Method For Determination Of Phosphorus Research Articles

Validation of a small-scale method for determination of phosphorus in meat and meat products by molecular absorption spectroscopy

The purpose of this study was to evaluate the applicability of an alternative analytical technique to the reference method for phosphorus detection in meat and meat products established by ISO 2294:1974, revised by ISO 23776:2021. When an analytical method is modified or a new one is developed and implemented, it should be validated before being accepted for routine determinations. Furthermore, it is necessary to demonstrate that the new or alternative method has good performance characteristics in comparison with the reference method. Therefore, a comparison of the performance of the alternative and the reference method should be made. In the present study, a statistical evaluation of the calibration model of the alternative method was made with data from interlaboratory studies made in five consecutive years using fifty analyses of meat and meat products. The statistical parameters evaluated over time for the calibration curve were the y-intercept and slope; correlation and linearity; analytical limits: detection and quantification; working range; and accuracy (precision and trueness). In the interlaboratory tests, the results obtained by the alternative analytical method were compared with those obtained by the reference method, and their performance in these tests was also evaluated. The results obtained by the alternative method indicated better accuracy than the reference method due to lower relative errors, more precision, and a good trueness evaluation through lower absolute values of the z-score. The study demonstrated that the phosphorus alternative method is applicable for the determination of total phosphorus in the matrix of meat and meat products.

РАЗРАБОТКА МЕТОДА ОПРЕДЕЛЕНИЯ СОДЕРЖАНИЯ ФОСФОРА В ПРИПОЕ ВПр18

РАЗРАБОТКА МЕТОДА ОПРЕДЕЛЕНИЯ СОДЕРЖАНИЯ ФОСФОРА В ПРИПОЕ ВПр18

A Simple and Fast Method for Determination of Phosphorus in Fish Diets and Faeces Used in Animal Nutritional Studies

The optimization and validation of a simple and fast analytical method for the determination of phosphorus in fish diets and faeces used in animal nutrition studies are shown in this paper, starting with the validation of a pre-optimized digestion procedure for biological samples, choice of the best chemical modifier and the minimal sample amounts. The digestion procedure consisted of an acid dissolution of a minimal of 100 mg of dry sample in a domestic microwave system using Parr Teflon bombs at high pressure. The P levels were determined by atomic absorption spectrometry with electrothermal atomisation, using an absorbance of 213.6 nm, a slit width of 1.0 nm, a current lamp of 20 mA and a deuterium lamp for background correction. Different furnace temperature programmes were used, and a final temperature programme was optimized. The optimization stages suggested the use of a 1,000 μg/ml La solution as chemical modifier and 1,600 and 2,700 °C as, respectively, the best pyrolysis and atomisation temperatures. The optimized analytical method was applied to different types of fish diets and faeces, and the percentages of recovery of P in spiked samples were, respectively, 94 ± 11% (n = 3) and 100 ± 12% (n = 3). The detection limit was 0.15 mg P/g of dry sample. The optimized methodology is simpler, faster and has less sample mass consumption than normally used colorimetric methods.

Simple and rapid determination of phosphorus in meat samples by WD-XRF method

The wavelength dispersive X-ray fluorescence (WD-XRF) method for phosphorus determination in meat samples has been described. The effects of sample pretreatment on the XRF analysis have been discussed. The phosphorus content determined in meat samples ranged from 603 ± 6 to 613 ± 19 mg P/100g dry mass (d.m.), depending on the sample preparation technique. The meat samples spiked with phosphates have been used for the calibration procedure. The accuracy was determined against a number of certified reference materials (SMRD 2000, RF 8414, NIST-1568A, and NIST-1549), and recovery was assayed using the standard addition procedure. The proposed method has been compared with the standard spectrophotometric method (PN-ISO 13730, 1999) of total phosphorus determination. The sample pretreatment procedure has been reduced to minimum the presented results suggest the WD-XRF method can be an alternative to the spectrophotometric analysis.

