Automation of the Flame Photometric Method for Potassium in Fertilizer Grade Potassium Salts

1965 ◽  
Vol 48 (4) ◽  
pp. 865-868
Author(s):  
James P Ussary ◽  
Charles W Gehrke
Keyword(s):  
Photometric Method ◽  
Potassium Salts ◽  
Considerable Saving ◽  
Large Numbers ◽  
Relative Standard ◽  
Aoac Official ◽  
Standard Deviations ◽  
Flame Method ◽  
Analytical Time

Abstract Five selected commercial salts and two reagent grade salts were analyzed for potassium at least 10 times independently by both the automatic flame photometric method and the AOAC official STPB method. The flame photometric results were as precise and accurate as the official STPB results. The relative standard deviations were 0.36% K2O for the automated flame method and 0.32% K2O for the STPB method. The averages of the results (100.1%) on the reagent grade salts were very close to the theoretical values. The automatic flame photometric method for potassium in fertilizer grade potassium salts is accurate and precise, and results in a considerable saving in analytical time, especially for laboratories routinely analyzing large numbers of samples.

Automatic Flame Photometric Determination of Potassium in Fertilizers. A. Elimination of Anion Exchange Cleanup. B. Using Direct Available P2O5 Extract

1965 ◽  
Vol 48 (6) ◽  
pp. 1095-1100
Author(s):  
James P Ussary ◽  
Charles W Gehrke
Keyword(s):  
Anion Exchange ◽  
Primary Standard ◽  
Photometric Determination ◽  
Photometric Method ◽  
Potassium Salts ◽  
Commercial Fertilizer ◽  
Aoac Official ◽  
Primary Standards ◽  
Standard Grade

Abstract Three primary standard grade potassium salts, eight Magruder check samples, and 18 commercial fertilizer samples were analyzed by three methods. Primary standards gave an average recovery of 100.0% and an average range of 0.21% K20. Magruder check samples averaged 0.09% K20 higher by the modified flame photometric method than the grand averages of the STPB results on the respective Magruder reports. The modified flame photometric method averaged 0.02% K20 lower than the official flame photometric method and 0.11% K20 higher than the official STPB method on 18 commercial fertilizer samples. The automatic flame photometric method, without anion exchange cleanup, is rapid enough for routine analysis and is as accurate and precise as the AOAC official methods. The method was also applied to the direct available P205 extract. Results on three primary grade potassium salts, seven Magruder check samples, and 13 commercial fertilizer samples were as accurate and precise as the official STPB method.

Automation of the AOAC Photometric Phosphomolybdovanadate Method for Direct Available P2O5

1966 ◽  
Vol 49 (6) ◽  
pp. 1213-1218
Author(s):  
Charles W Gehrke ◽  
James H Baumgartner ◽  
James P Ussary
Keyword(s):  
Sampling Rate ◽  
Gravimetric Method ◽  
Photometric Method ◽  
Available Phosphorus ◽  
Automatic Method ◽  
Average Recovery ◽  
Automated Method ◽  
Relative Standard ◽  
Standard Deviations

Abstract An automatic photometric method utilizing the Technicon AutoAnalyzer has been developed to determine phosphorus in all forms of fertilizer phosphorus in the range of 2.0–4.5 mg P2O5/100 ml at a sampling rate of 40 analyses/hr. Multiple analyses of KH2PO4, 9 Magruder check samples, and numerous commercial fertilizers were made and compared with results obtained by the official quinolinium phosphomolybdate method, 2.025(b). Average range for five independent determinations was 0.22% P2O5 for the automated method and 0.26% P2O5 for the gravimetric method; average relative standard deviations were 0.44 and 0.60%, respectively. The average recovery of P2O5 from KH2PO4 was 99.8% with the photometric method and 100.3% with the quinolinium method. Results on 69 commercial fertilizers containing 5–54% P2O5 by the automatic method were only 0.02%% lower than those by the gravimetric quinolinium method. Results show that the automated phosphomolybdovanadate method for direct available phosphorus in fertilizers is accurate, precise, and less time consuming for routine control and industrial laboratories.

