A Gas Chromatographic Column for Pesticide Residue Analysis: Retention Times and Response Data

1966 ◽  
Vol 49 (2) ◽  
pp. 374-385
Author(s):  
Jerry A Burke ◽  
Wendell Holswade
Keyword(s):  
Liquid Phase ◽  
Flow Rate ◽  
Residue Analysis ◽  
Operating Conditions ◽  
The Other ◽  
Pesticide Residue Analysis ◽  
Column Temperature ◽  
Response Data ◽  
Relative Retention ◽  
Injection Temperature

Abstract DC-200 and QF-1 have been combined as the liquid phase in a GLC column to give a different elution of pesticides from the nonpolar methyl silicones now in wide use. The column packing consists of intimately mixed, equal portions of previously coated 80/100 mesh Gas Chrom Q: one portion with 15% QF-1 and the other with 10% DC-200. Operating conditions for a 6 ft × 4 mm i.d. column are as follows: column temperature, 200°C; injection temperature, 225°C; and flow rate, 120 ml N2/min. Relative retention times and response data for electron capture and microcoulometric GLC systems are tabulated for over 85 pesticide chemicals.

Gas Chromatography with Microcoulometric Detection for Pesticide Residue Analysis

1964 ◽  
Vol 47 (5) ◽  
pp. 845-859
Author(s):  
Jerry Burke ◽  
Wendell Holswade
Keyword(s):  
Detection System ◽  
Residue Analysis ◽  
Detection Technique ◽  
General Level ◽  
Chlorinated Pesticides ◽  
Efficient Operation ◽  
Column Temperature ◽  
Relative Retention ◽  
Minimum Number ◽  
Multiple Detection

Abstract Conditions are given for the most efficient operation of the microcoulometric gas chromatograph as a multiple detection technique for residues of chlorinated pesticides. Conditions are as follows: Column, aluminum, 6’ long by 4.5 mm i.d., packed with 10% DC 200 silicone fluid (12,500 est) on 80/90 mesh Anakrom ABS (conditioned 1—5 days at 250°C), 210°C column temperature, and 120 ml/min. N2 flow. Chromatography of certain pesticides is improved by injection of cleaned up crop extracts. Columns with a minimum number of bends are superior to coiled columns. Chromatography is not improved by using glass columns. Relative retention times and instrument sensitivity are tabulated for 87 chlorinated and 26 thio pesticide chemicals. Theoretical chloride recoveries are given for 14 compounds and sulfur recoveries for 3 compounds. Theoretical recoveries indicate that the MCGC system is linear for a particular pesticide when it is present above some minimum quantity. Sample cleanup is essential for consistently accurate and reproducible results. The general level of "maximum sensitivity" of this multiple detection technique is approximately 0.01 ppm. The specificity of the detection system (for CI-, Br-, I- or sulfur) is the instrument's greatest virtue.

scholarly journals CO₂ STRIPPING FROM DIETHANOLAMINE USING MEMBRANE CONTACTORS: MODEL VALIDATION AND MEMBRANE WETTABILITY

2019 ◽  
Vol 81 (6) ◽  
Author(s):  
H. N. Mohammed ◽  
Omar S. Lateef ◽  
Ghassan H. Abdullah ◽  
A. L. Ahmad
Keyword(s):  
Liquid Phase ◽  
Flow Rate ◽  
Polyvinylidene Fluoride ◽  
Gas Flow ◽  
Hollow Fiber Membrane ◽  
Operating Conditions ◽  
Co Stripping ◽  
Sweeping Gas ◽  
Membrane Contactors ◽  
The Impact

In the present work, CO2 desorption (stripping) from diethanolamine (DEA) solution using polyvinylidene fluoride hollow fiber membrane contactor is theoretically investigated. A comprehensive two dimensional mathematical model is developed to evaluate the membrane wettability when DEA solution is used at different operating conditions such as sweeping gas flow rate, initial CO2 loading and liquid phase temperature. In addition, the impact of flow rate of liquid phase on the CO2 stripping performance was theoretically investigated. The simulated results were compared with the experimental data obtained from literature. The results revealed that the PVDF membrane was suffered from wetting at studied operating conditions.

