Calibration and validation of a carbon oxidation system and determination of the bicarbonate retention factor and the dietary phenylalanine requirement, in the presence of excess tyrosine, of adult, female, mixed-breed dogs

2017 ◽  
Vol 95 (7) ◽  
pp. 2917
Author(s):  
A. K. Shoveller ◽  
J. J. Danelon ◽  
J. L. Atkinson ◽  
G. M. Davenport ◽  
R. O. Ball ◽  
...  
Keyword(s):  
Adult Female ◽  
Retention Factor ◽  
Carbon Oxidation ◽  
Calibration And Validation ◽  
Mixed Breed ◽  
Oxidation System

scholarly journals Nitrogen balance in adult female mink (Mustela vison) in response to normal feeding andshort-term fasting

1997 ◽  
Vol 78 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Anne-Helene Tauson ◽  
Jan Elnif ◽  
Søren Wamberg
Keyword(s):  
Urinary Excretion ◽  
Renal Clearance ◽  
Adult Female ◽  
Accurate Determination ◽  
Mustela Vison ◽  
Published Data ◽  
Purine Derivatives ◽  
Total N ◽  
Creatinine Excretion

Ten adult female mink (Mustela vison) were studied in a 7 d balance experiment consisting of a 2 d pre-surgery feeding period, followed by surgery, 1 d of recovery, 4 d of ad libitum feeding, and a 2d fasting period. In this experiment (Expt A) the animals had osmoticpumps implanted for continuous release of radioactively-labelled p–aminohippuric acid (p–aminobenzoyl-2-[3H]glycine; [3H]PAH;n10) and 14C-labelled inulin ([14C]IN; n 5). Repeated 24 h collections of urine, corrected to 100%[3H]PAH or [14C]IN recovery, were used for accurate determination of N balances, 24 h urinary excretion of urea, creatinine, and total N, and calculation of mean 24 h renal clearance rates for endogenous creatinine and inulin. N balances were slightly below zero, but not significantly different between feeding and fasting periods, indicating that correction to 100% [3H]PAH recovery resulted in slight overestimation of thefinal balances. During fasting, withdrawal of the dietary water and protein loads resulted in a dramatic decline in 24 h urinary volume, and urea and creatinine excretion. Large individualvariations in 24h urinary creatinine excretion (with relative variation coefficients up to 30%) confirmed that this is an unreliable index of the completeness of urine collection. In this respect, recovery rates of [3H]PAH proved far more consistent. Renal clearance values obtained in fed mink were in fair agreement with published data from cats, dogs and ferrets (Mustela putorius furo). Inulin clearance was about 30% higher than endogenous creatinine clearance, although its decline in response to fasting was not significant. In a separate study (Expt B)another ten female mink were equipped with osmotic pumps containing [3H]PAH for determination of 24 h excretion rates of purine derivatives. During feeding, allantoin accounted for more than 97 % of the excretion of purine derivatives in urine, uric acid making up less than 2·5%, xanthine and hypoxanthine less than 1 %. In fasted animals, urinary excretion of each of these purine derivatives declined to less than 50% of the feeding value. In conclusion, an experimental technique is presented for efficient and accurate measurements of daily urinary excretion of nitrogenous constituents, which allows for correct determination of N balances in adult mink and, presumably, in other mammalian species.

scholarly journals Determination of the retention factor of ionizable compounds in microemulsion electrokinetic chromatography

2019 ◽  
Vol 1078 ◽  
pp. 221-230 ◽  
Author(s):  
Alejandro Fernández-Pumarega ◽  
Susana Amézqueta ◽  
Elisabet Fuguet ◽  
Martí Rosés
Keyword(s):  
Retention Factor ◽  
Electrokinetic Chromatography ◽  
Microemulsion Electrokinetic Chromatography ◽  
Ionizable Compounds

scholarly journals IDENTIFICATION, QUANTIFICATION AND VALIDATION OF STIGMASTEROL FROM ALPINIA CALCARATA USING HIGH-PERFORMANCE THIN LAYER CHROMATOGRAPHY METHOD

2017 ◽  
Vol 9 (9) ◽  
pp. 126
Author(s):  
Pratheema Philomindoss
Keyword(s):  
Linear Regression ◽  
Thin Layer ◽  
Linear Relationship ◽  
High Performance ◽  
Retention Factor ◽  
Chromatography Method ◽  
Ich Guidelines ◽  
Layer Chromatography ◽  
Hptlc Method