Automated Spectrophotometric Method for Nitrogen in Fertilizers

1968 ◽  
Vol 51 (1) ◽  
pp. 200-211
Author(s):  
Charles W Gehrke ◽  
Floyd E Kaiser ◽  
James P Ussary
Keyword(s):  
Alkaline Medium ◽  
Spectrophotometric Method ◽  
Primary Standard ◽  
Considerable Saving ◽  
Comparison Of Results ◽  
Automated Method ◽  
Large Numbers ◽  
Analytical Time ◽  
Standard Grade

Abstract An automated spectrophotometric method utilizing the Technicon Autoanalyzer has been developed to determine nitrogen in fertilizer digestates in the range from 5 to 15 ppm nitrogen at a rate of 40 analyses per hour. NH4 is determined by reacting it with phenol and hypochlorite in an alkaline medium to form a blue compound closely related to indole phenol. Optimum reagent concentrations for the colored reaction were determined, and several ions were investigated to determine if they interfere with the reaction. Comparison of results obtained by the automated method and the comprehensive nitrogen method in primary standard grade NH4SO4 and KN03, Magruder check samples, and several commercial fertilizers show that the automated method is accurate and precise. The automated method results in considerable saving of analytical time, especially in laboratories analyzing large numbers of samples

Automation of the AOAC Flame Photometric Method for Potassium in Fertilizers

1964 ◽  
Vol 47 (3) ◽  
pp. 459-469
Author(s):  
Charles W Gehrke ◽  
James P Ussary ◽  
George H Kramer
Keyword(s):  
Ion Exchange ◽  
Emission Intensity ◽  
Intensity Ratio ◽  
Photometric Method ◽  
Automatic Method ◽  
Automatic Instrument ◽  
Considerable Saving ◽  
Analytical Time ◽  
Interfering Ions ◽  
Emission Intensity Ratio

Abstract A study was undertaken to (a) develop a simple, rapid, accurate, and automatic method for routinely determining potassium in commercial fertilizers; (b) to determine the effect of different concentrations of common interfering ions on the emission intensity ratio of potassium in KNO3 standards; (c) to eliminate the ion exchange cleanup of sample and thus simplify the method; and (d) to evaluate the automatic instrument. Phosphate was the only ion that caused a serious effect. The cleanup was found to be unnecessary for fertilizers containing less than 16% K2O, but gives more accurate results for higher concentration fertilizers. The automatic method gave accurate and precise results, and effected considerable saving in analytical time.

scholarly journals Gas Chromatographic Method for Putrescine and Cadaverine in Canned Tuna and Mahimahi and Fluorometric Method for Histamine (Minor Modification of AOAC Official Method 977.13): Collaborative Study

1997 ◽  
Vol 80 (3) ◽  
pp. 591-602 ◽  
Author(s):  
Patricia L Rogers ◽  
Walter Staruszkiewicz ◽  
A Adams ◽  
B Atienza ◽  
R J Berg ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Official Method ◽  
Fluorometric Method ◽  
Canned Tuna ◽  
Relative Standard ◽  
Aoac Official ◽  
Standard Deviations ◽  
Ppm Level ◽  
Aoac Official Method

Abstract A collaborative study was conducted to test a modification to the AOAC fluorometric method for histamine (AOAC® Official Method 977.13) that substitutes 75% methanol as the extracting solvent. All other steps remain unchanged. The extracts prepared with 75% methanol were also used to collaboratively test a gas chromatographic (GC) method for determination of putrescine and cadaverine in seafood. In the GC method, the extracted diamines are converted to fluorinated derivatives, the reaction mixtures are passed through solid-phase extraction columns, and the derivatives are quantitated by electron capture GC after separation on an OV-225 column. Fourteen laboratories using the GC method for putrescine and cadaverine and 16 laboratories using the fluorometric method for histamine analyzed 14 canned tuna and raw mahimahi (including blind duplicates and a spike) containing 0.2-2.6 ppm putrescine, 0.6-9.1 ppm cadaverine, and 0.6-154 ppm histamine. At the 5 ppm level, recoveries ranged from 71 to 102% for putrescine and 77 to 112% for cadaverine; the respective repeatability relative standard deviations (RSDr) were 5.2 and 15%, and the respective reproducibility relative standard deviations (RSDR) were 8.8 and 18%. At the 50 ppm level, histamine recoveries ranged from 84 to 125%, RSDr was 3.6%, and RSDR was 9.4%. The GC method for determination of putrescine in canned tuna and cadaverine in canned tuna and mahimahi has been adopted first action by AOAC INTERNATIONAL, and the AOAC Official Method 977.13, Histamine in Seafood, Fluorometric Method, has been modified

