Chemical Determination of Niacinamide in Multivitamin Preparations

1968 ◽  
Vol 51 (4) ◽  
pp. 828-834
Author(s):  
Omer Pelletier
Keyword(s):  
Coefficient Of Variation ◽  
Microbiological Method ◽  
Chemical Methods ◽  
Mean Values ◽  
The Third ◽  
Collaborative Studies ◽  
Chemical Determination ◽  
Aoac Method ◽  
The Mean

Abstract The AOAC method and the Pelletier and Campbell method for the assay of niacinamide in multivitamin preparations were compared in two collaborative studies. In the first study, three multivitamin sirup preparations were analyzed by six laboratories; the proposed method gave higher results for two preparations but lower results for the third. In the second study, four types of multivitamin preparations were analyzed; twelve laboratories reported on the chemical methods and three laboratories on the microbiological method. There was no difference in the mean values for two types of samples, but one sample of multivitamin tablets yielded mean values about 5% lower by the proposed method, suggesting the presence of a trace of niacin; with a multivitamin and mineral sirup the proposed method gave values about 6% higher than the AOAC method and 3% lower than the microbiological assay. The coefficient of variation for any sample in any laboratory by the AOAC method was about 14% in the first study and 1 1% in the second study; by the proposed method it was 4 and 9% in the same respective studies. It is recommended that the present AOAC method be modified by adjusting the pH of sample hydrolysates in the range of 2.5—4.5 instead of 7—9 to reduce the absorhance of the blanks, and that the method of Pelletier and Campbell be adopted as official, first action.

scholarly journals Determination of Moisture in Raisins

1997 ◽  
Vol 80 (2) ◽  
pp. 439-440 ◽  
Author(s):  
Kostanttne Katsaboxakis
Keyword(s):  
Diatomaceous Earth ◽  
Steam Bath ◽  
New Method ◽  
Constant Weight ◽  
Mean Values ◽  
Carcinogenic Substance ◽  
Aoac Method ◽  
The Mean

Abstract The determination of moisture in Soultanina raisins by drying in a steam bath with diatomaceous earth to constant weight (about 70 min) was compared with the official AOAC Method 22.013, which uses asbestos and requires 6 h of drying at 70°C under <100 mm Hg. Five different samples (moisture 11-22%) were analyzed by the 2 methods; the mean values of 9 replications did not differ significantly. The new method is rapid and simple, and it eliminates asbestos, a known carcinogenic substance, from the determination.

scholarly journals Ultrasound Determination of Gestational Age Using Placental Thickness in Female Dogs: An Experimental Study

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
André Luiz Louzada Maldonado ◽  
Edward Araujo Júnior ◽  
Débora Sartori Mendonça ◽  
Luciano Marcondes Machado Nardozza ◽  
Antonio Fernandes Moron ◽  
...  
Keyword(s):  
Experimental Study ◽  
Body Weight ◽  
Gestational Age ◽  
Thickness Measurement ◽  
Mean Values ◽  
The Third ◽  
Large Size ◽  
The Mean ◽  
Placental Thickness

Objective. To verify if the placental thickness allows determining the gestational age, evaluating the correlation between the referred gestational age with the studied one, and the accuracy of the placental thickness measurement (biometry) with fetal morphologic parameters in bitches.Methods. The placental thickness of 336 bitches of diverse breeds was evaluated. Bitches were divided in three groups by body weight: small, medium, and big large size. The gestations pregnancies were evaluated by ultrasound from the third week of gestation. An analysis was performed between the mean values of the gestational age obtained of placental thickness by adjustment of curves and the reported gestational age. Student'st-test was applied to compare the mean of reported and placental thickness gestational age. Significance was defined asP<0.05.Results. A positive and statistically significant correlation exists between the placental thickness and gestational age. The expression that presents the best correlation coefficient and explanation was thickness of placenta = 0.021xgestational age −0.314.Conclusion. It is possible to determine the gestational age in relation to the placental thickness measured by ultrasound in bitches with a satisfactory accuracy in relation to fetal morphologic parameters as gestational vesicle, ribs, or kidneys.

Gamma-Ray Spectroscopic Determination of Iodine-131 and Cesium-137 in Foods: Two Collaborative Studies

1989 ◽  
Vol 72 (4) ◽  
pp. 667-669
Author(s):  
Edmond J Baratta ◽  
David G Easterly
Keyword(s):  
Gamma Ray ◽  
Food Sample ◽  
Spectroscopic Determination ◽  
Collaborative Studies ◽  
Cesium 137 ◽  
Aoac Method ◽  
Iodine 131 ◽  
The Mean ◽  
Standard Deviations

