scholarly journals Liquid Chromatographic Determination of Nicarbazin in Feeds

2000 ◽  
Vol 83 (5) ◽  
pp. 1027-1038 ◽  
Author(s):  
Beverly J Krabel ◽  
David A Dickson ◽  
Alan G Zimmermann ◽  
Mark R Coleman

Abstract A new liquid chromatographic method has been developed for determination of nicarbazin in feeds. Approximately 40 g feed is extracted with 200 mL acetonitrile–water (80 + 20, v/v). An aliquot of the extract is filtered and assayed using a reversed-phase isocratic method that measures the 4,4′–dinitrocarbanilide moiety of nicarbazin at a wavelength of 340 nm. For medicated feeds, the method uses a standard linear range of 5 to 100 μg/mL. For lower levels, a linear range of 50 to 150 ng/mL can be used. The method has a limit of detection of 250 ng/g and a limit of quantitation of 500 ng/g in a 40 g feed sample. Recovery was 99.1%, with a range of 95.2 to 101.8%. In the typical U.S. dosing range of 27 to 113.5 g/ton, the precision of the method based on one analyst, one day, and 2 weighings ranged from 2.8% (113.5 g/ton) to 4.7% (27 g/ton).

2003 ◽  
Vol 86 (4) ◽  
pp. 759-763 ◽  
Author(s):  
Peter Cavlovic ◽  
Mohan Mankotia ◽  
Peter Pantazopoulos ◽  
Peter M Scott

Abstract Nightshade berries containing glycoalkaloids can be a contaminant in green peas. Methodology was developed to detect this contamination. The glycoalkaloid α-solasonine was extracted from frozen green peas with 1% (v/v) acetic acid, cleaned up on a C18 cartridge, and determined by liquid chromatography with UV detection at 200 nm. Method performance characteristics for the determination of α-solasonine include linearity from 140 to 1500 ng injected (r = 0.9996–0.9999); recovery ranging from 68 to 79%; limit of quantitation (LOQ) = 4.5 ppm (280 ng standard), and limit of detection = 0.64 ppm (40 ng standard). At the LOQ, the expanded uncertainty at 95% confidence was 0.38 × the reported value. The method was applied to the detection of α-solasonine in frozen green peas in a 2-year study of 60 samples of frozen green peas from Ontario, Canada. None of the samples contained α-solasonine. No unripe berries of Solanum nigrum were detected visually in the samples.


1990 ◽  
Vol 73 (2) ◽  
pp. 298-299
Author(s):  
Thomas C Mueller ◽  
Philip A Banks ◽  
Parshall B Bush ◽  
William C Steen

Abstract A rapid, sensitive method is described for the determination of5-(methylamlno)-2-phenyl-4-[3-(trlfluoromethyl)phenyl]-3- (2M)-furanone (RE-40885) concentrations in 3 soil types. The method consists of extraction of soil samples with methanol, filtration, liquid chromatographic separation of methanolsoluble components using a C18 column, and UV detection at 275 nm. Recoveries were 94, 96, and 94% from the Greenville, Cecil, and Dothan soils, respectively. Average relative standard deviation was 8.0% in the Greenville soil. The qualitative limit of detection was 20 ppb and the limit of quantitation was 40 ppb in 25 g soil samples.


1978 ◽  
Vol 24 (4) ◽  
pp. 657-662 ◽  
Author(s):  
P M Kabra ◽  
H Y Koo ◽  
L J Marton

Abstract We present a method for simultaneously determining 12 hypnotics and sedatives (primidone, methyprylon, phenobarbital, butabarbital, butalbital, ethchlorvynol, pentobarbital, amobarbital, phenytoin, glutethimide, secobarbital and methaqualone) in 200 microliter of serum. Serum proteins are precipitated with an acetonitrile solution containing 5-(4-methylphenyl)-5-phenylhydantoin, the internal standard. The drugs are eluted from a reversed-phase column with a mobile phase consisting of an acetonitrile/phosphate buffer, at a flow rate of 3.0 ml/min. The eluted drugs are detected by their absorption at 195 nm; their quantities are estimated from their peak heights. Each analysis requires no longer than 30 min at the optimum column temperature of 50 degrees C. The lower limit of detection for all of these drugs is less than 10 ng/sample for drug standard. A sensitivity of 1.0 mg/liter of serum is attained routinely for each of the drugs. Analytical recoveries for the 12 drugs varied from 94 to 112%, with good day-to-day precision (CV between 3.8 and 10.4%). Of more than 35 drugs tested for possible interference, only ethotoin interferes with the analysis of phenobarbital.


