Comparison of the TRAACS 800 with AOAC Methods for Calcium and Phosphorus in Feeds

1991 ◽  
Vol 74 (4) ◽  
pp. 619-624
Author(s):  
Anne Orcutt ◽  
Peter Kane ◽  
Sandra Imboden
Keyword(s):  
Standard Curve ◽  
Curve Fit ◽  
Significant Difference ◽  
Aoac Official ◽  
Calcium And Phosphorus ◽  
Automated Instruments ◽  
New Generation ◽  
Automated Methods ◽  
Concentration Levels

Abstract Existing automated methods for calcium and phosphorus In animal feeds have been upgraded to permit determination of protein, calcium, and phosphorus simultaneously from a single sample solution running on a new generation of automated instruments. Minor changes and improvements in chemistry are described, and results using the new method are compared to results using AOAC official atomic absorption (calcium) and gravimetric (phosphorus) methods. For calcium, Mests showed no significant difference at the P ≤ 0.01 level over a range of concentration levels from 0-25%. For phosphorus, Mests showed no significant difference at the P ≤ 0.01 level over concentration ranges of 0 - 2% and 2 - 6%. Significant differences did exist at a concentration range of 6-18%. The small existing bias In these ranges was shown to be due to irregularities In the phosphorus standard curve fit, caused by protein and/or calcium components in the combined standard solutions.

Microencapsulated antibodies in radioimmunoassay. II. Determination of free thyroxine.

1979 ◽  
Vol 25 (9) ◽  
pp. 1561-1563 ◽  
Author(s):  
E P Halpern ◽  
R W Bordens
Keyword(s):  
Serum Antibody ◽  
Free Thyroxine ◽  
Relative Molecular Mass ◽  
Displacement Reaction ◽  
Nylon Membrane ◽  
Mean Values ◽  
Standard Curve ◽  
Significant Difference ◽  
Control Samples

Abstract We describe a method for directly measuring free thyroxine in human serum. Antibody to thyroxine was encapsulated within a semipermeable nylon membrane that excludes substances of relative molecular mass greater than 20,000. The microencapsulated antibody was then presaturated with [125I]thyroxine. Serum incubated with the microcapsules initiated a displacement reaction between free thyroxine and [125I]thyroxine bound to the antibody. The displaced thyroxine was separated from the bound thyroxine by centrifugation and the concentration of free thyroxine determined from a standard curve prepared by use of known amounts of free thyroxine. The within-day coefficient of variation for two control samples was 8.8 and 6.8%; day-to-day precision for the same material was 12.5 and 13.5%. Lipemia, icterus, or hemoglobin had no adverse effect. Interlaboratory evaluation of the procedure revealed no significant difference in mean values for 20 speciments (p greater than 0.05).

scholarly journals Determination of Flavanones in Orange Juices Obtained from Different Sources by HPLC/DAD

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Lidércia C. R. Cerqueira e Silva ◽  
Jorge M. David ◽  
Rafael dos S. Q. Borges ◽  
Sérgio L. C. Ferreira ◽  
Juceni P. David ◽  
...  
Keyword(s):  
Principal Component ◽  
Liquid Extraction ◽  
Standard Curve ◽  
Liquid Liquid Extraction ◽  
Analysis Technique ◽  
External Standard ◽  
Different Sources ◽  
Principal Elements ◽  
Concentration Levels

Flavanones (hesperidin, naringenin, naringin, and poncirin) in industrial, hand-squeezed orange juices and from fresh-in-squeeze machines orange juices were determined by HPLC/DAD analysis using a previously described liquid-liquid extraction method. Method validation including the accuracy was performed by using recovery tests. Samples (36) collected from different Brazilian locations and brands were analyzed. Concentrations were determined using an external standard curve. The limits of detection (LOD) and the limits of quantification (LOQ) calculated were 0.0037, 1.87, 0.0147, and 0.0066 mg 100 g−1and 0.0089, 7.84, 0.0302, and 0.0200 mg 100 g−1for naringin, hesperidin, poncirin, and naringenin, respectively. The results demonstrated that hesperidin was present at the highest concentration levels, especially in the industrial orange juices. Its average content and concentration range were 69.85 and 18.80–139.00 mg 100 g−1. The other flavanones showed the lowest concentration levels. The average contents and concentration ranges found were 0.019, 0.01–0.30, and 0.12 and 0.1–0.17, 0.13, and 0.01–0.36 mg 100 g−1, respectively. The results were also evaluated using the principal component analysis (PCA) multivariate analysis technique which showed that poncirin, naringenin, and naringin were the principal elements that contributed to the variability in the sample concentrations.

