Liquid-chromatographic determination of progesterone in serum, with spectrophotometric detection.

1986 ◽  
Vol 32 (3) ◽  
pp. 508-510 ◽  
Author(s):  
A Laganà ◽  
G D'Ascenzo ◽  
A Marino ◽  
A M Tarola
Keyword(s):  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Graphitized Carbon Black ◽  
Spectrophotometric Detection ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Chloroform Methanol

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.

scholarly journals Micellar Liquid Chromatographic Determination of Carbaryl and 1-Naphthol in Water, Soil, and Vegetables

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mei-Liang Chin-Chen ◽  
Maria Rambla-Alegre ◽  
Abhilasha Durgbanshi ◽  
Devasish Bose ◽  
Sandeep K. Mourya ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Limit Of Detection ◽  
Cetylpyridinium Chloride ◽  
Sodium Dodecyl ◽  
Chromatographic Determination ◽  
Limit Of Quantification ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

A liquid chromatographic procedure has been developed for the determination of carbaryl, a phenyl-N-methylcarbamate, and its main metabolite 1-naphthol, using a C18 column (250’mm’ × ’4.6’mm) with a micellar mobile phase and fluorescence detection at maximum excitation/emission wavelengths of 225/333’nm, respectively. In the optimization step, surfactants sodium dodecyl sulphate (SDS), Brij-35 andN-cetylpyridinium chloride monohydrate, and organic solvents propanol, butanol, and pentanol were considered. The selected mobile phase was 0.15’M SDS-6% (v/v)-pentanol-0.01’M NaH2PO4buffered at pH 3. Validation studies, according to the ICH Tripartite Guideline, included linearity (r>0.999), limit of detection (5 and 18’ng mL-1, for carbaryl and 1-naphthol, resp.), and limit of quantification (15 and 50’ng mL-1, for carbaryl and 1-naphthol, resp.), with intra- and interday precisions below 1%, and robustness parameters below 3%. The results show that the procedure was adequate for the routine analysis of these two compounds in water, soil, and vegetables samples.

Liquid Chromatographic Determination of Aflatoxin M1 in Milk

1984 ◽  
Vol 67 (4) ◽  
pp. 739-741
Author(s):  
Krystyna Tyczkowska ◽  
James E Hutchins ◽  
Winston M Hagler
Keyword(s):  
Limit Of Detection ◽  
Bovine Milk ◽  
Chromatographic Determination ◽  
Aflatoxin M1 ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Chloroform Methanol ◽  
Porcine Milk

Abstract The official AOAC method for aflatoxin M, in milk was modified by replacing cellulose column chromatography with cartridge chromatographic cleanup and replacing thin layer chromatographic (TLC) determination with liquid chromatographic (LC) quantitation to yield a new method for bovine and porcine milk. An acetone extract of milk is treated with lead acetate and defatted with hexane, and M1 is partitioned into chloroform as in the AOAC method. Chloroform is removed by evaporation under a stream of nitrogen at 50°C. The residue is dissolved in chloroform, the vessel is rinsed with hexane, and the 2 solutions are applied in sequence to a hexane-activated silica Sep-Pak cartridge. Less polar impurities are removed with hexane-ethyl ether, and M1 is eluted with chloroform-methanol, and determined by C18 reverse phase LC using fluorescence detection. Recoveries of M, added to bovine milk at 0.25, 0.50, and 1.0 ng/mL were 90.8, 93.4, and 94.1%, respectively. The limit of detection was less than 0.1 ng M,/mL for both bovine and porcine milk.

Liquid-chromatographic determination of amoxapine and 8-hydroxyamoxapine in human serum.

1982 ◽  
Vol 28 (10) ◽  
pp. 2154-2157 ◽  
Author(s):  
J J Tasset ◽  
F M Hassan
Keyword(s):  
Internal Standard ◽  
Parent Drug ◽  
Chromatographic Determination ◽  
Solvent Mixture ◽  
Reversed Phase ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Toxic Concentrations ◽  
Liquid Chromatographic

Abstract We describe a liquid-chromatographic procedure for amoxapine and 8-hydroxyamoxapine, its active metabolite, in serum. We used a mu-Bondapak C18 reversed-phase column and a mobile phase of acetonitrile/water (74/26 by vol) plus 26 microL of n-butylamine per liter. The compounds were measured at 254 nm, with 8-methoxyloxapine as internal standard. Necessary pre-analysis purification consisted of adsorbing the drug from serum onto extraction columns, eluting with 1-butanol/hexane (1/5 by vol), re-extracting into aqueous acid, and from that re-extracting again into the elution-solvent mixture. We prefer this procedure for monitoring both therapeutic and toxic concentrations of amoxapine, because parent drug and metabolite are measured separately.

Simultaneous liquid-chromatographic determination of 12 common sedatives and hypnotics in serum.

1978 ◽  
Vol 24 (4) ◽  
pp. 657-662 ◽  
Author(s):  
P M Kabra ◽  
H Y Koo ◽  
L J Marton
Keyword(s):  
Serum Proteins ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Acetonitrile Solution ◽  
Column Temperature ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

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.

