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.

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.

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.

Collaborative Study of Automated Determination of Phosphorus in Meat Products

1972 ◽  
Vol 55 (1) ◽  
pp. 123-127
Author(s):  
Walter M Gantenbein
Keyword(s):  
Room Temperature ◽  
Phosphorus Content ◽  
Collaborative Study ◽  
Meat Products ◽  
Average Standard Deviation ◽  
Colorimetric Measurement ◽  
Automated Method ◽  
Average Coefficient ◽  
Automated Determination

Abstract A collaborative study has been conducted on a modification of a previously reported automated method for phosphorus in meat products. Samples were dissolved in 1 + 1 sulfuric acid, cooled to room temperature, and presented to an AutoAnalyzer system. Digestion, dilution, and colorimetric measurement of phosphorus content were performed automatically. Six collaborators participated in the study, analyzing 8 different samples in duplicate. Results of the study were good, with an average range of 0.012% P, average standard deviation of ±0.0047, and average coefficient of variation of 2.32%. The method is recommended for adoption as official first action.

Collaborative Study of an Automated Method for the Determination of Total and Direct Available P2O5 in Fertilizers

1973 ◽  
Vol 56 (5) ◽  
pp. 1084-1086
Author(s):  
Frank J Johnson
Keyword(s):  
Collaborative Study ◽  
T Test ◽  
Official Method ◽  
Matched Pairs ◽  
F Test ◽  
Automated Method

Abstract In a collaborative study, an automated method for the determination of total and direct available P2O5 was compared with the official gravimetric quinolinium molybdophosphate method, 2.023–2.025. Nine laboratories participated in the analysis of the 12 sample solutions, and the results were evaluated by the technique of closely matched pairs. The t-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 not 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.

Automated Method for the Determination of Niacin and Niacinamide in Cereal Products: Collaborative Study

1975 ◽  
Vol 58 (4) ◽  
pp. 799-803
Author(s):  
Anthony F Gross
Keyword(s):  
Chemical Method ◽  
Collaborative Study ◽  
Pet Food ◽  
Microbiological Method ◽  
Chemical Methods ◽  
Cereal Products ◽  
Automated Method ◽  
Coefficients Of Variation ◽  
Baked Products

Abstract In a collaborative study, an automated method for the determination of niacin and niacinamide in cereal products was compared with the official final action microbiological (43.121–43.125) and chemical (43.044–43.046) methods. Ten samples of cereal products, including enriched flour, yeast-leavened baked products, fortified breakfast cereals, and baked pet food products, were submitted to 14 laboratories. Nine laboratories reported values by the automated method, 6 reported values by the microbiological method, and 7 reported values by the chemical method. The results from the microbiological method were not subjected to analysis of variance because of the unusually large between-laboratory variation. The between-laboratory coefficients of variation for the automated and chemical methods were 10.90 and 10.18%, on the basis of results from 7 and 4 laboratories, respectively. There was no significant (p>0.05) difference between methods when results from the 4 laboratories who used both methods were compared. The automated chemical method has been adopted as official first action.

Automated Determination of Free Amino Groups in Serum and Plasma Using 2,4,6-Trinitrobenzene Sulfonate

1969 ◽  
Vol 15 (9) ◽  
pp. 891-901 ◽  
Author(s):  
D W Palmer ◽  
T Peters
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Clinical Applications ◽  
Amino Groups ◽  
Automated Method ◽  
Total Free Amino Acids ◽  
Colored Complexes ◽  
Automated Determination

Abstract A simple automated method is described for determining the level of total free amino acids in the blood. The method utilizes the AutoAnalyzer, and is based on the formation of colored complexes by uniting free amino groups with 2,4,6-trinitrobenzene sulfonate (TNBS). Proteins do not interfere because the free amino acids are first separated by dialysis. Characteristics of the reaction and potential clinical applications of the procedure are discussed.

Collaborative Study of the Milko-Tester Method for Measuring Fat in Homogenized and Unhomogenized Milk

1975 ◽  
Vol 58 (3) ◽  
pp. 572-575
Author(s):  
W Frank Shipe ◽  
Gary F Senyk
Keyword(s):  
Collaborative Study ◽  
Calibration Standards ◽  
Milk Samples ◽  
Automated Method ◽  
Standard Deviations

Abstract The Mark III Industrial Model Milko-tester was evaluated to determine its reliability for testing both unhomogenized and homogenized milk samples. Six laboratories participated in 2 trials. In the first trial, the range among laboratories for homogenized milk was 0.29% and unhomogenized milk 0.34%. This variation was apparently due to inaccurate calibrations. In the second trial, 2 calibration standards were used for each type of milk and the range was reduced to 0.04% for homogenized milk and 0.05% for unhomogenized milk. The standard deviations for unhomogenized and homogenized milk were 0.008 and 0.010 for trial 1 and 0.005 and 0.005 for trial 2, respectively. The official first action automated method I for the determination of fat in raw, unhomogenized milk has been expanded to include the determination of fat in homogenized milk by the use of the Mark III Industrial Model Milko-tester.

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.

Method for Fully Automated Determination of Total Cholesterol in Blood Serum, Including Saponification and Extraction

1968 ◽  
Vol 14 (10) ◽  
pp. 960-966 ◽  
Author(s):  
J van der Honing ◽  
C C Saarloos ◽  
J Stip
Keyword(s):  
Carbon Tetrachloride ◽  
Blood Serum ◽  
Total Cholesterol ◽  
Standard Error ◽  
New Method ◽  
Automated Method ◽  
The Relationship ◽  
Cholesterol Determination ◽  
Automated Determination

Abstract A fully automated method has been developed for the determination of total cholesterol in blood serum, using the AutoAnalyzer system. According to the new method, based on the cholesterol determination of Abell et al. (1), the serum sample is saponified and subsequently extracted with carbon tetrachloride. After treatment with Liebermann-Burchard reagent, the amount of cholesterol is determined at 630 nm. The method can be used for free and esterified cholesterol because saponification is carried out. The relationship between the new method and that of Abell et al. is linear. The correlation coefficient is 0.98 and the standard error 1.5%. According to the new method, 30 samples can be analyzed per hour.

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