Abstract The AOAC method for iodine-131, cesium-137, and barium-140 in milk by gamma-ray spectroscopy (48.025-48.029) was extended to include other foods for the radionuclides iodine-131 and cesium-137. Two collaborative studies were performed to validate this extension. In the first study, a food sample containing 119 pCi ,3,I/kg and 53 pCi 137Cs/kg was sent to each of 45 laboratories for triplicate analyses. For 25 responses, the mean of the reported values was 123.8 pCi/kg for iodine-131, and for 27 responses, the mean was 53.4 pCi/kg for cesium-137. Repeatability (within-laboratory) standard deviations (sr) for iodine-131 and cesium-137 were 4.6 and 3.7 pCi/kg, respectively. Reproducibility (among-laboratories) standard deviations (sR) for iodine-131 and cesium-137 were 12.1 and 6.0 pCi/kg, respectively. In the second study, a food sample containing 25 pCi 13,I/kg and 27 pCi 137Cs/kg was sent to each of 54 laboratories for triplicate analyses. For 21 responses, the mean of the reported values was 25.0 pCi/kg for iodine-131, and for 19 responses, the mean was 28.9 pCi/kg for cesium-137. sr Values were 4.0 and 1.6 pCi/kg for iodine-131 and cesium-137, respectively, and SR values were 5.0 and 2.8 pCi/kg, respectively. The method extension was adopted official first action.

scholarly journals The difference-periodogram—a method for the rapid determination of short periodicities

1924 ◽  
Vol 105 (731) ◽  
pp. 346-359 ◽  
Keyword(s):  
Rapid Determination ◽  
Mean Value ◽  
Half Cycle ◽  
Mean Values ◽  
The Third ◽  
The Mean ◽  
The Difference ◽  
Periodic Components ◽  
Similar Phase

The examination of a long series of observations in the search for periodicities by harmonic analysis is a tedious process. The method outlined below, although rough, has the merit of being much more rapid in its application, and has been found useful in the preliminary exploration of long meteorological records of periodic or quasi-periodic components. It is also useful in the study of periodicities of intermittent recurrence or variable length. The basis of the method is the division of a series of observations into series which are nearly, but not quite, equal, to half the length of the suspected periodicity. If each section were exactly half the periodicity the first, third, fifth, etc., sections would all occur in the same position relatively to the periodic curve, while the second, fourth, sixth, etc., would occur a half-cycle away. If each section is slightly less than half the length of the periodicity, then the third and so on, until after a certain interval the n th section occurs at a similar phase to the first. The number of sections required to bring this about depends on the relation between their length and the length of the periodicity. If the sections selected had been slightly longer than half the periodicity, the phase would advance somewhat between the first and third sections, and so on until the cycle was repeated. Thus by plotting the mean values of all the odd sections and drawing a curve through them we could obtain an idea of the length of the underlying periodicity. The even sections could be plotted in the same way, and if the series of observations were completely be the reverse of each other. Thus by substituting for the mean value of each section its difference from the mean of the whole series, and reversing the sign of all the even sections, we can bring the latter into line with the odd sections and draw a single curve representing all the observations.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

SENSITIVE AND SPECIFIC ENZYME-LINKED IMMUNOSORBENT ASSAY FOR UROKINASE-TYPE PLASMINOGEN ACTIVATOR IN HUMAN PLASMA

1987 ◽  
Author(s):  
J Grøndahl-HANSEN ◽  
N Agerlin ◽  
L S Nielsen ◽  
K Danø
Keyword(s):  
Plasminogen Activator ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mean Values ◽  
Amino Terminal ◽  
Type Plasminogen Activator ◽  
Healthy Donors ◽  
Urokinase Type Plasminogen Activator ◽  
The Mean

An enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of human urokinase-type plasminogen activator (u-PA) in plasma and serum. Microtiter plates were coated with a monoclonal antibody and incubated with standard or sample. Bound u-PA was quantitated with polyclonal antibodies conjugated with biotin, followed by avidin-peroxidase. The assay was 10-fold as sensitive as other previously reported ELISAs, the detection limit being approximately 1 pg of u-PA in a volume of 100 μl with a linear dose-response up to 15 pg of u-PA. The assay detected active u-PA and its inactive proenzyme form equally well and the recovery of both forms was higher than 90% in plasma. A variety of structurally related proteins, including t-PA, were tested, but no reaction with proteins other than u-PA and its amino-terminal degradation product were observed. The intra-assay and inter-assay coefficients of variation for determination of u-PA in plasma were 7.6% and 8.4%, respectively. The assay was equally applicable to serum. The values obtained with plasma and serum were similar, and the results were not affected by small variations in the preparation of the samples. The ELISA was used to measure the concentration of u-PA in plasma from 34 healthy donors. The mean values for u-PA in plasma from healthy donors was 1.1 ng/ml ± 0.3 ng/ml (SD) (range 0.6 - 1.5 ng/ml). No significant differences were found between men and women and no correlation between u-PA concentration and age could be demonstrated.The mean u-PA concentration in plasma from healthy donors obtained in this study is substantially lower than that reported by others. This might be due to different methods of determination of the protein content of the standard preparations or to differences in the specificity of the assays.

scholarly journals pH of exudate test in the physiological quality of crambe seeds

