Rapid Ammonium Citrate Extraction Method for Determination of Available Phosphorus

1967 ◽  
Vol 50 (6) ◽  
pp. 1273-1279
Author(s):  
Gordon O Guerrant ◽  
J D Hunter ◽  
C H Mcbride
Keyword(s):  
Quality Control ◽  
Extraction Method ◽  
Direct Determination ◽  
Ammonium Citrate ◽  
Available Phosphorus ◽  
Gooch Crucible

Abstract Available phosphorus has been determined in fertilizers by a quick extraction method useful for screening or quality control purposes. Samples were extracted in a Gooch crucible with a jet of 65 °C neutral ammonium citrate in 10—20 mill. A single direct determination of available phosphorus was made by the alkalimetric quimociac method, modified for speed and for use in high citrate concentrations. The results compare favorably in accviracy to the gravimetric quimociac results reported on 20 Magruder check fertilizer samples

Quinoline Molybdate Method for the Determination of Water-Soluble and Available Phosphorus in Fertilizers

1963 ◽  
Vol 46 (4) ◽  
pp. 570-579
Author(s):  
W M Hoffman ◽  
R J Ferretti ◽  
H J Breen
Keyword(s):  
Acid Hydrolysis ◽  
Collaborative Study ◽  
Direct Determination ◽  
Volumetric Method ◽  
Water Soluble ◽  
Ammonium Citrate ◽  
Available Phosphorus ◽  
Soluble Extract ◽  
Molybdate Method

Abstract Addition of a separate acid hydrolysis step in the determination of watersoluble phosphorus was found necessary in the official volumetric method but not in the quinoline molybdate method. By carefully controlling the phosphorus and ammonium citrate concentrations in the direct determination of available phosphorus, phosphorus can be completely precipitated as quinoline phosphomolybdate. The nitration of the ammonium citrate digestate in preparing the combined water-soluble and citrate-soluble extract for direct determination of available phosphorus can be eliminated. The latter two observations were supported by the results of a collaborative study by 8 analysts on 8 fertilizer materials.

Detection of L-Tert-Leucine in the Enzyme-Catalyzed Reaction System

2013 ◽  
Vol 641-642 ◽  
pp. 717-720
Author(s):  
Sheng Deng ◽  
Li Cui ◽  
Li Min Ma
Keyword(s):  
Quality Control ◽  
Correlation Coefficient ◽  
Flow Rate ◽  
Catalytic Reaction ◽  
Reaction System ◽  
Direct Determination ◽  
Average Recovery ◽  
Enzyme Catalytic Reaction

Direct Determination of L-Ter-Leucine in Enzyme Catalytic Reaction System by HPLC Was Studied. the Detection Were Performed on a Kromasil 700-5C18 Column Using a Eluant Containing 0.25% (NH4)H2PO4 and 100% Methanol (V((NH4)H2PO4):V(methanol)=100:5) with the Flow Rate of 0.8 Ml/min at,detection Wavelength of 205nm. there Was a Good Line Correlation between Peak Area and Contents in the Rang of 0.2-10 Mg/ml, the Correlation Coefficient Was 0.9986, the Average Recovery Was 98.88% with a Relative Stand Deviation of 0.78% (n=5). this Method Is Simple, Stable, Accurate and Reliable for the Quality Control of L–ter-Leucine.

Spectrophotometric Method for the Direct Determination of Available Phosphorus in Fertilizers: Use of Dry Ashing to Destroy Citrate

1965 ◽  
Vol 48 (4) ◽  
pp. 859-865
Author(s):  
Wallace S Brammell
Keyword(s):  
Spectrophotometric Method ◽  
Direct Determination ◽  
Available Phosphorus ◽  
Hot Plate ◽  
Erlenmeyer Flask ◽  
White Ash ◽  
Heat Stable ◽  
Dry Ashing ◽  
Acid Reagent

Abstract A simple, rapid spectrophotometry method has been developed for direct determination of available phosphorus in fertilizers. Citrate and other organic materials are destroyed by dry ashing. The combined water and citrate extracts are diluted, a 5 ml aliquot is pipetted into a 25 ml Erlenmeyer flask, and 2 ml of ashing reagent (dilute HNO3, sucrose, and MgO) is added. During evaporation to dryness on a hot plate, nonorthophosphates are hydrolyzed to orthophosphates which react with Mg to form heat-stable compounds. During the subsequent ashing, phosphorus remains in the ortho form. Due to sucrose, the dry residue has a very porous structure and can be converted to a white ash in about 30 minutes in a pre-heated 550°C muffle. Color is developed with vanadomolybdic acid reagent. Absorbance is read on a spectrophotometer at 400 mμ.

Determination of Trichlorfon in Technical and Powder Formulations

1988 ◽  
Vol 71 (2) ◽  
pp. 317-320
Author(s):  
Stephen C Slahck
Keyword(s):  
Quality Control ◽  
Liquid Chromatography ◽  
Storage Stability ◽  
Direct Determination ◽  
Ion Pairing ◽  
Uv Detection ◽  
Powder Formulation ◽  
Technical Material ◽  
And Storage

Abstract A facile procedure is described for the determination of trichlorfon in technical material and an 80% powder formulation by using liquid chromatography with ion-pairing and UV detection. Liquid chromatography allows the direct determination of trichlorfon and detection of any dichlorvos present. This method is applicable to quality control and storage stability analyses and eliminates any need for derivatization to counter the thermal lability of trichlorfon. The average standard deviations for the technical and 80% formulation determinations were 0.51 and 0.37%, respectively.

An Improved Alkaline Citrate Method for Evaluation of Phosphorus in Fertilizers

1964 ◽  
Vol 47 (6) ◽  
pp. 1048-1054
Author(s):  
J A Brabson ◽  
W G Burch
Keyword(s):  
The Netherlands ◽  
Extraction Method ◽  
Phosphate Rock ◽  
Field Tests ◽  
Dicalcium Phosphate ◽  
Ammonium Citrate ◽  
Citrate Solution ◽  
Citrate Method ◽  
Insoluble Portion

Abstract The Netherlands alkaline ammonium citrate extraction method for the determination of available P2O5 was modified for routine use. The water-insoluble portion of the sample is extracted with the alkaline citrate solution for 2 hours in a shaking apparatus at 65°C. Dicalcium phosphate dissolves, but apatite, whether formed in processing (as in the ammoniation of superphosphate) or present as unreacted phosphate rock, does not dissolve. The results of the extraction method correlate well with those of field tests of the fertilizers.

Direct Determination of Potash in Fertilizers by Atomic Absorption Spectrophotometry

1973 ◽  
Vol 56 (1) ◽  
pp. 147-150
Author(s):  
Virginia A Thorpe
Keyword(s):  
Atomic Absorption ◽  
Direct Determination ◽  
Atomic Absorption Spectrophotometry ◽  
Available Phosphorus ◽  
Absorption Method ◽  
Atomic Absorption Method ◽  
Absorption Spectrophotometry ◽  
Scale Expansion

Abstract A rapid atomic absorption method is presented for the direct determination of potash in fertilizers, using the extract prepared for available phosphorus without dilution. By using the secondary potassium line and scale expansion, sensitive linear curves were obtained for 100–1000 ppm, covering K2O guarantees in all fertilizers.

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