Pyridine Extraction Method for Determination of Bacitracin in Feeds: Collaborative Evaluation

1979 ◽  
Vol 62 (3) ◽  
pp. 662-670
Author(s):  
Hussein S Ragheb
Keyword(s):  
High Temperature ◽  
Extraction Method ◽  
Main Difficulty ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
The Difference ◽  
Zinc Bacitracin ◽  
Collaborative Evaluation

Abstract Seventeen laboratories evaluated the pyridine extraction method and neomycin-sensitized agar for the determination of zinc and MD bacitracin in swine and broiler rations at 10 and 100 g/ton. The method was also applied to the analysis of 2 premixes labeled 50 g/lb (MD bacitracin) and 40 g/lb (zinc bacitracin). Bacitracin activity was determined on each of 2 days with 2 dilutions on each day. No significant difference was found between dilutions within a day or between days for each sample. The type of bacitracin or type of feed did not significantly affect results. The difference in results between MD and zinc bacitracin in premixes approached significance. The large coefficients of variation for premixes (ca 13%) and complete feeds (ca 15–30%) indicate operational problems. The main difficulty was evaporation of pyridine. Some laboratories were not able to evaporate it completely, whereas others lost bacitracin activity, probably due to high temperature of drying. The pyridine extraction method as in 42.200 and 42.204 should be discontinued.

scholarly journals HemoCue against Coulter LH-750 in the estimation of hemoglobin levels of blood donors in mobile collection settings: a comparative study

2018 ◽  
Vol 27 (4) ◽  
pp. 250-5
Author(s):  
Sultan A.M. Saghir ◽  
Amer A. Almaiman ◽  
Aishah K.A. Shatar ◽  
Norris Naim ◽  
Huda S. Baqir
Keyword(s):  
Blood Donors ◽  
Reference Method ◽  
Cross Sectional Study ◽  
Outpatient Setting ◽  
Concordance Correlation ◽  
Cross Sectional ◽  
New Device ◽  
Coefficients Of Variation ◽  
Significant Difference

Background: The fast and outpatient setting for a determination of the hemoglobin (Hb) level is a well-recognized prerequisite to detect anemia in blood donors. This study aimed to evaluate the performance of the HemoCue methods (HemoCue B-Hb and HemoCue-301) against Coulter LH-750 as a reference method for Hb determination.Methods: This study was an experimental cross-sectional study. It includes 455 blood samples that were collected from volunteer blood donors between January 15, 2010 and February 15, 2011. The performance of the three methods and their comparisons were assessed using the analysis of coefficients of variation (CV), linear regression, and mean difference. Correlation coefficient and Bland–Altman plots were drawn to compare the two HemoCue measurements and the automated cell analyzer against each other and to evaluate their results. The Hb concentrations were compared using the concordance correlation coefficient.Results: The findings exhibited that the CV for the three methods Coulter LH-750, HemoCue B-Hb, and HemoCue-301 were 0.60%, 0.72%, and 0.92%, respectively. A statistically significant difference was observed between the means of the Hb measurements for the three methods (p<0.001). The HemoCue B-Hb and HemoCue-301 methods showed the best agreement, and the Coulter LH-750 method gave a lower Hb value compared with the two HemoCue methods. The results showed a positive correlation of HemoCue Hb results compared with the reference method.Conclusion: All three methods provide a good agreement for Hb determination. The new device HemoCue-301 was found to be more accurate compared with HemoCue B-Hb and Coulter LH-750.

scholarly journals Pengaruh Penerapan Model Pembelajaran Kooperatif Tipe Course Review Horay (CRH) Terhadap Keaktifan Belajar dan Hasil Belajar Ekonomi

2019 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Aisyah Aisyah
Keyword(s):  
Learning Outcomes ◽  
Sampling Method ◽  
Learning Model ◽  
Positive Influence ◽  
Learning Activity ◽  
Economic Study ◽  
Purposive Sampling ◽  
Significant Difference ◽  
The Difference

