Collaborative Study of the Comparison of Mineral Wool Insulations in the Forensic Laboratory

1977 ◽  
Vol 60 (4) ◽  
pp. 772-777
Author(s):  
Elmer T Miller
Keyword(s):  
Hydrochloric Acid ◽  
Collaborative Study ◽  
Mineral Wool ◽  
Small Samples ◽  
Matched Pairs ◽  
Microscopic Appearance ◽  
Large Samples ◽  
Heat Treated

Abstract A method for the comparison of mineral wool insulation specimens was studied collaboratively. Exemplar and questioned specimens are compared microscopically for color of resin, shapes and quantity of slugs or shot, relative fiber diameters, and other gross characteristics. Then the resin is burned off, and the fibers are annealed at 500°C. The heat-treated fibers are compared for shortwave ultraviolet fluorescence, microscopic appearance, solubility in dilute and concentrated hydrochloric acid, and refraction and dispcrsion indices according to 45.002–5.007. Eight collaborators in 6 laboratories compared 8 matched pairs of large samples (such as exemplars) and small samples (such as might be found on a suspect’s clothing).

Comparison of Mineral Wool Insulations in the Forensic Laboratory: Second Collaborative Study

1979 ◽  
Vol 62 (4) ◽  
pp. 792-798
Author(s):  
Elmer T Miller
Keyword(s):  
Collaborative Study ◽  
Mineral Wool ◽  
Common Origin ◽  
The Other ◽  
Microscopic Appearance ◽  
Different Origin

Abstract A method for comparing mineral wool insulationswas collaboratively studied a second time.Specimens are examined microscopically forcolor, disposition of resin, fiber diameters,quantity of slugs, and other gross microscopiccharacteristics. The resin is burned off and thefibers are annealed at 500°C. The heat-cleanedfibers are examined for shortwave ultravioletfluorescence, microscopic appearance, solubilityin HCI, and indices of refraction according to45.002-45.007. Ten collaborators examined 9specimens of mineral wool, 4 of which werefrom one large lot of Owens-Corning Fiberglasand 2 of which were from a single Johns-Manville ceiling tile. The other 3 were fromdifferent sources. Eight collaborators correctlyconcluded that the Owens-Corning samplescould have had a common origin, that theJohns-Manville samples could have had a commonorigin, and that the others were of independentlydifferent origins. Two collaboratorsin the same laboratory, using other than therecommended equipment, concluded that theOwens-Corning samples were one class, that theJohns-Manville samples were one class, andthat the others were of different origin, but theyfound slight differences in the refractive indicesof the Johns-Manville samples and did not concludecommon origin for them. The method hasbeen adopted as interim official first action.

scholarly journals Statistics for N = 1

2020 ◽  
Vol 30 (1) ◽  
pp. e38066
Author(s):  
Jimmie Leppink
Keyword(s):  
Statistical Approach ◽  
Small Samples ◽  
Outcome Variable ◽  
Interval Estimates ◽  
Linear Relations ◽  
Large Samples ◽  
Different Types ◽  
Research In Education ◽  
Study Designs ◽  
Larger Sample

Research in education is often associated with comparing group averages and linear relations in sufficiently large samples and evidence-based practice is about using the outcomes of that research in the practice of education. However, there are questions that are important for the practice of education that cannot really be addressed by comparisons of group averages and linear relations, no matter how large the samples. Besides, different types of constraints including logistic, financial, and ethical ones may make larger-sample research unfeasible or at least questionable. What has remained less known in many fields is that there are study designs and statistical methods for research involving small samples or even individuals that allow us to address questions of importance for the practice of education. This article discusses one type of such situations and provides a simple coherent statistical approach that provides point and interval estimates of differences of interest regardless of the type of the outcome variable and that is of use in other types of studies involving large samples, small samples, and single individuals.

