Field method for the determination of aromatic primary amines in air. Part II. Development of a sensitive field test

The Analyst ◽  
1981 ◽  
Vol 106 (1267) ◽  
pp. 1088 ◽  
Author(s):  
D. W. Meddle ◽  
A. F. Smith
2021 ◽  
pp. 027112142098171
Author(s):  
Michael D. Toland ◽  
Jennifer Grisham ◽  
Misti Waddell ◽  
Rebecca Crawford ◽  
David M. Dueber

Rasch and classification analyses on a field-test version of the Assessment, Evaluation, and Programming System Test—Third Edition (AEPS-3), a curriculum-based assessment used to assess young children birth to age 6 years, were conducted. First, an evaluation of the psychometric properties of data from each developmental area of an AEPS-3 field-test version was conducted. Next, cutoff scores at 6-month age intervals were created and then the validity of the cutoff scores was evaluated. Results using Rasch modeling indicated acceptable model fit statistics with reasonable reliability estimates within each developmental area. Classification results showed cutoff scores accurately classified a high percentage of eligible children. Findings suggest that scores from a field-test version of the AEPS-3 are reliable within developmental areas. To the extent allowed by state criteria, early childhood interventionists could possibly use a new field-test version of the AEPS-3 to determine or corroborate eligibility for special education services.


1993 ◽  
Vol 48 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Joseph Grobe ◽  
Duc Le Van ◽  
Gudrun Lange

The course of the reactions o f fluorophosphaalkenes F3CP = C (F)OR [R = Me (1), Et (2)] with methanol or ethanol strongly depends on the experimental conditions. Thus at 70 °C a mixture of the 2-phosphapropionic acid ester F3CP (H )CO2R [R = Me (3), Et (4)] and trifluoromethylphosphane H2PCF3 is formed [molar ratio: 3 or 4 /H2 CF3 ≈1/1]. If the precursors F3CP (H )CO2R [R = Me (3), Et) are used as starting materials, the reaction with ROH under the same conditions affords 3 and 4, respectively, (90 to 95% yield) with only traces of H2PCF 3. In the presence o f iPr2NH these precursors react with R′OH to give the novel trifluoromethylphosphaalkenes F3CP = C (OR )OR [R /R′: Me/Me (6); E t/E t (7); Me/Et (8)]. With Et2NH , 3 undergoes an addition/elimination process yielding the interesting push/pull system Et2N(F)C = P-CO2Me (5). 1 and 2 react with primary amines R′NH2 (R′= tBu, Me) with stereoselective formation of the fairly labile phosphaalkenes F3CP = C(OR)NHR′ [R /R′: Me/tBu (9), Et/tBu(10), Me/Me (11)] with trans-positions for CF3 and NHR′.The new compounds 3 -11 were characterized by spectroscopic investigations (1H , 19F, 31P, 13C NMR ; IR, MS) and determination of M+ or typical fragment ions [M+ -OR ] by high resolution mass spectrometry.


Soil Research ◽  
1989 ◽  
Vol 27 (4) ◽  
pp. 663 ◽  
Author(s):  
EA Close ◽  
HKJ Powell

This paper examines the use of short extraction times, and the determination of aluminium with chrome azurol S (CAS), for the estimation of 0.02 M CaCl2-soluble aluminium in soils. It reports the correlation between CAS-reactive aluminium in 5 min extracts and percent maximum yield of white clover (Trifolium repens) for a series of acid soils. The reactivity of soluble and colloidal aluminium species with the metallochromic reagent CAS has been assessed. ~ l ( a q ) ~ + , simple hydroxy species and complexes of weakly binding ligands (salicylic acid, tannins) are CAS-reactive (2 rnin). In contrast, complexes of strongly binding ligands (citric acid, fulvic acid) are not CAS-reactive ([Al] ~ [L] ~ [CAS] ~ 1-2~10-5 M). For a series of six limed phosphated topsoils and subsoils (pH 4.2-5.5), 0.02 M CaCl2- soluble aluminium, as determined with CAS, was negatively correlated against the percent maximum yield of white clover; r2 = -0.73** (5 min extraction), n = 20. This correlation is similar to that for yield against total aluminium as determined by atomic absorption spectroscopy after 60 min extraction (r2 = -0.77**). However, the colorimetric analysis is more convenient and sensitive; further, it does not measure colloidal and polymeric aluminium species (which may not be plant-available). The satisfactory correlation achieved for short extraction times suggests use of CAS for a rapid field method for aluminium toxicity in soils.


2021 ◽  
pp. 109798
Author(s):  
Amalia D. Kalampaliki ◽  
Steve Vincent ◽  
Suman Mallick ◽  
Hoang-Ngoan Le ◽  
Guillaume Barnoin ◽  
...  

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