This research is experimental research on students class XI of MIPA in SMA Negeri 3 Purwokerto. This research takes the title of "The Influence of the Application of the Cooperative Learning Model Type Course Review Horay (CRH) Against the Liveliness of learning and the Results of the Economic Study (study on the Grade XI MIPA in SMA Negeri 3 Purwokerto)". The purpose of this research is to know the difference in learning outcomes and learning activity between the learning model Course Review Horay (CRH) with conventional learning model, to know the influence of learning model Course Review Horay (CRH) against the learning outcomes and learning activity, as well as to know the influence of the liveliness of the learning results of learning. The population of this research is the grade XI MIPA in SMA Negeri 3 Purwokerto. The number of samples taken in this study is 72 i.e. 2 Class XI of MIPA which each class amounted to 36 students. Purposive Sampling Method used in the determination of the sample. Based on the results of the research and the anallisis data indicate that (1) there is a significant difference between the model of learning learning activeness cooperative Course Review Horay (CRH) and conventional learning model on economics. (2) there are significant differences between the learning outcomes learning model cooperative Course Review Horay (CRH) and conventional learning model on economi. (3) there is a positive influence learning model cooperative Course Review Horay (CRH) against the liveliness of the study on economic. (4) there is a positive influence learning model cooperative Course Review Horay (CRH) against the results of the study on economic. (5) there is no positive influence between the liveliness of student learning against the results of the study on economic. Penelitian ini adalah penelitian eksperimen pada siswa kelas XI MIPA di SMA Negeri 3 Purwokerto. Penelitian ini mengambil judul “Pengaruh Penerapan Model Pembelajaran Kooperatif Tipe Course Review Horay (CRH) terhadap Keaktifan Belajar dan Hasil Belajar Ekonomi (Studi pada Siswa Kelas XI MIPA di SMA Negeri 3 Purwokerto)”.        Tujuan dari penelitian ini adalah untuk mengetahui perbedaan keaktifan belajar dan hasil belajar antara model pembelajaran Course Review Horay (CRH) dengan model pembelajaran konvensional, untuk mengetahui pengaruh model pembelajaran Course Review Horay (CRH) terhadap keaktifan belajar dan hasil belajar, serta untuk mengetahui pengaruh keaktifan belajar terhadap hasil belajar. Populasi penelitian ini adalah siswa kelas XI MIPA di SMA Negeri 3 Purwokerto. Jumlah sample yang diambil dalam penelitian ini adalah 72 yaitu 2 kelas XI MIPA yang masing-masing kelas berjumlah 36 siswa. Purposive Sampling Method digunakan dalam penentuan sample. Berdasarkan hasil penelitian dan anallisis data menunjukkan bahwa (1) Terdapat perbedaan signifikan keaktifan belajar antara model pembelajaran kooperatif Course Review Horay (CRH) dengan model pembelajaran konvensional pada mata pelajaran ekonomi. (2) Terdapat perbedaan signifikan hasil belajar antara model pembelajaran kooperatif Course Review Horay (CRH)  dengan model pembelajaran konvensional pada mata pelajaran ekonomi. (3) Terdapat pengaruh positif model pembelajaran kooperatif Course Review Horay (CRH)  terhadap keaktifan belajar pada mata pelajaran ekonomi. (4) Terdapat pengaruh positif model pembelajaran kooperatif Course Review Horay (CRH)  terhadap hasil belajar pada mata pelajaran ekonomi. (5) Tidak terdapat pengaruh positif antara keaktifan belajar siswa terhadap hasil belajar pada mata pelajaran ekonomi.  

scholarly journals Study on the Distribution Characteristics and Influencing Factors of Homocysteine in the Physical Examination Population

2021 ◽  
Author(s):  
Fang Bao ◽  
Ming Cui ◽  
Xiuying Shi ◽  
Shaoqing Ju ◽  
Hui Cong
Keyword(s):  
Blood Pressure ◽  
Physical Examination ◽  
Large Scale ◽  
Kidney Injury ◽  
Scientific Basis ◽  
Cerebrovascular Diseases ◽  
Health Examination ◽  
Significant Difference ◽  
The Difference