Collaborative Study of an Automated Method for Phosphorus in Fertilizers

1972 ◽  
Vol 55 (5) ◽  
pp. 979-983
Author(s):  
Frank J Johnson
Keyword(s):  
Collaborative Study ◽  
Available Phosphorus ◽  
Official Method ◽  
Matched Pairs ◽  
F Test ◽  
Automated Method

Abstract A collaborative study was made of an automated method for total and direct available phosphorus (P2O5) in comparison with the official gravimetric quimociac method, 2.023–2.025. Eight laboratories participated in the analysis of the 13 sample solutions, and the results were evaluated by the technique of closely matched pairs. The fc-test showed no difference in the means of the results of the 2 methods. The estimates of the random, systematic, and total errors of the automated method all differed significantly from those of the official method when evaluated by the F-test. Further study of the automated method for P2O5 in fertilizers is recommended.

Liquid Chromatographic Determination of Carbofuran in Technical and Formulated Products: Collaborative Study

1986 ◽  
Vol 69 (5) ◽  
pp. 915-918
Author(s):  
Edward J Kikta ◽  
◽  
E Bane ◽  
A Burns ◽  
A Christensen ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Data Sets ◽  
Matched Pairs ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method for the analysis of technical and formulated carbofuran samples was evaluated in a collaborative study. Carbofuran is determined by reverse phase LC, using a water-methanol mobile phase and acetophenone as internal standard, and detected at 280 nm. Twelve samples, 5 formulations and technical matched pairs, were analyzed by 17 collaborating laboratories. Accuracy and variability of results are typical of large LC data sets. The method has been adopted official first action.

Gas-Liquid Chromatographic Method for Analysis of Pentachloronitrobenzene Formulations: Collaborative Study

1982 ◽  
Vol 65 (1) ◽  
pp. 110-114
Author(s):  
Alan R Hanks
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Matched Pairs ◽  
Commercial Products ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Wettable Powder ◽  
Liquid Chromatographic

Abstract A collaborative study has been conducted on a gasliquid chromatographic (GLC) method for determining pentachloronitrobenzene (PCNB) in formulations. Wettable powder, liquid, and granular matched pairs of commercial products were analyzed by 17 laboratories using peak height measurements and by 12 laboratories using integrator area measurements. Samples were dissolved in chloroform and aliquots were mixed with internal standard before GLC analysis on a 5% SE-30 column. Mean coefficients of variation for the completed study were 1.54% for integrator area measurements and 1.35% for peak height measurements. The method has been adopted official first action.

Collaborative Study of the Automated Method for K2O in Fertilizers

1971 ◽  
Vol 54 (3) ◽  
pp. 646-650
Author(s):  
Larry G Hambleton
Keyword(s):  
Primary Standard ◽  
Collaborative Study ◽  
Potassium Nitrate ◽  
Matched Pairs ◽  
Automated Method ◽  
Standard Deviations ◽  
Complete Sets

Abstract The automated method for K2O in fertilizers was studied again this year. The results from the automated method are compared to those obtained by the official STPB method, 2.090, for 10 typical fertilizer samples and a potassium nitrate primary standard. Nine complete sets of data are evaluated by the technique of closely matched pairs. The data show no difference between the different models of flame photometers. The means and standard deviations from the automated method compare favorably to those received with the official STPB method. The automated method for K2O in fertilizers has been adopted official first action.

Automated Determination of Phosphorus in Fertilizers Collaborative Study

1978 ◽  
Vol 61 (3) ◽  
pp. 533-536
Author(s):  
Frank J Johnson
Keyword(s):  
Collaborative Study ◽  
Available Phosphorus ◽  
Matched Pairs ◽  
Automated Method ◽  
Complete Sets ◽  
Automated Determination

Abstract An automated method for determining total and direct available P2O5 in fertilizers was compared to the official final action gravimetric quinolinium molybdophosphate and spectrophotometric molybdovanadate methods in a collaborative study. Ten samples were sent to 10 collaborators for analysis. Eight complete sets of data were returned, and the ninth collaborator returned data for direct available phosphorus by the automated method only. The data were statistically analyzed by the technique of closely matched pairs. No significant overall difference was found between methods or among collaborators. The automated method has been adopted as official first action for phosphorus.

