanol–water (75 + 25, v/v) and purified with an immunoaffinity column before HPLC analysis. The modified methods were validated by measuring the specificity, selectivity, linearity, sensitivity, accuracy, repeatability, reproducibility, recovery, LOD, and LOQ parameters. The validated methods were successfully applied for the simultaneous determination of mycotoxins in 81 processed cereal-based foods purchased in Turkey. These rapid, sensitive, simple, and validated methods are suitable for the simultaneous determination of AFs and OTA in the processed cereal-based foods.

scholarly journals The Hydrophobic Effect in the Adsorption Process of Alkyltrimethylammonium Bromides on to Activated Carbon

1998 ◽  
Vol 16 (7) ◽  
pp. 557-564 ◽  
Author(s):  
Jinben Wang ◽  
Yao Lu ◽  
Buxing Han ◽  
Ming Dai ◽  
Haike Yan ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Process ◽  
Hydrophobic Effect ◽  
Carbon Surface ◽  
Thermodynamic Quantities ◽  
Factors Affecting ◽  
Alkyltrimethylammonium Bromides ◽  
Different Temperatures ◽  
Surface Measurements

This paper describes the hydrophobic effect in the process of adsorption of alkyltrimethylammonium bromides from aqueous solution on to an activated carbon surface. Measurements of the adsorption isotherms of a series of alkyltrimethylammonium bromides with different hydrocarbon tail lengths at the activated carbon surface were carried out. In order to investigate the temperature dependence of the adsorption process, the determination of the adsorption of cetyltrimethylammonium bromide (CTAB) was undertaken at different temperatures in the range 20–60°C. From the experimental results obtained, the relevant thermodynamic quantities have been calculated. The role played by the hydrophobic effect in the adsorption process of cationic surfactants on to activated carbon and the factors affecting the adsorption mechanism were discussed.

scholarly journals Development and ICH Validation of a RP-HPLC-UV Method for the Quantification of Thimerosal in Topic Creams

2017 ◽  
Vol 60 (4) ◽  
Author(s):  
Guadalupe Pérez-Caballero ◽  
Nancy Muro-Hidalgo ◽  
Elvia Adriana Morales-Hipólito ◽  
Alma Villaseñor ◽  
Raquel López-Arellano
Keyword(s):  
Phosphate Buffer ◽  
Limit Of Detection ◽  
Extraction Procedure ◽  
Reversed Phase ◽  
Sample Treatment ◽  
Limit Of Quantification ◽  
Rp Hplc ◽  
Validation Parameters ◽  
Quality Control Tool

A reversed phase high-performance liquid chromatography (RP-HPLC) method for determination of Thimerosal (TMS) in topical creams was optimized and validated according to the ICH guidelines which include accuracy, precision, selectivity, robustness, limit of detection (LOD), limit of quantification (LOQ), linearity and range. For topical creams, sample treatment is often an overwhelming step essentially due to its oily nature. For the first time a simple and robust extraction procedure for TMS using phosphate buffer (pH 5.5, 0.2M) was successfully developed. This method describes the TMS quantitation by HPLC in a topical product containing 0.01% fluocinolone acetonide (FLA) as the active molecule. The HPLC separation was achieved on a Column Symmetry® and a methanol: phosphate buffer (pH 2.5, 0.05M) 70:30 v/v mobile phase and wavelength 218 nm. Results from both standards and samples showed adequate validation parameters. Noteworthy, linearity was within the range 1.2 - 2.8 μg/mL. Additionally, robustness and TMS stability were established after sample extraction. The method provides an efficient and safe quality control tool for determination of TMS in topical creams.

Simultaneous determination of five anthraquinones in a Chinese traditional preparation by RP-HPLC using an improved extraction procedure

2014 ◽  
Vol 12 (5) ◽  
pp. 455-462 ◽  
Author(s):  
Yan-bin Shi ◽  
Hui-li Li ◽  
Hai-qin Wang ◽  
Yan-biao Yang ◽  
Xiao-yun Zhang ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Extraction Procedure ◽  
Rp Hplc ◽  
Traditional Preparation
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