Comparison of different methods for determination of phosphorus in calcium chloride extracts for prediction of availability to plants

Abstract Soil samples, dried and in field moisture condition, respectively, were extracted by 0.01M calcium chloride (CaCl2) at two different soil:extractant ratios (1:2 and 1:10), and analysed by inductively coupled plasma emission spectrometry (ICP), by ion Chromatograph, and by two different molybdenum blue methods for content of phosphorus (P). There was a good relationship between the methods, although the different methods gave quite different P values. Phosphorus detected by the molybdenum blue methods included not only orthophosphates, and the values were influenced by method‐dependent factors like effect of temperature. The difference is important when studying the complex of P cycle in soil and its plant availability and stresses the need for a reliable method of detecting low amounts of orthophosphates in soil extracts. Plant samples, collected at the same times as the soil samples, were digested in concentrated nitric acid (HNO3) and the P content determined by ICP. Linear regressions were per...

Comparison of sample preparation methods for the spectrophotometric determination of phosphorus in soil and coal fly ash

Three different sample preparations were evaluated for determining phosphorus spectrophotometrically in two different matrices, soil and coal fly ash. The absorbance of the blue molybdenum complex was measured at a wavelength of 804 nm with a 1 cm cell on a spectrophotometer. One digestion method involved an HCl leaching and the other two methods involved a lithium metaborate fusion to which was added an additional HF digestion step in the third digestion method. The HCl leaching method is not recommended for either matrix. The faster lithium metaborate fusion method is recommended for soils and fly ash.

Potential errors in the use of the Murphy and Riley method for determination of phosphorus in soil extracts

Abstract The Murphy and Riley method for phosphorus (P) determination is used with almost all commonly used soil P extractants, but few tests for the effects of extractants itself on the indicator species have been reported. In practice, it is important to know the period of stability of the indicator species and the range of P and extractant concentrations that produce reliable results. In this study, a series of tests was conducted over a range of extract volumes to determine indicator species stability and to identify factors affecting it. Three soil P extradants (Mehlich‐3, Bray‐I, and Modified Truog) and three soils were tested at different levels of extract volume, solution pH, and P concentration. In our tests, Bray‐I and Modified Truog did not interfere with the stability of the indicator species under conditions commonly used for soil P determinations. Mehlich‐3 caused fading of the blue color at low P concentrations and precipitation of a blue compound at high P concentrations. This instability ...

Amplification method for the spectrophotometric determination of phosphorus

An amplification method with ion-exchange pre-separation for the spectrophotometric phosphorus determination in various alloys is described. Phosphorus is converted into molybdophosphoric acid, separated by selective extraction and back-extracted into the aqueous phase. The molybdenum is liberated by alkaline decomposition of the heteropoly acid. The spectrophotometric measurement is based on the reaction of molybdenum(VI) with 2,2′-biquinoxalyl. High molar absorptivity of 1,1′-dihydro-2,2′-biquinoxalylene (e=3.3 · 104 L mol−1 cm−1) and the twelve-fold amplification guarantee high precision and makes the determination of phosphorus in the 1–6 μg level possible.

Sulfuric Acid/Hydrogen Peroxide Digestion and Colorimetric Determination of Phosphorus in Meat and Meat Products: Collaborative Study

Abstract Seven laboratories participated In a collaborative study of a method for determination of phosphorus in meat and meat products. Samples are digested In sulfuric acid and hydrogen peroxide; digestion Is complete In approximately 10 mln. Phosphorus Is determined by colorimetric analysis of a dilute aliquot of the sample digest. The collaborators analyzed 3 sets of blind duplicate samples from each of 6 classes of meat (U.S. Department of Agriculture classifications): smoked ham, water-added ham, canned ham, pork sausage, cooked sausage, and hamburger. The calibration curve was linear over the range of standard solutions prepared (phosphorus levels from 0.05 to 1.00%); levels in the collaborative study samples ranged from 0.10 to 0.30%. Standard deviations for repeatability (sr) and reproducibility (sR) ranged from 0.004 to 0.012 and 0.007 to 0.014, respectively. Corresponding relative standard deviations (RSDr and RSDR, respectively) ranged from 1.70 to 7.28% and 3.50 to 9.87%. Six laboratories analyzed samples by both the proposed method and AOAC method 24.016 (14th Ed.). One laboratory reported results by the proposed method only. Statistical evaluations Indicated no significant difference between the 2 methods. The method has been adopted official first action by AOAC.

