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At least 307 records · Page 17Linked to original sources
PubMed1987

Fluorometry of poultry semen: influence of dilution and storage on chicken spermatozoal viability and fertility.

Two experiments were conducted to measure the effects of semen dilution and storage time (0, 1, 2, 3, 4, 24, and 48 h) at 22 C on spermatozoal viability (i.e., membrane permeability to ethidium bromide) and to determine the relationship between concentration of viable spermatozoa inseminated (25, 50, 100, and 200 x 10(6] and fertility. In Experiment 1, percentages of dead spermatozoa remained relatively constant during the 4-h postcollection period but increased significantly (P less than .05) at 24 and 48 h. Sperm viability after 48 h was significantly higher in diluted semen than in undiluted semen. Percent (PF) and duration of fertility (DF) from undiluted semen significantly declined during the 4-h postcollection period compared with fertility of diluted semen. In Experiment 2, both PF and DF improved as the concentration of viable spermatozoa increased. Fertility was not significantly improved by inseminating more than 100 X 10(6) viable spermatozoa. The fertilizing capacity of chicken spermatozoa from undilated semen was affected during storage before membrane permeability to ethidium bromide was altered.

Animals↗
PubMedDate not supplied

Rapid immunoaffinity-based method for determination of zearalenone in corn by fluorometry and liquid chromatography.

An immunoaffinity-based method was developed to determine zearalenone in corn. Corn samples were extracted in acetonitrile-water (90 + 10, v/v), applied to an immunoaffinity column, and eluted with methanol. The isolated toxin was quantitated either by reaction with aluminum chloride hexahydrate (AlCl3.6H2O) prior to measurement with a fluorometer or injection into a liquid chromatographic (LC) system with a fluorescence detector. Performance was evaluated in terms of antibody specificity, limit of detection, percentage recovery, precision, column capacity, assay linearity, and comparison with AOAC Official Method 985.18. With the immunoaffinity column cleanup procedure, only zearalenone and its metabolites were recognized by the antibody (> or = 75% recovery). Limits of detection were 0.10 microgram/g for the fluorometer and 0.10 or 0.0025 microgram/g (sensitive method) for the LC method. Percentage recovery averaged 105% (fluorometer) and 93% (LC method), with average relative standard deviations (RSDs) of 15.7 and 9.3%. Naturally contaminated samples gave comparable RSDs of 8.3 and 9.9% for the fluorometer and LC methods, respectively. Column capacity was 4.0 micrograms with 89% recovery. Assay linearity was comparable for both methods (r2 = 0.998). Optimum assay ranges were 0.10-5.0 micrograms/g for the fluorometer and 0.10-50 or 0.0025-5.0 micrograms/g (sensitive method) for the LC method. Comparative analysis of 17 naturally contaminated corn samples using Zearala Test LC and the official AOAC LC method for detection of zearalenone showed that Zearala Test is statistically comparable to the AOAC Official Method 985.18 (r2 = 0.747).

Antibody Specificity↗
PubMed1975

Determination of coumaphos and its oxygen analog in eggs by in situ fluorometry.

A method is reported for the simultaneous determination of coumaphos (o,o-diethyl o(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl)phosphorothioate) and its oxygen analog, Coroxon, in eggs in the ppb range. The residues are extracted with acetone and chloroform. The extract is purified by liquid-liquid partition followed by column chromatography and then by 2-dimensional thin layer chromatography. The fluorescence is measured directly on the chromatogram.

Animals↗
PubMedDate not supplied

Determination of nalidixic acid by fluorometry with sodium borohydride and hydrogen peroxide.

A simple and sensitive fluorometric method for the determination of nalidixic acid was established by using 0.75M sodium borohydride and 7.5% hydrogen peroxide solution as fluorogenic reagents. Analyte concentrations of 0.0232-11.6 pg/mL could be determined with high precision and accuracy by the method. A relative standard deviation of 1.75% was obtained for a nalidixic acid concentration of 0.232 pg/mL. The method was satisfactorily applied to the determination of nalidixic acid in human serum, fish muscle, and chicken muscle, and the calibration curves were linear from 0.23 to 58.00 pg/mL, from 9.28 to 32.48 mg/kg, and from 4.64 to 23.20 mg/kg, respectively. The specificity of the reaction is also discussed.

Animals↗
PubMed1976

Determination of quinomethionate (6-methylquinoline-2,3-diyldithiocarbonate) residues in crops by in situ fluorometry.

A simple method is described for the quantitative determination of quinomethionate (6-methylquinoline- 2,3 - diyldithiocarbonate) in crops. The pesticide residue is extracted with acetonitrile and partitioned in petroleum ether. After separation from the co-extractives by thin layer chromatography (TLC), the fluorescence is measured directly on a silica gel TLC plate. An average of 89% recovery is obtained at the 0.05 ppm level in apples, peaches, pears, and tomatoes.

Chromatography, Thin Layer↗
PubMed1976

Fluorometry of plasma amino nitrogen, with use of fluorescamine.

We describe a fluorometric procedure, with use of fluorescamine, for determining plasma amino nitrogen in a 10-mul sample of deproteinized plasma. Values for apparently healthy human subjects agree well with those obtained by spectrophotometry. The simplicity and speed of the assay recommends it as a screening procedure for detecting aminoacidopathies.

Adult↗