scholarly journals Extension of AOAC Official Method 999.14 (Choline in Infant Formula and Milk) to the Determination of Choline in Dietary Supplements

2004 ◽  
Vol 87 (6) ◽  
pp. 1297-1304 ◽  
Author(s):  
Jeanne I Rader ◽  
Carol M Weaver ◽  
Mary W Trucksess
Keyword(s):  
Dietary Supplements ◽  
Dietary Supplement ◽  
Infant Formula ◽  
Sole Source ◽  
Official Method ◽  
Standard Curve ◽  
Liquid Products ◽  
Aoac Official ◽  
Aoac Official Method

Abstract AOAC Official Method 999.14 is applicable for the determination of choline in milk and infant formulas. To date, its use has not been extended beyond these matrixes. We modified Official Method 999.14 and applied it to the determination of choline in a range of choline-containing dietary supplements. Dietary supplement tablets, capsules, wafers, softgels, liquid products, and drink powders were included. We found that the standard curve could be extended to cover a wider range of choline concentrations and defined a procedure for the use of Norit for samples in which the vitamin C content was high enough to interfere with the analysis. Recoveries of choline added to infant formula powders and to representative dietary supplement tablets, capsules, powdered drink mix, and wafer products were 85–114%. The use of Norit during the procedure did not affect the recovery of choline added to infant formula powders or to dietary supplements. An alkaline digestion was included for use with a product containing lecithin as the sole source of choline.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

Features of phosphorus-calcium metabolism in children with neurogenic disorders of urination

2020 ◽  
Vol 24 (1) ◽  
pp. 45-50
Author(s):  
Yu. F. Lobanov ◽  
D. Y. Latyshev ◽  
Ya. F. Zverev ◽  
N. A. Tekuteva ◽  
N. M. Mikheeva
Keyword(s):  
Connective Tissue ◽  
Calcium Metabolism ◽  
Point System ◽  
Industry Standards ◽  
Muscular Dysfunction ◽  
Connective Tissue Dysplasia ◽  
Calcium And Phosphorus ◽  
Comparison Of The Results ◽  
Neurogenic Disorders

THE AIM: To study the characteristics of phosphorus-calcium metabolism in patients with neurogenic disorders of urination, taking into account the severity of the manifestations of connective tissue dysplasia. PATIENTS AND METHODS. The study included 90 children, including 60 children with neuro-muscular dysfunction of the bladder (NMDB) and 30 children with enuresis from the age of 5 to 15 years. The diagnosis was established based on a comprehensive examination and according to industry standards. Connective tissue dysplasia was diagnosed in children with the detection of 6 or more small external or visceral manifestations involving 3 or more organs from different systems. Assessment of the severity (severity) of connective tissue dysplasia was carried out according to the point system proposed by T.I. Kadurina et al. Each group was divided into subgroups depending on the severity of the manifestations of connective tissue dysplasia. The determination of the level of calcium and phosphorus in the blood and urine, as well as the calculation of the calcium-creatinine coefficient followed by a comparison of the results in these groups and subgroups. To assess the significance of differences, the Mann-Whitney test was calculated, p <0.05 was considered significant. RESULTS. he level of calcium and phosphorus in the urine was slightly higher in children with enuresis, especially in the morning portion of urine, where the concentration of calcium was 26% higher than in patients with NMDB. At the same time, the value of calcium /creatinine coefficient was significantly higher in the group of patients with enuresis and was 2 times higher than the normative indicators, which indicates the importance of hypercalciuria in the development of enuresis. СONCLUSION. According to the obtained data, the severity of calciuria, determined by the value of the calcium-creatinine coefficient, is significantly higher in patients with enuresis than with NMDB.

Laser optoacoustic detection of trace concentration levels of ethylene, vinylchloride, and styrene in the atmosphere

1989 ◽  
Vol 54 (10) ◽  
pp. 2667-2673 ◽  
Author(s):  
Vojtěch Steiner ◽  
Pavel Engst ◽  
Zdeněk Zelinger ◽  
Milan Horák
Keyword(s):  
Detection Limit ◽  
Emission Line ◽  
Laser Line ◽  
Laser Source ◽  
Trace Concentration ◽  
Selective Determination ◽  
Hygienic Standard ◽  
Trace Concentrations ◽  
Concentration Levels

The optoacoustic analyzer with a tunable CO2 laser source employed in the present work permits a selective determination of ethylene in trace concentrations higher than 5 ppb (=detection limit for the 10P(14) emission line of the CO2 laser, ν = 949.5 cm-1) and of vinylchloride higher than 42 ppb (= detection limit for the 10P(22) CO2 laser line, ν= 942.4 cm-1). this method covers for both compounds the concentration range corresponding to the hygienic standard. It can be also used for the determination of styrene vapour with concentrations higher than 1.5 ppm.