Spectrophotometric Determination of Nitrate in Baby Foods: Collaborative Study

1994 ◽  
Vol 77 (2) ◽  
pp. 425-430 ◽  
Author(s):  
Anna-Maua K Sjöberg ◽  
Timo A Alanko
Keyword(s):  
Collaborative Study ◽  
Photometric Method ◽  
Chromatographic Technique ◽  
Baby Foods ◽  
Relative Standard ◽  
Food Matrices ◽  
Standard Deviations ◽  
Liquid Chromatographic ◽  
Concentration Levels

Abstract A collaborative study was conducted of a spectro-photometric method for determination of nitrate after cadmium reduction to nitrite in baby foods containing meat. Thirty-one municipal and 2 industrial food laboratories participated in the study. The study design involved 2 baby food matrices. Samples of both matrices were prepared at 3 concentration levels between 52 and 309 mg NaNO3/kg as blind duplicates. A blank without added nitrate was also included. The outlier percentage of the results was very low (4.3%). It was typical for the method that recoveries were slightly >100%. Recoveries for baby foods varied between 113.3 and 116.9%, and were acceptable for control purposes. The relative standard deviations for repeatability were 5.0–18.1%. The relative standard deviations for reproducibility were 8.3–21.6%. Three collaborators also evaluated liquid chromatographic technique for nitrate determinations. These preliminary results are presented but are not analyzed statistically. The spectrophotometric method was adopted first action by AOAC INTERNATIONAL.

scholarly journals Quantitative Detection of Chromium Pollution in Biochar Based on Matrix Effect Classification Regression Model

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2069
Author(s):  
Mei Guo ◽  
Rongguang Zhu ◽  
Lixin Zhang ◽  
Ruoyu Zhang ◽  
Guangqun Huang ◽  
...  
Keyword(s):  
Regression Model ◽  
Matrix Effect ◽  
Nearest Neighbor ◽  
Quantitative Detection ◽  
Least Squares Regression ◽  
K Nearest Neighbor ◽  
Breakdown Spectroscopy ◽  
Relative Standard ◽  
Calibration Samples ◽  
Standard Deviations

Returning biochar to farmland has become one of the nationally promoted technologies for soil remediation and improvement in China. Rapid detection of heavy metals in biochar derived from varied materials can provide a guarantee for contaminated soil, avoiding secondary pollution. This work aims first to apply laser-induced breakdown spectroscopy (LIBS) for the quantitative detection of Cr in biochar. Learning from the principles of traditional matrix effect correction methods, calibration samples were divided into 1–3 classifications by an unsupervised hierarchical clustering method based on the main elemental LIBS data in biochar. The prediction samples were then divided into diverse classifications of calibration samples by a supervised K-nearest neighbor (KNN) algorithm. By comparing the effects of multiple partial least squares regression (PLSR) models, the results show that larger numbered classifications have a lower averaged relative standard deviations of cross-validation (ARSDCV) value, signifying a better calibration performance. Therefore, the 3 classification regression model was employed in this study, which had a better prediction performance with a lower averaged relative standard deviations of prediction (ARSDP) value of 8.13%, in comparison with our previous research and related literature results. The LIBS technology combined with matrix effect classification regression model can weaken the influence of the complex matrix effect of biochar and achieve accurate quantification of contaminated metal Cr in biochar.

scholarly journals Simultaneous Determination of Nitroimidazoles and Quinolones in Honey by Modified QuEChERS and LC-MS/MS Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Haiyan Lei ◽  
Jianbo Guo ◽  
Zhuo Lv ◽  
Xiaohong Zhu ◽  
Xiaofeng Xue ◽  
...  
Keyword(s):  
Recovery Rates ◽  
Inhibition Effect ◽  
Standard Curve ◽  
Modified Quechers ◽  
Relative Standard ◽  
Acacia Honey ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Standard Deviations