1983 ◽  
Vol 29 (10) ◽  
pp. 1840-1842 ◽  
Author(s):  
J Lehmann ◽  
H L Martin

Abstract We have adapted to erythrocytes a method for the determination of alpha- and gamma-tocopherols in plasma and platelets. Erythrocytes (50 microL) were extracted with methanol containing tocol (internal standard) and pyrogallol. Tocopherols were partitioned into chloroform, washed, and injected in methanol onto a reversed-phase (C18) "high-performance" liquid-chromatographic column. The mobile phase was methanol/water (99/1 by vol) at a flow rate of 2 mL/min and detection was with a "high-performance" spectrophotofluorometer. The limit of detection for either tocopherol is 0.10 microgram/mL of packed cells. Analytical recoveries ranged from 93 to 104%. Some values for tocopherols in human erythrocytes are presented.


1992 ◽  
Vol 75 (1) ◽  
pp. 62-65 ◽  
Author(s):  
R Khazanchi ◽  
S Walia ◽  
S K Handa

Abstract A reversed-phase liquid chromatographic method has been developed for the determination of fenamiphos and the metabolites fenamiphos sulfoxide, fenamiphos sulfone, 3-methyl-4-(methylthlo)- phenol, and 3-methyl-4-(methylsulflnyl)phenol. Trace quantities of the nematlclde and Its metabolites In soil can be determined simultaneously. The limit of detection of the method was 5 ppm. Recoveries of fenamiphos and Its degradation products at fortification levels of 25,50, and 100 ppm ranged from 99.2 to 100.8%. Standard deviations ranged from 0.29 to 0.70 ppm.


1986 ◽  
Vol 32 (3) ◽  
pp. 508-510 ◽  
Author(s):  
A Laganà ◽  
G D'Ascenzo ◽  
A Marino ◽  
A M Tarola

Abstract In this precise, accurate, and specific liquid-chromatographic procedure for determining progesterone in serum, the serum is diluted 10-fold with water/methanol (65/35 by vol), and the progesterone is extracted from the sample by passage through a column of graphitized carbon black (Carbopack B, Supelco). After washing the column, we elute the progesterone with chloroform/methanol (90/10 by vol), which is then evaporated. The progesterone is separated on a reversed-phase C18 column with a mobile phase of acetonitrile/water, (46/54 by vol) at a flow rate of 1.6 mL/min. The eluted compound is detected by absorbance at 242 nm. Analytical recoveries for progesterone varied from 96.0 to 97.8%. Within-day and day-to-day precision, determined by analyzing pooled serum, ranged from 3.4 to 6.4%, and 4.1 to 7.9%, respectively. The limit of detection was about 0.2 micrograms/L. Numerous drugs and steroids tested did not interfere. Results correlated (r = 0.997) well with those by radioimmunoassay.


1994 ◽  
Vol 77 (6) ◽  
pp. 1447-1453 ◽  
Author(s):  
Pauline M Lacrok ◽  
Norman M Curran ◽  
Wing-Wah Sy ◽  
Dennis K J Goreck ◽  
Pierre Thibault ◽  
...  

Abstract A liquid chromatographic method for the determination of amiodarone hydrochloride and 10 related compounds in drug raw material and for assay of drug in tablets was developed. The method specifies a 3 jxm Hypersil nitrile column (150 × 4.6 mm), a mobile phase of 1 + 1 acetonitrile–ammonium acetate buffer (0.1 M adjusted to pH 6.0 with 0.1 M acetic acid), a flow rate of 1 mL/min, and detection at 240 nm. The lower limit of quantitation of the related compounds is 0.02% or less. Drug contents in 2 raw material samples were 100.1 and 99.9% and ranged from 98.2 to 99.4% in 3 tablet formulations. Impurity levels in 2 samples of raw material from different manufacturers were ca 0.4%. The presence of 3 of the known related compounds in these samples was confirmed by liquid chromatographymass spectrometry. The method applied to raw materials was evaluated by a second laboratory and found to be satisfactory.


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