Microbiological Method for Assaying Nystatin in Animal Feeds

1963 ◽  
Vol 46 (3) ◽  
pp. 438-444
Author(s):  
Joseph F Pagano
Keyword(s):  
Microbiological Assay ◽  
Microbiological Method ◽  
Animal Feeds ◽  
Assay Procedure ◽  
Feed Samples

Abstract A microbiological assay procedure for the determination of nystatin2 in animal feeds at levels as low as 2 5 ppm has been developed. The assay procedure and two feed samples were submitted to five collaborating laboratories for evaluation. The results of the collaborative assay study are presented, and it is recommended that the method be adopted as official, first action.

Comparison of Chemical and Microbiological Methods for the Determination of Procaine Penicillin in Premixes and Mixed Feeds

1963 ◽  
Vol 46 (3) ◽  
pp. 429-433
Author(s):  
Stanley E Katz
Keyword(s):  
Chemical Method ◽  
Microbiological Assay ◽  
Assay Method ◽  
Microbiological Method ◽  
Procaine Penicillin ◽  
Assay Procedure ◽  
Microbiological Methods ◽  
Mixed Feeds

Abstract A chemical and a microbiological method of analysis for procaine penicillin in premixes and mixed feeds have been compared. The microbiological assay method was a typical cylinderplate assay procedure. The chemical method was based upon the conversion by base of penicillins to penicilloic acids. In the eight premixes studied, the chemical-to-microbiological ratio of results varied from 0.92 to 1.17. In four mixed feeds, the ratio varied from 0.97 to 1.09. In general, the chemical method yielded slightly higher results than the microbiological method. There was little difference between methods in regard to reproducibility and accuracy.

scholarly journals Multiresidue method for the simultaneous analysis of antibiotics and mycotoxins in feeds by ultra-high performance liquid chromatography coupled to tandem mass spectrometry

2021 ◽  
Author(s):  
Ü.İ. Konak ◽  
H.A. Yatmaz ◽  
Ş. Nilüfer ◽  
T. Erkaymaz ◽  
M. Certel
Keyword(s):  
High Performance ◽  
Safety Issue ◽  
Animal Health ◽  
Animal Origin ◽  
Limit Of Quantification ◽  
Multiresidue Method ◽  
Animal Feeds ◽  
Relative Standard ◽  
Feed Samples

AbstractResidues in animal feeds and foods of animal origin have been important safety issue concerning both human and animal health. A multiresidue method for determination of eight mycotoxins and ten antibiotics was developed and validated in animal feeds by using QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction followed by UHPLC-MS/MS. Optimisation of UHPLC-MS/MS parameters was performed to achieve good separation and resolution. The method was validated according to the European Commission Decision 2002/657/EC. Matrix matched calibration curves showed good r2 (≥0.995) values, and limit of quantification (LOQ) values varied between 1.2 and 5.2 μg kg−1. Average recoveries ranged from 60 to 102% with relative standard deviations of 2.2 and 15.6% for all type of feed samples except for tetracyclines, lincomycin, tylosin, ochratoxin A, and fumonisin (B1 and B2).

Comparison of Methods for Determination of Lysine in Cereals

1963 ◽  
Vol 46 (3) ◽  
pp. 399-405
Author(s):  
Y Pomeranz ◽  
B S Miller
Keyword(s):  
Ion Exchange ◽  
Paper Chromatography ◽  
Microbiological Assay ◽  
Two Dimensional ◽  
Comparison Of Methods ◽  
Microbiological Method ◽  
Exchange Method ◽  
Wheat Products ◽  
Ion Exchange Method

Abstract The lysine contents of 10 milled wheat products and cereal foods were determined by microbiological, enzymatic, two-dimensional paper chromatographic, and ion exchange chromatographic methods. The assay of lysine by two-dimensional paper chromatography produced very low results. The results from the microbiological method were comparable to those by the ion exchange method. The decarboxylase method consistently gave low results which averaged 82% of those obtained by the microbiological assay. Possible reasons for these low results are presented and discussed.