Abstract Background: Homocysteine (Hcy) is considered to be an independent risk factor for cardiovascular and cerebrovascular diseases. No study has evaluated the distribution of Hcy on a large-scale health examination. Accordingly, this study aimed to investigate the level and distribution of Hcy in the healthy physical examination population and the correlation with other biomarkers, and analyzed for cardiovascular and other diseases. The prevention provides an important scientific basis.Methods: From February 2017 to April 2020, 8063 medical examination populations were selected for analysis. Determination of serum Hcy, TC, TG, LDL-c, HDL-c, ALT, ALP, γ-GT, TBIL, GLU, urea, Cr, UA and related metabolic risk factors. According to the multivariate regression model of age, gender, smoking, drinking, body mass index (BMI), systolic blood pressure (SBP) and diastolic blood pressure (DBP), the relationship between Hcy and other biochemical indicators was evaluated. Results: Among 8063 cases, the age, BMI, SBP and DBP of the high-Hcy group were higher than those of the low-Hcy group, the difference was statistically significant (P<0.05), and the proportion of males, smoking and drinking were higher than the low In the Hcy group, the difference was statistically significant (P<0.05); the ALT, ALP, γ-GT, TBIL, Urea, Cr, UA, and TG in the high Hcy group were higher than those in the low Hcy group, and the difference was statistically significant (P<0.05 ); HDL-c in the high-Hcy group was lower than that in the low-Hcy group, and the difference was statistically significant (P<0.05). There was no statistically significant difference in TC, LDL-c, and GLU between the high- and low-Hcy groups (P>0.05). In multivariate analysis, lnHDL-C was negatively correlated with lnHcy (β=-0.038, SE=0.016, P<0.05), lnCr was positively correlated with lnHcy (β=0.055, SE=0.016, P<0.05), lnUA and lnHcy were positive correlation (β=0.043, SE=0.019, P<0.05). Conclusion: Hcy is closely related to HDL-c, Cr and UA, which indicates that Hcy may affect the metabolism of HDL-c and UA, and can also be used as an auxiliary diagnostic index for kidney injury.

scholarly journals Comparison of Babcock and Ether Extraction Methods for Determination of Fat Content of Cream: Collaborative Study

1996 ◽  
Vol 79 (4) ◽  
pp. 907-916 ◽  
Author(s):  
Joanna M Lynch ◽  
David M Barbano ◽  
J Richard Fleming
Keyword(s):  
Extraction Method ◽  
Collaborative Study ◽  
Extraction Methods ◽  
Fat Content ◽  
Official Method ◽  
Ether Extraction ◽  
Aoac Official ◽  
The Difference ◽  
Aoac Official Method

Abstract A modified Mojonnier ether extraction method for determination of the fat content of cream was developed based on the method for milk (AOAC Official Method 989.05). The cream Babcock method (AOAC Official Method 920.111 B-C) was modified to harmonize with the milk Babcock method (AOAC Official Method 989.04) and to clarify procedural details. Using the AOAC collaborative study format, 10 laboratories tested 9 pairs of blind duplicate heat-treated cream samples with a fat range of 30-45% using both methods. The statistical performance (invalid and outlier data removed) was as follows: mean % fat = 37.932, sr = 0.125, sR = 0.151, RSDr = 0.330, RSDR = 0.398, r = 0.354, and R = 0.427 for the ether extraction method. For the Babcock method, mean % fat = 38.209, sr = 0.209, SR = 0.272, RSDr = 0.548, RSDR = 0.712, r = 0.592, and R = 0.769. Average test results for fat from the Babcock method were 0.277% (absolute fat) greater than for the Mojonnier ether extraction method. The difference between methods, as a percentage of the average fat content of the samples, was 0.73%. This agrees with differences observed between the 2 methods for milk when 10 to 17 laboratories tested 7 milk samples in blind duplicate at bimonthly intervals over a 4-year period (average difference 0.029% fat, 0.78% as a percentage of average fat content). The Mojonnier ether extraction and Babcock methods for fat in cream have been adopted by AOAC INTERNATIONAL. The new Babcock method replaced the AOAC Official Method 920.111 B-C.