Liquid Chromatographic Determination of Cyclopiazonic Acid in Corn and Peanuts

1992 ◽  
Vol 75 (2) ◽  
pp. 319-322 ◽  
Author(s):  
Takashi Urano, ◽  
Mary W Trucksess, ◽  
Jean Matusik ◽  
Joe W Dorner
Keyword(s):  
Cyclopiazonic Acid ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Test Portion ◽  
Linear Gradient ◽  
Silica Cartridge ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Chloroform Methanol

Abstract A liquid chromatographic (LC) method Is described for the determination of cyclopiazonic acid (CPA) in corn and peanuts. CPA was extracted from the test portion with methanol-2% NaHC03 solution (7 + 3); the extract was defatted with hexane and then acidified. CPA was partitioned into chloroform and applied to a Sep-Pak silica cartridge. CPA was eluted with chloroform-methanol (3 + 1), the solvent was evaporated, and the residue was dissolved In methanol- water (60 + 40). CPA was quantitated by reversed- phase LC with a linear gradient of 0-4mM ZnS04 In methanol-water (85 + 15) and UV measurement at 279 nm. Recoveries of CPA from corn spiked over the range of 50-500 ng/g and peanuts spiked over the range of 100-500 ng/g were 72-84% and 74-80%, respectively. The limits of quantitation for CPA in corn and peanuts were about 50 and 100 ng/g, respectively. CPA (820 ng/g) was found In corn naturally contaminated with anatoxin Bi, and CPA Identity was confirmed by tandem mass spectrometry.

Liquid-chromatographic determination of nadolol in plasma.

1983 ◽  
Vol 29 (6) ◽  
pp. 1085-1087 ◽  
Author(s):  
R N Gupta ◽  
R B Haynes ◽  
A G Logan ◽  
L A Macdonald ◽  
R Pickersgill ◽  
...  
Keyword(s):  
Plasma Sample ◽  
Antihypertensive Drugs ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Standard Curve ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe a liquid-chromatographic procedure for determining nadolol in plasma. After an analog of nadolol is added as internal standard, the plasma sample is passed through a disposable BondElut C18 column. After several column washes, nadolol and the internal standard are eluted with methanol, and the eluate is evaporated and reconstituted with the mobile phase (acetonitrile/water, perchloric acid, and tetramethylammonium hydroxide). An aliquot of the extract is chromatographed on a non-silica resin-base reversed-phase column. The peaks are detected by fluorescence (lambda ex = 265 nm and lambda em = 305). Drug and internal standard are well resolved, and only a few extraneous peaks appear. The standard curve ranges from 10 to 400 micrograms/L. We are using this procedure to determine steady-state concentrations of nadolol in patients receiving various dosages of nadolol along with other types of antihypertensive drugs.

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
Keyword(s):  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Linear Range ◽  
Limit Of Quantitation ◽  
Standard Linear ◽  
Sample Recovery ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

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).

Liquid-chromatographic determination of alpha- and gamma-tocopherols in erythrocytes, with fluorescence detection.

1983 ◽  
Vol 29 (10) ◽  
pp. 1840-1842 ◽  
Author(s):  
J Lehmann ◽  
H L Martin
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

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.

Liquid Chromatographic Determination of Cyclopiazonic Acid in Poultry Meat

1987 ◽  
Vol 70 (1) ◽  
pp. 121-123 ◽  
Author(s):  
William P Norred ◽  
Richard J Cole ◽  
Joe W Dorner ◽  
John A Lansden
Keyword(s):  
Ligand Exchange ◽  
Cyclopiazonic Acid ◽  
Chromatographic Determination ◽  
Poultry Meat ◽  
Ground Meat ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Chloroform Methanol

Abstract A liquid chromatographic procedure has been developed for the determination of cyclopiazonic acid (CPA) in poultry meat. CPA is extracted from ground meat with chloroform-methanol (80 + 20), partitioned into 0.1 N sodium hydroxide, acidified, and extracted into dichloromethane. An interfering component of meat is removed by transferring the dichloromethane extract to a minicolumn containing silica gel and washing the column with petroleum ether and chloroform. CPA is eluted with methanol-acetic acid (99 + 1), and subjected to ligand-exchange liquid chromatography. Recovery of CPA from 40 separate samples of meat spiked with CPA at levels from 0.016 to 15.6 ppm was 70.4 + 14.1%. Analysis of meat from a chicken orally dosed with 10 mg CPA/kg body weight revealed that 14.5% of the dose was in muscle 48 h after administration.

Simultaneous Liquid Chromatographic Determination of Fenamiphos and Its Metabolites in Soil

1992 ◽  
Vol 75 (1) ◽  
pp. 62-65 ◽  
Author(s):  
R Khazanchi ◽  
S Walia ◽  
S K Handa
Keyword(s):  
Chromatographic Method ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

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.

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