Collaborative Studies on the Salmonella/Microsome Mutagenicity Assay

Abstract Although the Salmonella/plate test has been used extensively, a collaborative study was undertaken to determine the interlaboratory reproducibility of this microbial mutagenicity assay. Four laboratories participating in the study have completed testing, under code, of 61 carcinogens and noncarcinogens. All chemicals were tested both with and without metabolic activation in Salmonella typhimurium strains TA1535, 1537, 1538, 98, and 100. The metabolic activation systems used were derived from the livers of both uninduced and Aroclor 1254-induced Fischer rats, B6C3F1 mice, and Syrian hamsters. Analysis of the results on 23 of the chemicals tested in 3 of the participating laboratories showed that 8 were negative when tested in all laboratories and 13 were positive. Two chemicals gave positive results in 2 laboratories; the same 2 chemicals were negative when tested in the third laboratory.

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Determination of Low-Level Glucose and Fructose in Raw and Refined Crystalline Sugar by High-Performance Anion-Exchange Chromatography: Collaborative Study

Journal of AOAC International ◽

10.1093/jaoac/85.1.95 ◽

2002 ◽

Vol 85 (1) ◽

pp. 95-106 ◽

Cited By ~ 3

Author(s):

Kevin Schäffler ◽

P Bourlet ◽

V Hanko ◽

D Henderson ◽

H Hoebregs ◽

...

Keyword(s):

Anion Exchange ◽

High Performance ◽

Collaborative Study ◽

Anion Exchange Chromatography ◽

Exchange Chromatography ◽

Independent Laboratory ◽

Collaborative Studies ◽

Raw Sugar ◽

Positive Results

Abstract A method was developed and a collaborative study was performed under the auspices of the International Commission of Uniform Methods for Sugar Analysis. The collaborators used high-performance anion-exchange chromatography (HPAEC) to determine trace amounts of glucose and fructose in 3 raw and 3 refined sugar samples provided as blind duplicates. Fourteen laboratories participated in the study. Although difficulties were experienced by a few analysts, 10 laboratories reported positive results. Average repeatabilities and reproducibilities for glucose and fructose in raw sugar were slightly above 5 and 10%, respectively, and the average Horwitz ratios were well under 2. Average repeatabilities and reproducibilities for glucose and fructose in refined sugar were 10 and 22%, respectively; although the Horwitz ratios were >2, they were marginal (2.8). The HPAEC results agreed with results obtained by gas chromatography in an independent laboratory. Because the method was collaboratively studied according to the protocol of the International Union of Pure and Applied Chemistry for collaborative studies, and the results meet its criteria, it is recommended that the method be adopted Official First Action by AOAC INTERNATIONAL.

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Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/73.1.54 ◽

1990 ◽

Vol 73 (1) ◽

pp. 54-57 ◽

Cited By ~ 13

Author(s):

Kurt Kolar

Keyword(s):

Collaborative Study ◽

Colorimetric Method ◽

Meat Products ◽

Acid Oxidation ◽

Colorimetric Determination ◽

Mean Values ◽

Collaborative Studies ◽

Freeze Dried ◽

Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

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Collaborative Studies of Methods for Butterfat in omogenized and Chocolate Milk

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/47.3.573 ◽

1964 ◽

Vol 47 (3) ◽

pp. 573-576

Author(s):

D J Mitchell

Keyword(s):

Collaborative Study ◽

Chocolate Milk ◽

Collaborative Studies

Abstract The AOAC Roese-Gottlieb and Rapid Detergent (TeSa) methods for the determination of butterfat in pasteurized, homogenized milk and in chocolate milk were compared in a collaborative study. The results by the detergent method on both products were comparable to those by the Roese-Gottlieb method. The Babcock method gave low results on the homogenized milk.