Indirect atomic-absorption spectrophotometric determination of phosphorus in steel by use of the bismuth phosphomolybdate complex

An indirect method for determination of phosphorus by atomic-absorption spectrophotometry has been developed, based on formation of the bismuthophosphomolybdate complex and its extraction by methyl isobutyl ketone. Bismuth is determined in the extract and correlated with the phosphorus content. The method is applicable to different kinds of steel.

Speciative determination of phosphorus in environmental water by the isotope exchange method

An isotope exchange method for the speciative determination of phosphorus (PO43−, PO33− and total P) in natural water samples is proposed by using the exchange system of moly bdophosphate in the aqueous phase and tetraphenylarsonium molybdophosophate in the organic phase. In this exchange system, only PO43− exchanges and is determined. When the sample water is treated with Br2 water in advance, the amount of PO43−+PO33− can be obtained. When the sample is treated with H2SO4 and HNO3, then the amount of total P can be determined.

Determination of phosphorus and tungsten in heteropoly acids by EDTA-titration

Previous methods for the titrimetric determination of phosphorus and tungsten with EDTA are found to be unsatisfactory for heteropoly acids. Successful modifications of the procedures are described.

Reaction-rate method for the determination of phosphorus in agricultural products

A new automated reaction-rate method for the quantitative determination of phosphorus in grains and feeds is presented. The chemical methodology has been investigated, resulting in a high analytical throughput with precise, accurate results. The phosphomolybdenum blue reaction is used for the reaction-rate determination. After digestion of the samples by the official AOAC block digestion procedure, automated instrumentation is used for precise and rapid combination of the reactants and transfer of the mixed solution to an automated spectrophotometer. The rate of formation of the product during 5 sec is automatically determined and compared with rates obtained for phosphorus standards to determine the phosphorus content of the sample. Relative standard deviations of about 0.3% are obtained and results for determinations of phosphorus in grains and feeds are accurate as indicated by comparison with the average obtained by all laboratories participating in the AAFCO check sample programme.

Determination of phosphorus in copper-phosphorus alloys, by GLC technique

A simple, sensitive, accurate and rapid gas chromatographic method for the quantitative determination of phosphorus in copper-phosphorus alloys is described. The method is based on the chlorination of the sample with carbon tetrachloride in a sealed glass capsule at 550°C. The volatile products are introduced into the gas chromatograph after crushing the capsule in a special device.

Flameless atomic-absorption determination of phosphorus using ZrC coated graphite atomizer tubes

A flameless atomic-absorption method for determination of phosphorus is developed, employing zirconium treated graphite tubes. The great improvement of the sensitivity with these tubes eliminates the necessity of adding La(NO3)3. The sensitivity does not vary from tube to tube and its maximal value is attained within the first 2–3 firings. The atomization signal is practically the same within the range of 2,600–2,800° C when the rise of the temperature is high (> 1,500° C/s). The best signal to noise ratio is obtained at 2,600° C. The detection limit is 0.05 ppm with injection of 50 μl. The method is applied to the analysis of a standard steel sample.

Improvement of Baginski's method for phosphorus determination

Improvement of Baginski's method for phosphorus determination

Indirect ultraviolet spectrophotometric and atomic absorption spectrometric methods for determination of phosphorus and silicon by heteropoly chemistry of molybdate

Indirect ultraviolet spectrophotometric and atomic absorption spectrometric methods for determination of phosphorus and silicon by heteropoly chemistry of molybdate

Rapid Combustion Method for Determination of Phosphorus in Petroleum Products

Rapid Combustion Method for Determination of Phosphorus in Petroleum Products

Simulataneous determination of silicon and phosphorus in the presence of each other

Summary An accurate and reproducible colorimetric method for the simultaneous determination of phosphorus and silicon in the presence of each other is reported. The method involves the selective extraction of phospho-heteropoly blue by diethyl ether.

Rapid Digestion Method for Determination of Phosphorus

Rapid Digestion Method for Determination of Phosphorus