Retention Time Data for Organochlorine, Organophosphorus, and Organonitrogen Pesticides on SE-30 Capillary Column and Application of Capillary Gas Chromatography to Pesticide Residue Analysis

1983 ◽  
Vol 66 (5) ◽  
pp. 1084-1095
Author(s):  
Brian D Ripley ◽  
Heinz E Braun
Keyword(s):  
Pesticide Residue ◽  
Retention Time ◽  
Relative Retention Time ◽  
Residue Analysis ◽  
Pesticide Residue Analysis ◽  
Time Data ◽  
Relative Retention ◽  
Single Temperature ◽  
Organonitrogen Pesticides ◽  
Temperature Programmed

Abstract Relative retention time data for 194 pesticides and metabolites are reported for a 15 m SE-30 capillary gas chromatographic column under a single temperature programmed regime. The reproducibility of retention time and quantitation is discussed and the performance of electron capture and nitrogenphosphorus thermionic detectors is evaluated in relation to pesticide residue analysis.

Alkaline Pre-Column for Use in Gas Chromatographic Pesticide Residue Analysis

1969 ◽  
Vol 52 (3) ◽  
pp. 548-553
Author(s):  
George A Miller ◽  
Clyde E Wells
Keyword(s):  
Pesticide Residues ◽  
Chromatographic Analysis ◽  
Relative Retention Time ◽  
Residue Analysis ◽  
Pesticide Residue Analysis ◽  
Time Data ◽  
Additional Information ◽  
Relative Retention ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Abstract An alkaline pre-column is described for use with gas-liquid chromatographic analysis of pesticide residues. The alkaline layer is contained in one side of a column with dual injection ports so that it can be used when additional information is needed for better chromatogram interpretation. The alkaline pre-column destroys some pesticides, changes the retention times of others, and leaves some unaltered. Many troublesome crop peaks are eliminated, thereby permitting quantitation and/or identification of many pesticide residues. Physical column characteristics are described and relative retention time data are reported for 32 commonly found pesticides.

Determination of Paeoniflorin and Paeonol in Houyinan Tablet by UPLC

2012 ◽  
Vol 581-582 ◽  
pp. 68-72
Author(s):  
Chu Qin Yu ◽  
Hua Qing Lin ◽  
Yue Han Hou ◽  
Zhong Feng Shi ◽  
Di Shi Lin
Keyword(s):  
Quality Control ◽  
Simultaneous Determination ◽  
Flow Rate ◽  
Mobile Phase ◽  
Gradient Elution ◽  
The Other ◽  
Column Temperature ◽  
Average Recovery ◽  
Injection Volume

In this study, our purpose was to establish a UPLC method for the simultaneous determination of Paeoniflorin and Paeonol in Houyinan Tablet. The separation was performed on Acquity BEH C18 column(2.1mm×100mm,1.7μm), the mobile phase was acetonitrile-water with gradient elution at a flow rate of 0.2 mL•min-1, the detection wavelength was 230nm, the column temperature was 30°Cand the injection volume was 2μL. Paeoniflorin and Paeonol reached effective separation with the other components in this chromatographic conditions. Paeoniflorin and Paeonol were linear within the range of 0.0406~0.4064μg(r=0.9999) and 0.0426~0.4256μg (r=0.9999), respectively. The average recovery was 99.82% and 100.6%. The results of method validation indicated that the method was simple,quick,accurate, specific and less solvent consumption. It can be used for the quality control of Houyinan Tablet.

scholarly journals Desorption of Vitamin E from Silica-Packed Fixed-Bed Column by Isopropanol