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Toxicity and Carcinogenicity of Δ9-Tetrahydrocannabinol in Fischer Rats and B6C3F1 Mice

Toxicological Sciences ◽

10.1093/toxsci/30.1.109 ◽

1996 ◽

Vol 30 (1) ◽

pp. 109-117 ◽

Cited By ~ 2

Author(s):

P. C. CHAN ◽

R. C. SILLS ◽

A. G. BRAUN ◽

J. K. HASEMAN ◽

J. R. BUCHER

Keyword(s):

B6c3f1 Mice ◽

Fischer Rats

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Determination of mono- and diacylglycerols in edible oils and fats by high performance liquid chromatography and evaporative light scattering detector: Results of collaborative studies and the standardised method

Pure and Applied Chemistry ◽

10.1351/pac199971101983 ◽

1999 ◽

Vol 71 (10) ◽

pp. 1983-1991 ◽

Cited By ~ 26

Author(s):

D. Berner ◽

A. Dieffenbacher

Keyword(s):

Liquid Chromatography ◽

Light Scattering ◽

High Performance ◽

Edible Oils ◽

Collaborative Study ◽

Evaporative Light Scattering Detector ◽

Light Scattering Detection ◽

Collaborative Studies ◽

Evaporative Light Scattering

The development, by collaborative study, of standardised method for the determination of mono- and diacylglycerols in vegetable oils and fats is described. The method involves separation of mono- and diacylglycerols by normal phase high-performance liquid-liquid chromatography (HPLC) and evaporative light scattering detection of a solution of oil, fat or a commercial mono- and diacylglycerol preparation in a organic solvent.

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Nitrate and nitrite poisoning in sheep and goats caused by ingestion of Portulaca oleracea

Pesquisa Veterinária Brasileira ◽

10.1590/1678-5150-pvb-5550 ◽

2018 ◽

Vol 38 (8) ◽

pp. 1549-1553

Author(s):

João G. Simões ◽

Rosane Maria T. Medeiros ◽

Márcia A. Medeiros ◽

Robério G. Olinda ◽

Antônio Flávio M. Dantas ◽

...

Keyword(s):

Methylene Blue ◽

Body Weight ◽

Clinical Signs ◽

Portulaca Oleracea ◽

Sheep And Goats ◽

Ruminal Ph ◽

The Third ◽

Mucous Membranes ◽

Nitrate And Nitrite ◽

Positive Results

ABSTRACT: Three outbreaks of poisoning by Portulaca oleracea were reported in sheep and goats in Northeast Brazil. In the first outbreak, 8 out of 20 sheep were affected and later died. In the second outbreak, three goats and one sheep died out of a flock of 30 animals that included both species. In the third outbreak, two out of 19 sheep were affected, and they recovered after a treatment of 2% methylene blue at a dose of 4 mg/kg body weight. In the first and second outbreaks, the animals ingested P. oleracea after it was cut and offered in feeders. In the third outbreak, the flock was grazing in an area that had been invaded by the plant. To determine the toxicity, P. oleracea was administered experimentally at a dose of 80g/kg of body weight to seven sheep, weighing 19-30 kg. One control sheep received green grass. One to four hours after P. oleracea ingestion, the animals showed clinical signs of poisoning characterized by cyanotic mucous membranes, bloat, ruminal pH of 8-9, pollakiuria, aerophagia, involuntary movements of the upper lip, apathy, tachypnea and tachycardia. Five animals recovered, including one that was treated with 1% methylene blue, and two animals died. During necropsy, the mucous membranes were brownish, and the blood was dark brown. Diphenylamine tests of the plant and of rumen contents were positive for nitrates. Positive results for nitrates were also found in 24 samples of P. oleracea that were collected in different places in the states of Pernambuco and Paraíba. We conclude that P. oleracea accumulates nitrates at toxic levels and may cause poisoning in sheep and goats.

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RAZOR™ EX Anthrax Air Detection System for Detection of Bacillus anthracis Spores from Aerosol Collection Samples: Collaborative Study

Journal of AOAC International ◽

10.5740/jaoacint.cs2012-06 ◽

2013 ◽

Vol 96 (2) ◽

pp. 392-398 ◽

Cited By ~ 6

Author(s):

Ted Hadfield ◽

Valorie Ryan ◽

Usha K Spaulding ◽

Kristine M Clemens ◽

Irene M Ota ◽

...