Adaptation of the AOAC Fluorine Method for Determining Fluoride in Fish Protein Concentrate

1970 ◽  
Vol 53 (1) ◽  
pp. 3-6
Author(s):  
R. Bruce Klemm ◽  
Mary E. Ambrose Klemm
Keyword(s):  
Steam Distillation ◽  
Silica Sand ◽  
Official Method ◽  
Protein Concentrate ◽  
Fish Protein ◽  
Direct Titration ◽  
Modified Method ◽  
Aoac Official ◽  
Aoac Official Method

Abstract The AOAC official method, 24.029–24.035, for the determination of fluorine in foods was modified slightly to o btain quantitative recoveries of fluorine from samples of fish protein concentrate (FPC). The most important alterations include the use of steam distillation, the addition of finely ground silica sand in the distillation, a decrease in the distillation temperature, and the utilization of direct titration. Recoveries of fluoride added to FPC before ashing, using this modified method, averaged 96.0 ± 3.0%. Our results are in agreement with those of several other analysts who used a variety of methods.

Spectrophotometric Determination of Raceophenidol in Feed at Very Low Levels

1968 ◽  
Vol 51 (4) ◽  
pp. 752-755
Author(s):  
Edward L Pratt ◽  
Morris E Auerbach
Keyword(s):  
Spectrophotometric Determination ◽  
Growth Promotion ◽  
Ultraviolet Spectrum ◽  
Average Value ◽  
Collaborative Studies ◽  
Low Levels ◽  
Concentration Levels

Abstract Raceophenidol in feed at concentration levels intended for growth promotion of poultry can be estimated by a curvature inversion measurement related to the ultraviolet spectrum of derived p-methylsulfonylbenzaldehyde. The drug can be accurately measured at the 0.0005% level. Collaborative studies on the method showed an average value of 94 ± 10% of claim. The method is recommended for adoption as official, first action.

scholarly journals Optimizing Manufacturing and Osseointegration of Ti6Al4V Implants through Precision Casting and Calcium and Phosphorus Ion Implantation? In Vivo Results of a Large-Scale Animal Trial

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1670 ◽  
Author(s):  
Wölfle-Roos JV ◽  
Katmer Amet B ◽  
Fiedler J ◽  
Michels H ◽  
Kappelt G ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Large Scale ◽  
In Vivo Studies ◽  
Control Group ◽  
Implant Surface ◽  
Precision Casting ◽  
Pull Out ◽  
Significant Difference ◽  
Calcium And Phosphorus

Background: Uncemented implants are still associated with several major challenges, especially with regard to their manufacturing and their osseointegration. In this study, a novel manufacturing technique—an optimized form of precision casting—and a novel surface modification to promote osseointegration—calcium and phosphorus ion implantation into the implant surface—were tested in vivo. Methods: Cylindrical Ti6Al4V implants were inserted bilaterally into the tibia of 110 rats. We compared two generations of cast Ti6Al4V implants (CAST 1st GEN, n = 22, and CAST 2nd GEN, n = 22) as well as cast 2nd GEN Ti6Al4V implants with calcium (CAST + CA, n = 22) and phosphorus (CAST + P, n = 22) ion implantation to standard machined Ti6Al4V implants (control, n = 22). After 4 and 12 weeks, maximal pull-out force and bone-to-implant contact rate (BIC) were measured and compared between all five groups. Results: There was no significant difference between all five groups after 4 weeks or 12 weeks with regard to pull-out force (p > 0.05, Kruskal Wallis test). Histomorphometric analysis showed no significant difference of BIC after 4 weeks (p > 0.05, Kruskal–Wallis test), whereas there was a trend towards a higher BIC in the CAST + P group (54.8% ± 15.2%), especially compared to the control group (38.6% ± 12.8%) after 12 weeks (p = 0.053, Kruskal–Wallis test). Conclusion: In this study, we found no indication of inferiority of Ti6Al4V implants cast with the optimized centrifugal precision casting technique of the second generation compared to standard Ti6Al4V implants. As the employed manufacturing process holds considerable economic potential, mainly due to a significantly decreased material demand per implant by casting near net-shape instead of milling away most of the starting ingot, its application in manufacturing uncemented implants seems promising. However, no significant advantages of calcium or phosphorus ion implantation could be observed in this study. Due to the promising results of ion implantation in previous in vitro and in vivo studies, further in vivo studies with different ion implantation conditions should be considered.

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