2010 ◽  
Vol 6 (5) ◽  
Author(s):  
Boon-Seang Chu ◽  
Siew-Young Quek ◽  
Badlishah Sham Baharin ◽  
Yaakob Bin Che Man
Keyword(s):  
Vitamin E ◽  
Flow Rate ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Desorption Rate ◽  
Fixed Bed Column ◽  
Desorption Process ◽  
Column Temperature ◽  
Percentage Recovery ◽  
Bed Height

Desorption of vitamin E from silica-packed fixed-bed column was studied as functions of column bed height, column temperature and flow rate of isopropanol. Isopropanol was the desorbing solvent and it was eluted through the columns saturated with vitamin E. The desorption profiles of all systems showed that vitamin E might desorb at two distinct rates simultaneously. The slow desorbing step was the rate-controlling process for recovery of vitamin E. The desorption rate increased with the decrease of column bed height and flow rate, but increased with increasing column temperature. This indicated that the desorption process was an endothermic process. The percentage recovery of vitamin E upon completion of desorption was considered high for all systems, ranging from 94.8 to 98.8%, with vitamin E concentration in the extract of 18.5-21.5%. Although the bed height, column temperature and flow rate were functions of desorption rate, it appeared that percentage recovery and vitamin E concentration in the extract were rather unaffected by the operating conditions tested if the column was eluted by isopropanol for a sufficient time to desorb vitamin E. Nevertheless, the use of isopropanol would be more efficient if desorption was carried out at lower flow rate and higher column temperature.

General Method for Determination of Pesticide Residues in Samples of Plant Origin, Soil, and Water. III. Gas Chromatographic Analysis and Confirmation

1981 ◽  
Vol 64 (3) ◽  
pp. 749-768
Author(s):  
Árpád Ambrus ◽  
Éva Visi ◽  
Ferenc Zakar ◽  
Éva Hargitai ◽  
László Szabó ◽  
...  
Keyword(s):  
Chromatographic Analysis ◽  
Residue Analysis ◽  
Gas Liquid Chromatography ◽  
Pesticide Residue Analysis ◽  
Temperature Programming ◽  
Plant Origin ◽  
Relative Retention ◽  
Soil And Water ◽  
General Method

Abstract Gas-liquid chromatography is widely used in pesticide residue analysis, and numerous packings of various polarity are recommended. We selected OV-22, OV-101, NPGS, SE-30 (3% on Gas-Chrom Q), and 1.95% SP-2401/1.5% SP-2250 on Supelcoport as basic packings. Relative retention times for aldrin and parathion-methyl were determined at 140,160, 180, or 200°C and during temperature programming. OV-22 and OV-101 were most suitable for general purposes. A study on the performance of thermionic delectors suggested that their performance can be characterized and should be regularly controlled with test substances containing different hetero elements. Columns as short as 45-90 cm were suitable for screening purposes, and their advantages over traditional long columns are demonstrated. The fractionation of pesticides in an extract on silica gel columns was effective and practical for the confirmation of pesticides.

Efficiency Parameters of Gas Chromatography Columns Used in Pesticide Residue Analysis

1968 ◽  
Vol 51 (1) ◽  
pp. 34-39
Author(s):  
David C Bostwick ◽  
Laura Giuffrida
Keyword(s):  
Gas Chromatography ◽  
Liquid Phase ◽  
Residue Analysis ◽  
Mesh Size ◽  
Solid Support ◽  
Pesticide Residue Analysis ◽  
Column Length ◽  
Experimental Conditions ◽  
Chromatography Columns ◽  
Gas Chromatography Columns

Abstract The parameters in the preparation and operation of columns used in the gas chromatography of pesticide residues were studied and effects of varying each were compared. The parameters investigated were column length, diameter, configuration, amount of liquid phase, and solid support mesh size. Experimental conditions have been determined for more efficient columns, as follows: 4—10% liquid phase, 4 mm i.d column, length not less than 6 feet, 100—120 mesh for 6 foot column, 80—100 mesh for 6—12 foot columns

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