Keyword(s):

Confidence Interval ◽

Bacillus Anthracis ◽

Detection System ◽

Collaborative Study ◽

Probability Of Detection ◽

Data Sets ◽

Method Performance ◽

Bacillus Anthracis Spores ◽

Phosphate Buffered Saline ◽

Positive Results

Abstract The RAZOR™ EX Anthrax Air Detection System was validated in a collaborative study for the detection of Bacillus anthracis in aerosol collection buffer. Phosphate-buffered saline was charged with 1 mg/mL standardized dust to simulate an authentic aerosol collection sample. The dust-charged buffer was spiked with either B. anthracis Ames at 2000 spores/mL or Bacillus cereus at 20 000 spores/mL. Twelve collaborators participated in the study, with four collaborators at each of three sites. Each collaborator tested 12 replicates of B. anthracis in dust-charged buffer and 12 replicates of B. cereus in dust-charged buffer. All samples sets were randomized and blind-coded. All collaborators produced valid data sets (no collaborators displayed systematic errors) and there was only one invalid data point. After unblinding, the analysis revealed a cross-collaborator probability of detection (CPOD) of 1.00 (144 positive results from 144 replicates, 95% confidence interval 0.975–1.00) for the B. anthracis samples and a CPOD of 0.00 (0 positive results from 143 replicates, 95% confidence interval 0.00–0.0262) for the B. cereus samples. These data meet the requirements of AOAC Standard Method Performance Requirement 2010.003, developed by the Stakeholder Panel on Agent Detection Assays.

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Design and Conduct of Collaborative Studies: CIPAC Collaborative Experience in Pesticide Formulations

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/69.3.408 ◽

1986 ◽

Vol 69 (3) ◽

pp. 408-409

Author(s):

J Henriet ◽

A Martijn

Keyword(s):

Collaborative Study ◽

Final Decision ◽

Collaborative Trial ◽

Collaborative Studies ◽

Interlaboratory Studies ◽

Pesticide Formulations ◽

Study Evaluation ◽

Set Up

Abstract CIPAC has set up procedures for carrying out interlaboratory studies on analysis of technical pesticide materials and formulations. CIPAC studies comprise several steps: allocation of leadership; method survey and selection; pre-collaborative trial; full collaborative study; evaluation of results and final decision on acceptance.

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Results of a Multicenter Study Assessing the Status of Standardization of a Recombinant Thromboplastin for the Control of Oral Anticoagulant Therapy

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648850 ◽

1994 ◽

Vol 72 (02) ◽

pp. 261-267 ◽

Cited By ~ 17

Author(s):

A Tripodi ◽

V Chantarangkul ◽

M Braga ◽

L poller ◽

J W ten Cate ◽

...

Keyword(s):

Statistical Analysis ◽

Oral Anticoagulant Therapy ◽

Oral Anticoagulants ◽

Collaborative Study ◽

The Third ◽

Normal Individuals ◽

The Status ◽

Data Points ◽

Relationship Of ◽

International Collaborative Study

SummaryAn international collaborative study involving 20 laboratories was undertaken to evaluate the status of standardization of a commerical recombinant thromboplastin. The results show that the reagent fulfills the WHO requirements for thromboplastin calibration against two International Reference Preparations (IRP) from different species, because there was a linear relationship of log-transformed prothrombin times as measured by the recombinant reagent and the two IRPs in normal individuals and patients stabilized on oral anticoagulants. The regression lines drawn through the patient data points passed through the normal data points in the majority of instances. The average ISI values for three different batches were close to unity. On the average, the ISI value calculated against BCT/253 (human, plain) was slightly smaller than that against RBT/79 (rabbit, plain). The between laboratory precision of calibration (CV = 5-6%) did not change whether BCT/253 or RBT/79 was used, whereas it was substantially improved when the calibrations of batches 2 and 3 were performed against batch 1, arbitrarily taken as standard (CV ≤ 1.7%). Statistical analysis to test for differences between slopes revealed no significant between-batch differences in 16 of 20 laboratories. However slight differences for the third batch (2.8% less than the average ISI value of batches 1 and 2) leave room for further improvement in the standardization of the reagent.

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