Determination of /V-Nitrosodipropylamine in Trifluralin Emulsifiable Concentrates Using Minicolumn Cleanup and Gas Chromatography with Thermal Energy Analyzer

1988 ◽  
Vol 71 (2) ◽  
pp. 333-336
Author(s):  
Dave Wotherspoon ◽  
Ralph Hindle
Keyword(s):  
Gas Chromatography ◽  
Thermal Energy ◽  
Internal Standard ◽  
Energy Analyzer ◽  
Quick Method ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
Artifact Formation ◽  
And Control

Abstract A quick method for determining /V-nitrosodipropylamine (NDPA) levels in trifluralin emulsifiable concentrate formulations is described. At least 18 samples can be analyzed at one time in a minimum of fumehood space, with up to 90% savings on solvents and materials. A sample aliquot is mixed with a solution containing nitrosamine recovery standards, and nitrosamines are separated by minicolumn cleanup. Internal standard is added directly to the eluate containing the nitrosamines, and levels are determined by gas chromatography with thermal energy analyzer. Recoveries of spiked nitrosamines ranged from 98 to 102%. Coefficients of variation for samples containing 0.5 ppm NDPA are 13%. Minimum detectable limit, calculated as 3 times the noise, is 0.06 ppm. Comparison with the method formerly used by this laboratory shows no significant difference in the analytical results at 95% confidence limits, and control experiments were performed to ensure that there was no artifact formation of NDPA.

Methodology for Measurement of Density of Liquid Oxides

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Jan Hrbek ◽  
Bence Mészáros ◽  
Mykhaylo Paukov ◽  
Martin Kudláč
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Extreme Conditions ◽  
Nuclear Accidents ◽  
System A ◽  
Different Temperatures ◽  
Density Values ◽  
Properties Of Materials ◽  
The Difference

Abstract Measurement of physical properties of materials in extreme conditions, such as high temperature, is limited by technological challenges. Nevertheless, modeling of several phenomena relies on the existence of experimental data for their validation. In this study, a method suitable for determination of density in a liquid phase at high temperature is proposed and tested on Al2O3–ZrO2 system. A methodology for acquiring the temperature dependence of density for radioactive materials is proposed and is aimed to refine severe nuclear accidents modeling. The oxide was melted in an induction furnace with a cold crucible. The measurement was based on evaluation of the volume of the melt at different temperatures, in a range from 2100 to 2400 °C. The densities of the oxide in the solid-state and the skull-layer were measured using a pycnometer. A temperature dependence of the density was established and the results were compared with literature. The difference between existing data and the measured values in this work was less than 5%. Thus, the proposed methodology provides reliable density values in extreme conditions.

scholarly journals Liquid Chromatographic Determination of Ivermectin in Feed

1998 ◽  
Vol 81 (4) ◽  
pp. 869-872 ◽  
Author(s):  
Stephen J Doherty ◽  
Allen Fox ◽  
David W Fink
Keyword(s):  
Solid Phase ◽  
Chromatographic Determination ◽  
Phase Extraction ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
Liquid Chromatographic Determination ◽  
Chromatographic Measurement ◽  
Liquid Chromatographic ◽  
Medicated Feeds

Abstract An analytical method for determining ivermectin in feed at 0.50- 3 ppm is presented. The method is based on liquid chromatographic measurement after sample preparation by adsorption chromatography on alumina and solid-phase extraction. Two complete, final, finished medicated feeds and the corresponding control feeds used in their preparation were analyzed. Recoveries from feeds fortified at 50-150% of the 2 ppm ivermectin use concentration also were determined. Mean recoveries from replicate analyses ranged from 90 to 100%, and coefficients of variation (CVs) were less than 4.5%. No significant interferences were found in control feeds. The pooled distribution of individual analytical results (n = 100) gave a mean recovery of 100%, a recovery range of 90-111%, and an overall CV of 5.5%. Resolution of the total variance into its 2 components gave a withinlaboratory CV of 4.1% and a between-laboratory CV of 3.4%. There was no significant difference in recoveries among laboratories, days, concentrations, and feed base or between fortified and medicated feeds (P &gt; 0.2)

Validation Study of Gas Chromatographic Determination of Pentachlorophenol in Animal Liver

1988 ◽  
Vol 71 (5) ◽  
pp. 926-929
Author(s):  
Douglas Gillard ◽  
Robert L Epstein ◽  
Raymond B Ashworth ◽  
Kevin Curry ◽  
Quincy Nathan
Keyword(s):  
Validation Study ◽  
Chromatographic Determination ◽  
Mean Value ◽  
Beef Liver ◽  
Animal Liver ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
Chromatographic Procedure ◽  
Significant Figures

Abstract A validation study was conducted of a gas chromatographic procedure for the determination of pentachlorophenol (PCP) in chicken, pork, and beef liver. Five analysts representing 5 laboratories analyzed randomly numbered blind duplicates at 3 fortified tissue concentrations and one incurred tissue on 2 consecutive days. The PCP concentrations ranged from approximately 40 to 400 parts per billion (ppb). All data were reported to 3 significant figures in ppb. The coefficients of variation for repeatability were between 2.8 and 8.5%, except for the beef liver, at a mean value of 80 ppb PCP, where the CV was 11.3%. The CVs for reproducibility were in the range of 9.7- 16.5% with little significant difference by species. The CV asymptotically approached 10% as the PCP level increased.