This study reports an analytical method for the determination of nitroimidazole and quinolones in honey using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A modified QuEChERS methodology was used to extract the analytes and determine veterinary drugs in honey by LC-MS/MS. The linear regression was excellent at the concentration levels of 1–100 ng/mL in the solution standard curve and the matrix standard curve. The recovery rates of nitroimidazole and quinolones were 4.4% to 59.1% and 9.8% to 46.2% with relative standard deviations (RSDs) below 5.2% and the recovery rates of nitroimidazole and quinolones by the matrix standard curve ranged from 82.0% to 117.8% and 79% to 115.9% with relative standard deviations (RSDs) lower than 6.3% in acacia and jujube honey. The acacia and jujube honeys have stronger matrix inhibition effect to nitroimidazole and quinolones residue; the matrix inhibition effect of jujube honey is stronger than acacia honey. The matrix standard curve can calibrate matrix effect effectively. In this study, the detection method of antibiotics in honey can be applied to the actual sample. The results demonstrated that the modified QuEChERS method combined with LC-MS/MS is a rapid, high, sensitive method for the analysis of nitroimidazoles and quinolones residues in honey.

Microbial Receptor Assay for Rapi d Detection and Identification of Seven Families of Antimicrobial Drugs in Milk: Collaborative Study

1988 ◽  
Vol 71 (2) ◽  
pp. 304-316 ◽  
Author(s):  
Stanley E Charm ◽  
Ruey Chi
Keyword(s):  
Binding Sites ◽  
Specific Binding ◽  
Scintillation Counter ◽  
Collaborative Study ◽  
False Negative ◽  
Penicillin G ◽  
Specific Binding Sites ◽  
Receptor Assay ◽  
Relative Standard ◽  
Standard Deviations

Abstract A microbial competitive receptor assay for detecting residues of antibiotic families in milk was studied collaboratively by 13 laboratories. The drugs and levels (ppb) tested in this study i nclude penicillin G, 4.8; cephapirin, 5.0; cloxacillin, 100; tetracycline, 2000; chlortetracycline, 2000; oxytetracycline, 2000; erythromycin, 200; lincomycin, 400; clindamycin, 400; sulfamethazine, 75; sulfamethoxazole, 50; sulfisoxazole, 50; streptomycin, 1000; novobiocin, 50; and chloramphenicol, 800. In this method, microbial cells added to a milk sample provide specific binding sites for which 14C or 3H libeled drug competes with drug residues in the sample. The UC or H binding to the specific binding sites is measured in a scintillation counter and compared with a zero standard milk. If the sample is statistically different from the zero standard, it is positive. The assay takes about 15 min. The binding reaction occurs between the receptor site and the drug functional group, so all members of a drug family are detected. In this case, beta-lactams, tetracyclines, macrolides, aminoglycosides, novobiocin, chloramphenicol, and sulfonamides, including/^-aminobenzoic acid (PABA) and its other analogs, are detectable. The incidence of false negative determinations among samples is about 1%; the incidence of false positives is about 3%. For negative cases, the relative standard deviations for repeatability ranged from 0 to 5% and for reproducibility from 0 to 6%. For positive cases, relative standard deviations ranged from 0 to 13% for repeatability and from 0 to 14% for reproducibility. The method has been adopted official first action.

Semia u torn ate d Method for the Analysis of Methyltestosterone Tablets and Testosterone Suspensions

1972 ◽  
Vol 55 (6) ◽  
pp. 1175-1179
Author(s):  
James W Myrick ◽  
Donald P Page ◽  
Yvonne H Pfabe
Keyword(s):  
Active Ingredient ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Alcoholic Solution ◽  
Isonicotinic Acid Hydrazide ◽  
Yellow Color ◽  
Relative Standard ◽  
Standard Deviations ◽  
Analytical System

Abstract A semiautomated analytical system has been developed to determine the amount of methyltestosterone in single tablets at a level of 5–25 mg/tablet or testosterone in suspensions. The active ingredient in an alcoholic solution was acidified and the drug was extracted into chloroform. Reaction with isonicotinic acid hydrazide produced a yellow color, which was recorded on a colorimeter. Relative standard deviations of the method did not exceed 1.38 and 1.50% for methyltestosterone tablets and testosterone suspensions, respectively.

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