Comparison of AOAC and Atomic Absorption Spectrophotometry Methods for Determining Sodium in Fertilizers: Collaborative Study

1983 ◽  
Vol 66 (5) ◽  
pp. 1234-1241
Author(s):  
Luis F Corominas ◽  
Roberto A Navarro ◽  
Pedro Rojas ◽  
◽  
M Aihara ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Sodium Content ◽  
Matched Pairs ◽  
High Potassium ◽  
Absorption Spectrophotometry ◽  
Low Sodium ◽  
Aoac Method ◽  
Aas Method

Abstract A collaborative study was carried out to compare AOAC method 2.147-2.150 for determining sodium in fertilizers with the atomic absorption spectrophotometric (AAS) method. Twelve synthetic NPK samples, 6 pairs of blind duplicates (0.06-8.5% Na), were sent to 22 collaborators; a total of 13 sets of results were received and evaluated by the modified matched pairs technique. The AAS method showed better performance in samples with low sodium content and high potassium content. The AAS method has been adopted official first action for determining sodium in fertilizers.

scholarly journals Determination of Volatile Bases in Seafood Using the Ammonia Ion Selective Electrode: Collaborative Study

2000 ◽  
Vol 83 (4) ◽  
pp. 933-943 ◽  
Author(s):  
P Christopher Ellis ◽  
Lori F Pivarnik ◽  
Mamadou Thiam ◽  
L Berger ◽  
S Field ◽  
...  
Keyword(s):  
Ammonium Chloride ◽  
Atlantic Cod ◽  
Collaborative Study ◽  
Ion Selective Electrode ◽  
Atlantic Halibut ◽  
Matched Pairs ◽  
Selective Electrode ◽  
Atlantic Mackerel ◽  
Standard Deviations

Abstract Nine collaborating laboratories tested a combination of 23 seafood samples for volatile bases using an ammonia ion selective electrode. Results were reported as mg NH3/100 g fish, but the method reflected levels of both ammonia and trimethylamine, which permeated the ammonia membrane. The 23 samples were broken down into 8 blind duplicate pairs, 2 Youden matched pairs, and 3 single samples covering fresh to spoiled product ranging from 8 to 82 mg NH3/100 g. Seven species were evaluated: Atlantic cod, squid, Atlantic halibut, gray sole, monkfish, dogfish, and Atlantic mackerel. The ammonia electrode assay was performed on an aqueous homogenate consisting of 95 mL distilled water and 5.0 g sample tissue. Alkaline ion strength adjusting solution (2 mL) was added to the homogenate to liberate ammonia that was sensed by the ion specific electrode and measured on a precalibrated portable meter. Repeatability standard deviations (RSDr) ranged from 4.2 to 17%; reproducibility standard deviations (RSDR) ranged from 8.8 to 21%. A standard ammonium chloride solution was provided to all laboratories to spike 3 different samples at 10 mg NH3/100 g. Recoveries of added ammonia as ammonium chloride for fresh, borderline, and spoiled samples were 88.6, 107, and 128%, respectively.

Collaborative Study of an Ion Exchange Method for Ephedrine in Ephedrine Sulfate Sirup NF

1969 ◽  
Vol 52 (4) ◽  
pp. 854-857
Author(s):  
Donald J Smith
Keyword(s):  
Hydrochloric Acid ◽  
Ion Exchange ◽  
Positive Charge ◽  
Exchange Resin ◽  
Collaborative Study ◽  
Cation Exchange Resin ◽  
Polystyrene Sulfonate ◽  
Resin Column ◽  
Exchange Method ◽  
Ion Exchange Method

Abstract An ion exchange procedure for Ephedrine Sulfate Sirup NF, based on the ability of ephedrine to be retained on a polystyrene sulfonate cation exchange resin column, was studied collaboratively by eight laboratories. The compound is held on the column by a positive charge located in the cationic center of the molecule, it is then eluted with hydrochloric acid, and its ultraviolet absorption is measured. The addition of 57.88 mg ephedrine sulfate to Ephedrine Sulfate Sirup NF resulted in recoveries of 58.39 and 57.72 mg, or 101 and 100%, respectively. Recoveries for collaborative samples, each containing 19.22 and 19.33 mg/5 ml, were 99.8 ± 1.83 and 101 ± 4.09%, respectively.

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