Objective: The present study is designed to develop a new simple, precise, rapid and selective high‐performance thin‐layer chromatographic (HPTLC) method for the determination of stigmasterol in methanolic rhizomes extract of Alpinia calcarata.Methods: As per International Conference on Harmonization (ICH) guidelines we have applied different concentrations of stigmasterol as standard on HPTLC plates for the quantification of stigmasterol from the Alpinia calcarata rhizomes. The concentration of standard stigmasterol is 1 mg/ml.Results: The retention factor of stigmasterol was 0.58. Linearity was obtained in the range of 50 ng‐250 ng for stigmasterol. The developed and validated HPTLC method was employed for stigmasterol in methanolic rhizomes extract of Alpinia calcarata for standardization of the content of the marker. The linear regression data for the calibration plots showed a good linear relationship with r=0.99977 for stigmasterol, respectively Satisfactory recoveries of 99.77 % were obtained for stigmasterol.Conclusion: The results obtained in validation assays indicate the accuracy and reliability of the developed HPTLC method for the quantification of stigmasterol in methanolic rhizomes extract of Alpinia calcarata

scholarly journals Determination of lipophilicity for antitumor acridinone derivatives supported by gradient high-performance liquid chromatography method

2012 ◽  
Vol 10 (1) ◽  
pp. 216-223 ◽  
Author(s):  
Marcin Koba ◽  
Mariusz Belka ◽  
Tomasz Ciesielski ◽  
Tomasz Bączek
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Retention Factor ◽  
Reversed Phase ◽  
Log P ◽  
Chromatography Method ◽  
Factor Log ◽  
Liquid Chromatography Method

AbstractThe lipophilicity values of selected acridinone (imidazoacridinone and triazoloacridinone) derivatives were measured by gradient reversed-phase high-performance liquid chromatography (RP-HPLC) using a C18 stationary phase with a water/acetonitrile mixture as a mobile phase. The retention times obtained served as input data and appropriate log kw values (i.e., the retention factor log kw extrapolated to 0% organic modifier) as an alternative to log P were calculated using the DryLab program. The relationships between the lipophilicity (log kw) and the chemical structure of the studied compounds, as well as correlation between experimentally determined lipophilicities (log kw) and log P data calculated using some commonly available software, are discussed.

RP-HPLC-DAD method for simultaneous determination of desmedipham, phenmedipham and ethofumesate in a pesticide formulation

2012 ◽  
Vol 31 (1) ◽  
pp. 39 ◽  
Author(s):  
Lenče Velkoska-Markovska ◽  
Biljana Petanovska-Ilievska ◽  
Lila Vodeb
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
Limit Of Detection ◽  
Retention Factor ◽  
Reversed Phase ◽  
Limit Of Quantification ◽  
Column Temperature ◽  
Pesticide Formulation ◽  
Factor Separation

A fast, simple, precise and accurate reversed-phase high-performance liquid chromatography (RPHPLC)method with UV-DAD for simultaneous determination of desmedipham, phenmedipham and ethofumesate in the pesticide formulation “Inter OF” has been developed. The analysis was performed on a LiChrospher 60 RP-select B (25 cm × 0.4 cm, 5 μm, Merck) analytical column, with mobile phase of methanol/water (60/40, V/V), flow rate of 1 ml/min, UV-detection at 230 nm and constant column temperature at 25 ºC. The following parameters were determined for the developed method: retention factor, separation factor, limit of detection (LOD), limit of quantification (LOQ), precision of obtained results for peak area, linearity, recovery of analyte and active ingredients quantity in a pesticide formulation.

Determination Methods of Dialdehyde Celluloses from Bacterial Cellulose

2007 ◽  
Vol 361-363 ◽  
pp. 507-510
Author(s):  
Yu Hong Feng ◽  
Jia Cheng Li ◽  
Qiang Lin ◽  
Su Juan Pang ◽  
Meng Ying Zhang ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
Amino Nitrogen ◽  
Aldehyde Group ◽  
Acid Base ◽  
Titration Method ◽  
Cannizzaro Reaction ◽  
Acid Base Titration ◽  
Determination Methods ◽  
Oxidation System

This paper addresses the determination of aldehyde group (% of dialdehyde units) in dialdehyde cellulose (DACs) oxidized from bacterial cellulose (BC). With 4 determination methods, the oxidation degrees of DACs were studied: Automatic potential titration method through Schiff base reaction, Acid-base titration in Cannizzaro reaction, Metaperiodate consumption determination, and Measurement of amino nitrogen content in DAC derivatives. By comparing determination results of these methods, we found out the proper way suitable for this metaperiodate oxidation system of BC to measure the dialdehyde unit content of the DACs.

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