QUALITATIVE CONFIRMATION AND THE RAVENS PARADOX

2005 ◽  
pp. 87-127
Keyword(s):  
Qualitative Confirmation

GC/MIP/AED Method for Pesticide Residue Determination in Fruits and Vegetables

1991 ◽  
Vol 74 (6) ◽  
pp. 991-998 ◽  
Author(s):  
Keh-Chuh Ting ◽  
Peng Kho
Keyword(s):  
Pesticide Residue ◽  
Fruits And Vegetables ◽  
Residue Analysis ◽  
Atomic Emission ◽  
Pesticide Residue Analysis ◽  
Organophosphate Pesticide ◽  
Microwave Induced Plasma ◽  
Organochlorinated Pesticides ◽  
Instrument Response ◽  
Qualitative Confirmation

Abstract This research describes the results of a gas chromatography/microwave induced plasma/atomic emission detection (GC/MIP/AED) method performed on a Hewlett-Packard 5921A system for pesticide residue analysis in fruits and vegetables. Atotal of 6 experiments were conducted: (1) sensitivity and linearity studies for elements S, P, CI, and N by analyzing dursban; (2) a study of instrument response to CI concentration in pesticide molecules; (3) organochlorinated pesticide recoveries; (4) organophosphate pesticide recoveries; (5) carbamate pesticide recoveries; and (6) investigation of metallic pesticides with pllctran and vendex as standards. The rank according to sensitivity and linearity was found to be as follows: S-181>P-178>CI-479>N-174. Instrument response to the concentration of chlorine atoms in the pesticide molecule was linear, with a correlation coefficient of 0.89. Recoveries of organochlorinated pesticides were 91.7-109.3%, with the exception of citrus, whose recovery was affected by coeluting Interferences. Organophosphate recoveries were 73.2% or higher, except for the cygon oxygen analog, which degraded in the GC system under all circumstances. Carbamate recoveries were inconsistent quantitatively; however, the information generated from elements N and S were useful for qualitative confirmation of other methods, such as LC postcolumn derivatization analysis. Overall, the GC/MIP/AED method is powerful for qualitative confirmation in pesticide residue analysis. The instrument’s capability of acquiring multi-elements (CI and P) selectively and accurately is an alternative method for organochlorinated and organophosphate pesticide residue analyses. In addition, the GC/MIP/AED system is easy to use, simple to maintain, and its chromatograms can be interpreted by any chromatography analyst without much prior training.

Methods of Estimating Dietary Exposure of the General Population to Organochlorine Insecticide Residues: Diet Analyses 1965–1967

1972 ◽  
Vol 55 (6) ◽  
pp. 1245-1258
Author(s):  
A E J Mcgill ◽  
J Robinson ◽  
M Stein
Keyword(s):  
General Population ◽  
Dietary Exposure ◽  
Organochlorine Insecticide ◽  
Dietary Intakes ◽  
Insecticide Residues ◽  
Organochlorine Insecticides ◽  
Dietary Surveys ◽  
The Difference ◽  
Qualitative Confirmation ◽  
Diet Analyses

Abstract The amounts of organochlorine insecticides in the diet of the general population of Great Britain has been estimated by analyzing representative whole cooked meals. The methods of quantitation are briefly outlined and techniques suitable for qualitative confirmation of identity of these compounds are discussed. The estimated dietary intakes are compared with the food in other dietary surveys and, in the case of dieldrin, they are also compared with the amounts calculated from the concentrations of this compound in body fat and blood. The dietary intakes of dieldrin in 1965–1966 and 1967 were estimated to be 0.00030 and 0.00020 mg/kg/day, respectively, the difference being statistically significant. The maximum estimated intakes of total equivalent DDT were 0.0011 and 0.0014, respectively.

Sodium Methylate Treatment of Cleaned Up Plant Extracts in Confirmation of Some Pesticide Residues By Gas-Liquid and Thin Layer Chromatography

1968 ◽  
Vol 51 (5) ◽  
pp. 1095-1101
Author(s):  
C E Mendoza ◽  
P J Wales ◽  
H A Mcleod ◽  
W P Mckinley
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Plant Extracts ◽  
Pesticide Residues ◽  
Sodium Methylate ◽  
Heptachlor Epoxide ◽  
Rapid Procedure ◽  
Qualitative Confirmation ◽  
Layer Chromatography

Abstract A rapid procedure that involves GLC-EC and TLC analyses of plant extracts 5 min after treatment with sodium methylate is described for the qualitative confirmation of some pesticide residues. Plant extracts are cleaned up by elution through a carboncellulose column before treatment. The compounds studied were aldrin, captan, carbophenothion, p,p'-DDD, de-hydrochlorinated p,p-DDD, p,p'-DDE, o,p -DDT, p,p -DDT, Diazinon, dieldrin, disulfoton, heptachlor, heptachlor epoxide, malathion, methoxychlor, de-hydrochlorinated methoxychlor, mevinphos, and parathion. The pesticides added to beet, lettuce, pineapple, potato, and wheat eluates were reliably confirmed by GLC-EC or TLC after sodium methylate treatment. The procedure could be used to confirm only some of the pesticides added to extracts of apples, carrots, cauliflower, grapes, and peas because of components in these samples that gave interfering peaks

