Residue analysis of onions and other foodstuffs with a complex matrix using two-dimensional capillary-GC with three selective detectors

1991 ◽  
Vol 339 (6) ◽  
pp. 395-398 ◽  
Author(s):  
H.-J. Stan ◽  
B. Christall
Keyword(s):  
Residue Analysis ◽  
Two Dimensional ◽  
Complex Matrix ◽  
Capillary Gc ◽  
Selective Detectors

Two-dimensional MoS2 nanosheets as a capillary GC stationary phase for highly effective molecular screening

The Analyst ◽  
2014 ◽  
Vol 139 (14) ◽  
pp. 3533 ◽  
Author(s):  
Jia Jia ◽  
Fujian Xu ◽  
Shanling Wang ◽  
Xue Jiang ◽  
Zhou Long ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Two Dimensional ◽  
Molecular Screening ◽  
Mos2 Nanosheets ◽  
Capillary Gc ◽  
Highly Effective

scholarly journals Coding of Luminance and Color Differences on Neurons in the Rabbit's Visual System

2008 ◽  
Vol 11 (2) ◽  
pp. 349-362 ◽  
Author(s):  
Dmitry V. Evtikhin ◽  
Vladimir B. Polianskii ◽  
Dzekshen E. Alymkulov ◽  
Evgenii N. Sokolov†
Keyword(s):  
Factor Analysis ◽  
Visual System ◽  
Lateral Geniculate Nucleus ◽  
Sensory Information ◽  
Two Dimensional ◽  
Tonic Component ◽  
Vector Coding ◽  
Lateral Geniculate ◽  
Color Differences ◽  
Selective Detectors

The neuronal activity in the rabbit's visual cortex, lateral geniculate nucleus and superior colliculus was investigated in responses to 8 color stimuli changes in pairs. This activity consisted of phasic responses (50-90 and 130-300 Ms after stimuli changes) and tonic response (after 300 Ms). The phasic responses used as a basis for the matrices (8 × 8) constructed for each neuron included the average of spikes/sec in responses to all stimuli changes. All matrices were treated by factor analysis and the basic axes of sensory spaces were revealed. Sensory spaces reconstructed from neuronal spike discharges had a two-dimensional (with brightness and darkness axes) or four-dimensional (with two color and two achromatic axes) structure. Thus it allowed us to split neurons into groups measuring only brightness differences and the measuring of color and brightness differences between stimuli. The tonic component of most of the neurons in the lateral geniculate nucleus showed linear correlation with changes in intensities; therefore, these neurons could be characterized as pre-detectors for cortical selective detectors. The neuronal spaces demonstrated a coincidence with spaces revealed by other methods. This fact may reflect the general principle of vector coding (Sokolov, 2000) of sensory information in the visual system.

scholarly journals Multiresidue Analysis of Pesticides in Fresh Fruits and Vegetables Using Procedures Developed by the Florida Department of Agriculture and Consumer Services

1999 ◽  
Vol 82 (6) ◽  
pp. 1419-1435 ◽  
Author(s):  
Joanne Cook ◽  
Mary Pat Beckett ◽  
Brian Reliford ◽  
Walter Hammock ◽  
Marc Engel
Keyword(s):  
Fruits And Vegetables ◽  
Methylene Chloride ◽  
Solid Phase ◽  
Residue Analysis ◽  
Department Of Agriculture ◽  
Multiresidue Analysis ◽  
California Department ◽  
Florida Department ◽  
Consumer Services ◽  
Selective Detectors

Abstract Improved quality and efficiency of pesticide residue analysis were achieved by examining all aspects of the laboratory process. In an effort to eliminate methylene chloride hazardous waste, an acetonitrile extraction method, originally developed by the California Department of Agriculture, was modified and adopted. Sample size and solvent consumption were reduced with the new method. Custom glassware racks and disposable supplies reduced overall analysis time. Gravity-fed, solid-phase extraction simplified sample preparation and provided cleaner extracts for gas chromatographic analyses. Modifications to the method were made to achieve the ruggedness needed to maintain quality objectives during routine analysis. Instrumental improvements, including new selective detectors, retention time locking, and mass spectrometry screening for all samples, provided the laboratory with efficient, reliable, and confirmed analytical results.

scholarly journals Multi-residue analysis of polar pesticides in surface water and sediment by high performance liquid chromatography

2015 ◽  
Vol 18 (2) ◽  
pp. 159-165
Author(s):  
Hai Lam Son Truong ◽  
Trang Thi Thuy Nguyen ◽  
Huyen Ngoc Tran ◽  
Trang Thi Nhu Tran
Keyword(s):  
Surface Water ◽  
High Performance ◽  
Solid Phase ◽  
Residue Analysis ◽  
Complex Matrix ◽  
Quechers Method ◽  
Sediment Samples ◽  
Polar Pesticides ◽  
Water And Sediment ◽  
Cleanup Procedure

We have successfully studied the analytical method of polar pesticides like carbofuran, pirimicarb, thiodicarb, atrazine, simazine, carbaryl, diuron, isoprocarb in surface water and sediment by HPLC-UV. The method could be applied to HPLC- MS. The stable recoveries ranged from 79 – 110 % with surface water and sediment samples. Especially, a cleanup procedure combined QuEChERS method and solid phase extraction has been developed to analyse these compounds in sediment, a very complex matrix.

Gas Chromatography for Pesticide Residue Analysis; Some Practical Aspects

1965 ◽  
Vol 48 (5) ◽  
pp. 1037-1058
Author(s):  
Jerry A Burke
Keyword(s):  
Gas Chromatography ◽  
Pesticide Residue ◽  
Pesticide Residues ◽  
Residue Analysis ◽  
Organophosphorus Pesticide ◽  
Qualitative And Quantitative Analysis ◽  
Residue Determination ◽  
Accuracy And Precision ◽  
Multiple Detection ◽  
Selective Detectors

Abstract The operations necessary for the application of gas chromatography to multiple detection of pesticide residues are described and discussed. Gas chromatography with specific or selective detectors provides qualitative and quantitative analysis of a number of pesticide residues present simultaneously in a single sample. Gas chromatography has been applied successfully to chlorinated pesticide residues; it shows promise as an analytical tool for organophosphorus pesticide residue determination. When the gas chromatography system is operating efficiently, accuracy and precision are good at the nanogram to microgram level. Rules are given to achieve reliable results by gas chromatography.

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