Liquid Chromatographic Determination of Salinomycin Sodium in Feed Premix and Biomass Samples

1987 ◽  
Vol 70 (3) ◽  
pp. 504-506 ◽  
Author(s):  
Gary P Dimenna ◽  
James A Creegan ◽  
Lennox B Turnbull ◽  
George J Wright
Keyword(s):  
Extraction Method ◽  
Chromatographic Determination ◽  
Turbidimetric Method ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
The Mean ◽  
Feed Premix ◽  
Liquid Chromatographic ◽  
Refractive Index Detection

Abstract A liquid chromatographic (LC) method has been developed for determination of sodium salinomycin (SS) in feed premix and biomass samples. SS is extracted from samples with acetonitrile, and the extract is diluted to volume. An aliquot is then injected directly into the chromatographic column, and refractive index detection is used to determine the presence of SS. The LC method proved to be both fast and specific; SS was quickly separated from lasalocid, monensin, and narasin. To test the efficiency of this extraction method, premix and biomass samples were spiked with SS. The mean recovery of SS from the spiked premix samples was 101.6%, and from the spiked biomass samples, 99.4%. Six premix samples were then assayed for SS in triplicate on 5 successive days, and 10 biomass samples were assayed for SS in triplicate on 3 different days. The coefficients of variation for the premix assay values ranged from 2.50 to 7.87%. For the biomass assay, CVs ranged from 0.9 to 3.5%. Premix and biomass samples were assayed for SS by this LC method in 2 laboratories and by a turbidimetric method using Bacillus subtilis in a third laboratory. The assay values obtained for SS were equivalent.

Differential assay of zidovudine and its glucuronide metabolite in serum and urine with a radioimmunoassay kit

1990 ◽  
Vol 36 (6) ◽  
pp. 897-900 ◽  
Author(s):  
S M Tadepalli ◽  
L Puckett ◽  
S Jeal ◽  
L Kanics ◽  
R P Quinn
Keyword(s):  
Inhibitory Concentration ◽  
Serum Samples ◽  
Lower Detection Limit ◽  
Coefficients Of Variation ◽  
Lower Detection ◽  
Before And After ◽  
The Difference ◽  
Glucuronide Metabolite ◽  
Serum And Urine

Abstract We developed an ancillary procedure for the ZDV-Trac RIA (Incstar) to allow simultaneous determination of both zidovudine (3'-azido-3'-deoxythymidine, ZDV, AZT, Retrovir) and its metabolite, the glucuronide of ZDV (3'-azido-3'-deoxy-5'-O-beta-D-glucopyranuronosylthymidine, ZDVG, GAZT), in human serum and urine. Using the ZDV-Trac RIA, we measured ZDV concentrations before and after ZDVG in samples was hydrolyzed to ZDV by beta-glucuronidase (EC 3.2.1.31); ZDVG concentration was calculated as the difference between the two results. This method enables rapid evaluation of a large number of samples with a total turn-around time of 6 h. The lower detection limit of the RIA was 0.27 micrograms/L; the measurements varied linearly with ZDV concentrations from 0.27 to 217 micrograms/L, with the 50% inhibitory concentration being approximately 10 micrograms/L. Analytical recoveries of inhouse serum and urine controls for both ZDV and ZDVG exceeded 90%. Coefficients of variation (CVs) of serum controls were less than 6% for ZDV and less than 11% for ZDVG; for urine controls, CVs for both ZDV and ZDVG were less than 6%. Results for ZDVG concentrations obtained by HPLC and by the ZDV-Trac RIA system compared well: r = 0.978, slope 1.0, for serum samples, and r = 0.993, slope 1.09, for urine samples.

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