Determination of Crude Protein in Animal Feeds, Using Block Digestion Followed by Steam Distillation: Collaborative Study

1979 ◽  
Vol 62 (2) ◽  
pp. 290-291
Author(s):  
Rodney J Noel
Keyword(s):  
Statistical Analysis ◽  
Crude Protein ◽  
Steam Distillation ◽  
Collaborative Study ◽  
Alternative Technique ◽  
Animal Feeds ◽  
Ammonia Determination ◽  
Kjeldahl Method ◽  
Feed Samples

Abstract A method consisting of digesting animal feeds in a block digestor and determining ammonia by steam distillation followed by titration has been evaluated and compared with the official final action Kjeldahl method, 7.016. Fifteen laboratories analyzed 5 feed samples and lysine monohydrochloride. Statistical analysis showed that results from the 2 methods were comparable. The distillation technique has been adopted as official first action as an alternative technique for ammonia determination from the digest of the official final action block digestor method, 7.B11.

Collaborative Study of a Semiautomated Method for the Determination of Crude Protein in Animal Feeds

1976 ◽  
Vol 59 (1) ◽  
pp. 134-140 ◽  
Author(s):  
Rodney J Noel ◽  
Larry G Hambleton
Keyword(s):  
Crude Protein ◽  
Primary Standard ◽  
Collaborative Study ◽  
Dihydrogen Phosphate ◽  
Ammonium Dihydrogen Phosphate ◽  
Animal Feeds ◽  
Kjeldahl Method ◽  
Feed Samples ◽  
Semiautomated Method

Abstract A semiautomated method consisting of digestion of animal feeds in a block digestor and determination of ammonia by ammonia-salicylate reaction has been studied collaboratively, along with the official final action Kjeldahl method, sec. 7.016. Each collaborator analyzed 16 feed samples, tryptophan, ammonium dihydrogen phosphate NBS standard, and ammonium sulfate primary standard. Statistical analysis showed that the 2 methods agreed. The semiautomated method has been adopted as official first action.

DETERMINATION OF GLUTAMINE AND GLUTAMIC ACID IN THE BLOOD PLASMA OF CHICKS BY A COMBINED CHROMATOGRAPHIC AND MICROBIOLOGICAL METHOD

1962 ◽  
Vol 40 (1) ◽  
pp. 381-390 ◽  
Author(s):  
Ellen M. Olsen ◽  
D. C. Hill ◽  
H. D. Branion
Keyword(s):  
Glutamic Acid ◽  
Blood Plasma ◽  
Lactobacillus Plantarum ◽  
Test Organism ◽  
Microbiological Assay ◽  
Acetate Buffer ◽  
Microbiological Method ◽  
Chromatographic Procedure

Glutamine was separated from glutamic acid by chromatographing deproteinized plasma on a 10-cm column of Dowex 1X8 and by eluting with acetate buffer, pH 4.2. The first portion of eluate, which contained the glutamine but no glutamic acid, was subjected to microbiological assay using Lactobacillus plantarum as a test organism. Recovery of glutamine added to plasma was satisfactory and the precision of the assays conducted was within 4%. Several substances were found to interfere with the microbiological assay but these were eliminated by the chromatographic procedure. The method was extended to the determination of glutamic acid by continued elution of the column with acetate buffer, pH 4.2, fractionation of the eluate, and determination with ninhydrin. Average glutamine and glutamic acid contents of plasma of normal non-fasting chickens were 12.8 and 3.4 mg per 100 ml respectively.

Semiautomated Method for Simultaneous Determination of Phosphorus, Calcium, and Crude Protein in Animal Feeds

1977 ◽  
Vol 60 (4) ◽  
pp. 845-852 ◽  
Author(s):  
Larry G Hambleton
Keyword(s):  
Simultaneous Determination ◽  
Crude Protein ◽  
Animal Feed ◽  
Mixed Feed ◽  
Animal Feeds ◽  
Aoac Method ◽  
Feed Samples ◽  
Semiautomated Method

Abstract A semiautomated method was developed for the simultaneous determination of phosphorus, calcium, and crude protein in animal feeds. Samples are digested with a block digestor, diluted to volume, and analyzed at the rate of 40 samples/hr. Protein is determined by the official AOAC method, by measuring the absorbance of an ammonia-salicylate complex at 660 nm. Phosphorus and calcium are determined by measuring the absorbances of the molybdovanadophosphate and calcium-cresolphthalein complexes at 420 and 570 nm, respectively. Samples are weighed according to the amount of protein they contain. Over 90% of the mixed animal feed samples analyzed for phosphorus and calcium fall within the range of the instrument; provisions are made for single determinations on those samples that fall outside the specified ranges. Results correlate well for the semiautomated method and official AOAC methods on mixed feed check samples and NBS Standard Reference Orchard Leaves.