2016 ◽  
Vol 46 (6) ◽  
pp. 1014-1018 ◽  
Author(s):  
Charline Zaratin Alves ◽  
Lennis Afraire Rodrigues ◽  
Carlos Henrique Queiroz Rego ◽  
Josué Bispo da Silva
Keyword(s):  
Pearson Correlation ◽  
Raw Material ◽  
Mean Values ◽  
Tukey Test ◽  
Physiological Quality ◽  
The Subject ◽  
The Mean ◽  
C 30

ABSTRACT: Crambe is a rapeseed with high oil content and can be used as a winter cover or as a source of raw material for the production of biodiesel, however espite the growing interest in the culture, research on the subject is still incipient, especially concerning the seed production and analysis technology. The purpose of this study is to evaluate the physiological quality of crambe seeds, 'FMS Brilhante' cultivar, by testing the pH of exudate. Five seed lots were submitted to the determination of water content and the tests of germination and vigor (first count, emergence and tetrazolium). In the conduction of pH exudate test, temperatures (25 and 30oC), and periods of seed imbibition in water (15, 30 and 45 minutes) were tested. The experiment was conducted in a completely randomized manner, with four replicates, and the mean values were compared by the Tukey test at 5% probability; Pearson correlation between the pH of the exudate and initial tests was also made. Testing the pH of exudate is promising for separating lots of crambe seeds and the following combinations of 25°C/30 minutes or 30°C/45 minutes can be used.

The Determination of the Probabilistic Properties of Velocities and Accelerations in Kinematic Chains With Uncertainty

1989 ◽  
Author(s):  
S. J. Lee ◽  
B. J. Gilmore
Keyword(s):  
Effective Length ◽  
Radial Clearance ◽  
Probabilistic Design ◽  
Link Length ◽  
Mean Values ◽  
Kinematic Chains ◽  
Analysis Package ◽  
The Mean ◽  
Linkage Model

Abstract A probabilistic model and methods to determine the means and variances of the velocity and acceleration of stochastically-defined planar pin jointed kinematic chains are presented. The presented model considers the effect of tolerances on link length and radial clearance and uncertainty of pin location as a net effect on the link’s effective length. The determination of the mean values and variances of the output variables requires the calculation of sensitivities of secondary variables with respect to the random variables. It is shown that this computation is straightforward and can be accomplished by a conventional kinematic analysis package. Thus, the concepts of tolerance and clearance have been captured by the model and analysis. The only input data is the nominal linkage model and statistical information. The “effective link length” model is shown to be applicable to both analytical solution and Monte Carlo simulation. The results from both methods are compared. This paper solves the higher-order kinematics problem for the probabilistic design analysis of stochastically defined mechanisms.

Collaborative Study of the Gas-Liquid Chromatographic Assay for Vitamin E

1972 ◽  
Vol 55 (6) ◽  
pp. 1211-1218
Author(s):  
B C Rudy ◽  
F P Mahn ◽  
B Z Senkowski ◽  
A J Sheppard ◽  
W D Hubbard
Keyword(s):  
Vitamin E ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Tocopheryl Acetate ◽  
Pharmaceutical Manufacturers ◽  
Collaborative Studies ◽  
Soft Gelatin Capsules ◽  
Acid Succinate ◽  
The Mean ◽  
Liquid Chromatographic

Abstract A collaborative study for the analysis of vitamin E in multivitamin tablets was conducted and the method was subsequently approved as official first action by the AOAC. Additional data were obtained by an extensive collaborative study sponsored by the Pharmaceutical Manufacturers Association, which verified the usefulness of GLC for the assay of α-tocopherol, α-tocopheryl acetate, and α-tocopheryI acid succinate. The mean coefficient of variation obtained from the 8 participating laboratories for duplicate samples, duplicate injections, was ±2.04, 1.75, and 2.71%, respectively. Further collaborative studies were conducted on samples of mixed tocopherol concentrate, multivitamin tablets, and multivitamin soft gelatin capsules. The mean coefficient of variation obtained from 13 collaborators was in the range of ±5%. The accumulated data demonstrate the utility of this technique for improved specificity and reliability of the analysis of vitamin E.

Colorimetric Method for Rapid Determination of Serum Arginase

1967 ◽  
Vol 13 (10) ◽  
pp. 900-908 ◽  
Author(s):  
Brigitta Mellerup
Keyword(s):  
Rapid Determination ◽  
Colorimetric Method ◽  
Normal Range ◽  
Clinical Routine ◽  
Mean Values ◽  
Enzymatic Formation ◽  
Significant Difference ◽  
The Mean ◽  
Normal Men

Abstract A method for the determination of serum arginase is given which combines the enzymatic formation of urea with the sensitive method of Coulombe (1) for measuring this substance. This procedure allows more accurate determinations in the normal range than do previous methods described and is convenient for clinical routine. Significant difference is found between the mean values of normal men and women, 3.9 units/L. for the former and 2.9 units/L. for the latter.

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