A COLLABORATIVE STUDY OF METHODS FOR THE DETERMINATION OF POTASSIUM, CALCIUM AND MAGNESIUM IN PLANT MATERIALS

1960 ◽  
Vol 40 (4) ◽  
pp. 589-595 ◽  
Author(s):  
G. M. Ward ◽  
H. B. Heeney
Keyword(s):  
Plant Tissue ◽  
Collaborative Study ◽  
Plant Materials ◽  
Reliable Determination ◽  
Flame Photometer ◽  
Methods Of Analysis ◽  
Calcium And Magnesium

Thirteen Canadian laboratories collaborated in a 2-year study of methods of analysis of plant tissue. The investigation has shown that the flame photometric procedure for potassium and a modification of the chelatometric method using EDTA for calcium and magnesium give the most consistent and reproducible results. Further research is necessary before the flame photometer can be used for the reliable determination of calcium and magnesium.

Pyrolysis-Gas Chromatographic Techniques for the Analysis of Automobile Finishes: Collaborative Study

1976 ◽  
Vol 59 (1) ◽  
pp. 35-41 ◽  
Author(s):  
William D Stewart
Keyword(s):  
Mass Spectrometry ◽  
Infrared Spectroscopy ◽  
Collaborative Study ◽  
Pyrolysis Gas ◽  
Analytical Technique ◽  
Organic Vehicle ◽  
Unknown Sample ◽  
Chromatographic Techniques ◽  
Methods Of Analysis

Abstract Samples of 7 automobile topcoats currently used by the major American automobile manufacturers were analyzed by various pyrolysis-gas chromatographic techniques. The samples were similar shades of white paint with small differences in the organic vehicle composition. The study involved analysis of the 7 samples and identification of an unknown sample chosen from the 7. A ninth chip was also included for determination of the reproducibility of the analytical technique. The samples were analyzed by other methods of analysis, including diamond cell infrared spectroscopy and mass spectrometry. Sample sizes from 4 to 200 μg were needed for the various methods of analysis and, in all cases, the unknown sample was correctly identified.

Determination of Potassium in Plant Materials with a Flame Photometer

1952 ◽  
Vol 35 (4) ◽  
pp. 813-816
Author(s):  
Betty R Johnston ◽  
C W Duncan ◽  
Kirk Lawton ◽  
E J Benne
Keyword(s):  
Plant Materials ◽  
Flame Photometer

Determination of Sodium in Fertilizers by Flame Photometer

1965 ◽  
Vol 48 (2) ◽  
pp. 398-400
Author(s):  
Bertram Gersten
Keyword(s):  
Collaborative Study ◽  
Photometric Method ◽  
Flame Photometer

Abstract A collaborative study was conducted on a flame photometric method for sodium in fertilizers. The method is an “outgrowth” of the AOAC flame potash method, with simple modifications. Data show that the method is precise, and it is recommended for adoption as official, first action.

Atomic Absorption Spectrophotometric Determination of Calcium and Magnesium and Colorimetric Determination of Phosphorus in Cheese: Collaborative Study

1991 ◽  
Vol 74 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Roger M Pollman
Keyword(s):  
Atomic Absorption ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Colorimetric Determination ◽  
The Third ◽  
Number Of Factors ◽  
Relative Standard ◽  
Calcium Phosphorus ◽  
Calcium And Magnesium

Abstract The determination of calcium, phosphorus, and magnesium In cheese was collaboratively studied. The sample is dried and ashed and the residue is dissolved In an acidified aqueous solution. Calcium and magnesium are determined by atomic absorption spectrophotometry and phosphorus Is determined by colorlmetry. The study was repeated 3 times because of high within- and between-laboratory relative standard deviations (RSDr and RSDR, respectively). Poor precision In the first 2 studies was caused by a number of factors, Including use of contaminated glassware, Improperly maintained Instruments, and Impure reagents as standards. In each study, 5 varieties of cheese were distributed as 10 blind duplicate samples along with a practice sample. Thirteen laboratories participated in the third study, which was generally problem-free. The range of results and the average RSDr and RSDR found In the cheeses were: calcium, 608- 1107 mg/100 g, 1.5%, 2.6%; magnesium, 23.9-50.6 mg/ 100 g, 2.8%, 3.8%; phosphorus, 444-695 mg/100 g, 1.2%, 1.6%. The method has been adopted official first action by AOAC.

Rapid Flame Photometric Method for Sodium in Fruits

1966 ◽  
Vol 49 (3) ◽  
pp. 617-619
Author(s):  
Feederick E Boland
Keyword(s):  
Drug Administration ◽  
Food And Drug Administration ◽  
Collaborative Study ◽  
Sample Solution ◽  
Photometric Method ◽  
Collaborative Testing ◽  
Flame Photometer ◽  
Distilled Spirits

Abstract The flame photometric method of Pro and Mathers for sodium in wines and distilled spirits has been adapted to the analysis of sample solutions of fruit and subjected to collaborative testing. A sample solution of fruit is aspirated directly into the flame photometer, which eliminates the need for ashing the sample and thus effects a saving of time. Six Food and Drug Administration District Laboratories, two State laboratories, and the Associate Referee participated in the collaborative study. The results indicate that the method is sufficiently accurate for the determination of sodium in fruit, and the method is recommended for adoption as official, first action.

Elemental Analysis of Plant Tissue by Plasma Emission Spectroscopy: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 499-505 ◽  
Author(s):  
Robert A Isaac ◽  
William C Johnson
Keyword(s):  
Plant Tissue ◽  
Emission Spectroscopy ◽  
Collaborative Study ◽  
Plasma Emission ◽  
Tissue Samples ◽  
Coefficients Of Variation ◽  
Aoac Method ◽  
Preparation Errors ◽  
Plasma Emission Spectroscopy

Abstract Fourteen laboratories participated in a collaborative study of 6 homogeneous plant tissue samples to determine the elements P, K, Ca, Mg, Mn, Fe, Al, B, Cu, Zn, and Na by plasma emission spectroscopy. Samples were dry ashed using AOAC method 3.007(a) (13th Ed.). An NBS citrus leaf standard was prepared and a portion of the resulting solution was sent to each collaborator to evaluate sample preparation errors independent of instrument error. Coefficients of variation were better than those obtained in an earlier collaborative study on multielement analysis by spark emission spectroscopy. The plasma emission method has been adopted official first action for determination of P, K, Ca, Mg, Mn, B, Cu, and Zn in plant tissues.

Determination of Calcium and Magnesium in Fertilizers by EDTA Titrations: A Collaborative Study

1964 ◽  
Vol 47 (3) ◽  
pp. 450-456
Author(s):  
John B Smith ◽  
Peter B Manning
Keyword(s):  
Collaborative Study ◽  
Official Method ◽  
Calcium And Magnesium

Abstract Collaborative analyses of nine fertilizers by eight analysts at seven laboratories demonstrated that the EDTA method for magnesium is equally accurate and more precise when compared with the longer official methods. Neither the EDTA method nor official method 2.085 was satisfactory for all samples. The EDTA method for magnesium will not tolerate more than 0.25% of manganese or zinc.

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