DETERMINATION OF GLUTAMINE AND GLUTAMIC ACID IN THE BLOOD PLASMA OF CHICKS BY A COMBINED CHROMATOGRAPHIC AND MICROBIOLOGICAL METHOD

1962 ◽  
Vol 40 (3) ◽  
pp. 381-390 ◽  
Author(s):  
Ellen M. Olsen ◽  
D. C. Hill ◽  
H. D. Branion
Keyword(s):  
Glutamic Acid ◽  
Blood Plasma ◽  
Lactobacillus Plantarum ◽  
Test Organism ◽  
Microbiological Assay ◽  
Acetate Buffer ◽  
Microbiological Method ◽  
Chromatographic Procedure

Glutamine was separated from glutamic acid by chromatographing deproteinized plasma on a 10-cm column of Dowex 1X8 and by eluting with acetate buffer, pH 4.2. The first portion of eluate, which contained the glutamine but no glutamic acid, was subjected to microbiological assay using Lactobacillus plantarum as a test organism. Recovery of glutamine added to plasma was satisfactory and the precision of the assays conducted was within 4%. Several substances were found to interfere with the microbiological assay but these were eliminated by the chromatographic procedure. The method was extended to the determination of glutamic acid by continued elution of the column with acetate buffer, pH 4.2, fractionation of the eluate, and determination with ninhydrin. Average glutamine and glutamic acid contents of plasma of normal non-fasting chickens were 12.8 and 3.4 mg per 100 ml respectively.

Microbiological Assay of Thiopeptin in Broiler Rations

1977 ◽  
Vol 60 (1) ◽  
pp. 206-209
Author(s):  
Norio Takano ◽  
Kimiko Nomura ◽  
Akira Arakawa
Keyword(s):  
Microbiological Assay ◽  
Assay Method ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Acetone Water ◽  
Paper Disk ◽  
Average Recovery Rate ◽  
Low Levels ◽  
Feed Samples

Abstract A microbiological assay method is described for the determination of thiopeptin in poultry feeds. Feed samples are extracted with acetone-water (9+1). Interfering substances are compensated for by extracting standard solutions from antibiotic-free feed. Microbiological activity is measured on monolayer agar plates by the paper disk diffusion method with Acholeplasma laitllaivii A. Concentrations are calculated from the responses to high and low levels of the unknown and the standard. A mean recovery of 96% was obtained from samples prepared by fortifying basal feeds in the laboratory with thiopeptin at concentrations ranging from 0.6 to 2.0 mg/kg shortly before extraction. The average recovery rate was 93% in feed samples prepared by 5 feed manufacturers with thiopeptin concentrations ranging from 0.6 to 2.5 g/ton.

scholarly journals Rapid Forensic Selected Reaction Monitoring Liquid Chromatography/Mass Spectrometry Determination of Ionophore Antibiotics Found at Toxic Levels in Animal Feeds

2004 ◽  
Vol 87 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Joseph G Ebel ◽  
Timothy Wachs ◽  
Jack D Henion
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Extraction Procedure ◽  
Rapid Identification ◽  
Selected Reaction Monitoring ◽  
Reaction Monitoring ◽  
Triple Quadrupole Mass Spectrometer ◽  
Animal Feeds ◽  
Feed Samples

Abstract A rapid, accurate, and selective method was developed for the forensic determination of ionophore antibiotics in animal feeds. A simple extraction procedure and liquid chromatography/tandem mass spectrometry (LC/MS/MS) in the selected reaction monitoring (SRM) mode were used for rapid identification and confirmation of monensin and lasalocid in feed samples and for quantitation of monensin. Extracts from a homogenous portion of ground feeds were prepared using liquid–solid extraction and liquid–liquid extraction techniques. Feed extracts were further purified by a simple defatting and solvent wash step and then concentrated to dryness. Feed extract residues were reconstituted in 1 mL LC mobile phase and a 2 μL aliquot injected into the SRM LC/MS system. The latter system used a C18, 100 × 2.0 mm, LC column coupled to a PE-Sciex API 2000 tandem triple quadrupole mass spectrometer equipped with a TurboIonSpray LC/MS interface. Feed samples were extracted and analyzed for the determination of monensin and lasalocid within a couple of hours. Control feed samples fortified with monensin at concentrations from 50 ppb to 5 ppm provided a linear response and calibration curve across this range with a correlation coefficient of 0.996.

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