Investigation on Determination and Confirmation of Dyrene Added to Plant Extracts: GLC and TLC of Dyrene and Products of Its Reaction in Methanolic Sodium Hydroxide

1970 ◽  
Vol 53 (3) ◽  
pp. 509-513
Author(s):  
P J Wales ◽  
C E Mendoza
Keyword(s):  
Thin Layer ◽  
Silver Nitrate ◽  
Sodium Hydroxide ◽  
Enzyme Inhibition ◽  
Electron Capture ◽  
Plant Extracts ◽  
Uv Light ◽  
Parent Compound ◽  
Spray Reagent ◽  
Qualitative Confirmation

Abstract As determined by electron capture GLC, recoveries of Dyrene from strawberries, potatoes, tomatoes, and cucumber samples, using an acetonitrile extraction-hexane partition procedure, were more than 80%. TLC was used for qualitative confirmation. The possible interference in the GLC and TLC analyses from selected pesticides was investigated. Treatment with methanolic sodium hydroxide converted Dyrene to 2 major products with longer GLC retention times and slower TLC migrat i on rates than the parent compound. Dyrene and the products were visualized on thin layer plates by using a silver nitrate spray reagent or by viewing induced fluorescence under UV light. The products were also detected by an enzyme inhibition procedure.

scholarly journals SSR Markers for Analysing South American Nothofagus Species

2004 ◽  
Vol 53 (1-6) ◽  
pp. 240-243 ◽  
Author(s):  
M. M. Azpilicueta ◽  
H. Caron ◽  
C. Bodénès ◽  
L. A. Gallo
Keyword(s):  
Gene Flow ◽  
Genetic Mapping ◽  
Microsatellite Markers ◽  
Ssr Markers ◽  
Natural Populations ◽  
South American ◽  
Sample Sizes ◽  
Polymorphic Ssrs ◽  
The Cross ◽  
Qualitative Confirmation

Summary11 newly discovered microsatellites were used to identify SSR markers for characterising South American Nothofagus species. This was carried out in six species. The sample sizes used were between four and six individuals per species. The cross-genera transferability of 34 Quercus SSRs was also essayed. Out of the 11 new microsatellite markers, three proved to be polymorphic (NnBIO 11, NgBIO 13 and NgBIO 14). The qualitative confirmation of the inheritance of these markers could also be verified. Polymorphism was also observed in five of the cross-genera transferred SSRs (QrBIO7, quru-GA-0A01, quru-GA-0C11, quru-GA-0I01, quru-GA-0M07). The number of alleles per locus found range between 1 and 6 per species. The eight polymorphic SSRs identified in this study will constitute a valuable tool in the gene flow studies that are currently being carried out in natural populations of South American Nothofagus species. The confirmation of crossspecies and cross-genera transferability opens the way for the use of SSRs as bridge markers in genetic mapping.

scholarly journals Justificação, Probabilidade e Independência

2019 ◽  
Vol 23 (2) ◽  
pp. 207-230
Author(s):  
André Neiva ◽  
Tatiane Marks
Keyword(s):  
Epistemic Justification ◽  
Bayesian Framework ◽  
Epistemic Probability ◽  
Underlying Assumption ◽  
Restricted Version ◽  
Evidential Support ◽  
Qualitative Confirmation

Epistemic justification has been widely accepted as both a gradational and relational notion. Given those properties, a natural thought is to take degrees of epistemic justification to be probabilities. In this paper, we present a simple Bayesian framework for justification. In the first part, after putting the model in an evidentialist form, we distinguish different senses of “being evidence for” and “confirming”. Next, we argue that this conception should accommodate the two relevant kinds of qualitative confirmation or evidential support. In the second part of the paper, we discuss the claim that this view is unable to satisfy the modified version of the conjunction closure for beliefs in probabilistically independent propositions. We defend that the underlying assumption on which this objection depends leads to an improper reading of the concept of epistemic probability. After providing a better interpretation of it, we put forward a rationale, which is based on the notion of conditional uncertainty, in support of a more plausible and restricted version of the closure of justification under conjunction.

Thermal Effects in Calendering Viscous Fluids

1951 ◽  
Vol 18 (1) ◽  
pp. 12-18
Author(s):  
M. Finston
Keyword(s):  
Boundary Layer ◽  
Physical Properties ◽  
Thermal Effects ◽  
Thermal Boundary Layer ◽  
Effect Of Temperature ◽  
Thermal Boundary Layer Thickness ◽  
Boundary Layer Effect ◽  
High Speeds ◽  
Layer Effect ◽  
Qualitative Confirmation

Abstract Calendering (rolling) of plastics at high speeds produces blistering and peeling which are attributed to a combination of uneven temperature distribution, and effect of temperature on the physical properties of the material. In this paper the problem is examined by studying the calendering of a viscous liquid in some detail. It is shown that a thermal boundary-layer effect exists of such magnitude as to account for formation of blisters. An example is given using typical calendering dimensions and physical properties of a plastic, which yields a thermal boundary-layer thickness of the order of depth of the blisters as observed. These data furnish further qualitative confirmation to the physical argument.

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