Gas-chromatographic determination of amantadine in human urine.

1980 ◽  
Vol 26 (2) ◽  
pp. 295-296 ◽  
Author(s):  
M J Stumph ◽  
M W Noall ◽  
V Knight
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Organic Layer ◽  
Liquid Chromatographic Method ◽  
Analytical Recovery ◽  
Instrument Response ◽  
Aqueous Layer ◽  
Liquid Chromatographic

Abstract We describe a gas--liquid-chromatographic method for determining the concentration of amantadine hydrochloride in urine with beta-phenylethylamine as internal standard. The urine sample is made alkaline and extracted with 0.5 mL of chloroform. After centrifugation the aqueous layer is aspirated, and an aliquot of the organic layer is injected directly into the gas chromatograph. Concentration and instrument response are linearly related between 2 and 125 mg/L. The limit of detection was 0.5 mg/L. Mean analytical recovery was calculated to be 97%.

Gas-chromatographic determination of amantadine in human urine.

1980 ◽  
Vol 26 (2) ◽  
pp. 295-296 ◽  
Author(s):  
M J Stumph ◽  
M W Noall ◽  
V Knight
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Organic Layer ◽  
Liquid Chromatographic Method ◽  
Analytical Recovery ◽  
Instrument Response ◽  
Aqueous Layer ◽  
Liquid Chromatographic

Abstract We describe a gas--liquid-chromatographic method for determining the concentration of amantadine hydrochloride in urine with beta-phenylethylamine as internal standard. The urine sample is made alkaline and extracted with 0.5 mL of chloroform. After centrifugation the aqueous layer is aspirated, and an aliquot of the organic layer is injected directly into the gas chromatograph. Concentration and instrument response are linearly related between 2 and 125 mg/L. The limit of detection was 0.5 mg/L. Mean analytical recovery was calculated to be 97%.

Gas-Liquid Chromatographic Determination of T-2 Toxin in Plasma

1983 ◽  
Vol 66 (4) ◽  
pp. 909-912 ◽  
Author(s):  
Steven P Swanson ◽  
Venkatachalam Ramaswamy ◽  
Val R Beasley ◽  
William B Buck ◽  
Harold H Burmeister
Keyword(s):  
Chromatographic Method ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Aqueous Sodium Hydroxide ◽  
Chromatographic Determination ◽  
Florisil Column ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract The gas-liquid chromatographic method for the determination of T-2 toxin in plasma is described. The toxin is extracted with benzene, washed with aqueous sodium hydroxide, and chromatographed on a small Florisil column; the heptafluorobutyryl derivative is prepared by reaction with heptafluorobutyrylimidazole. The T-2 HFB derivative is chromatographed onOV-1 at 230°C and measured with an electron capture detector. Iso-T-2, an isomer of T-2 toxin, is added to samples as an internal standard before extraction. Recoveries averaged 98.0 ± 5.5% at levels ranging from 50 to 1000 ng/m L. The limit of detection is 25 ng/mL.

Determination of promethazine in serum by liquid chromatography.

1981 ◽  
Vol 27 (2) ◽  
pp. 253-255 ◽  
Author(s):  
J E Wallace ◽  
E L Shimek ◽  
S C Harris ◽  
S Stavchansky
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Rectal Administration ◽  
Single Extraction ◽  
Analytical Recovery ◽  
Promethazine Hydrochloride ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe a procedure for the liquid-chromatographic determination of promethazine in low-nanogram concentrations in serum. Triflupromazine is used as the internal standard. The method is based on a single extraction of promethazine from serum with hexane and subsequent derivatization with trichloroethyl chloroformate. Analytical recovery of promethazine is about 90%. The lower limit of detection is 1 microgram/L when a 2.0-mL aliquot of serum is assayed. Our data illustrate the practicability of the method for bioavailability studies after oral or rectal administration of promethazine hydrochloride.

Liquid-chromatographic determination of amiodarone and N-desethylamiodarone in serum

1990 ◽  
Vol 36 (3) ◽  
pp. 532-534 ◽  
Author(s):  
C N Ou ◽  
C L Rognerud ◽  
L T Duong ◽  
V L Frawley
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Isopropyl Ether ◽  
Organic Layer ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract We have developed a stable and simple normal-phase liquid-chromatographic method for simultaneously measuring amiodarone and its metabolite, N-desethylamiodarone, within 8 min. The chromatographic system consists of a 15 cm x 3.9 mm Waters "Resolve" silica column and a mobile phase of ammonium sulfate (17 mmol/L, pH 6.8) and methanol (8/92 by vol), pumped at 1.8 mL/min and monitored at 254 nm. After 250 microL of serum is mixed with 100 microL of 0.36 mol/L NaH2PO4, 100 microL of the internal standard solution (L8040, 6 mg/L), and 200 microL of isopropyl ether, the mixture is vortex-mixed and centrifuged. Fifty microliters of the organic layer is injected onto the column. Relative recovery was 100% over the assay range of 0.1 to 20.0 mg/L for both compounds. Within-run and total (day-to-day) CVs were 3% and 7% for amiodarone and 5% and 8% for N-desethylamiodarone, respectively.

Liquid Chromatographic Determination of Diazepam in Tablets: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 545-546
Author(s):  
Michael Tsougros
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Photometric Detection ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
The Mean ◽  
Liquid Chromatographic

Abstract A stability indicating liquid chromatographic method for the determination of diazepam in tablets was collaboratively studied by 6 laboratories. The method uses a Cig reverse phase column, a methanolwater mobile phase, p-tolualdehyde as the internal standard, and photometric detection at 254 nm. The collaborators were supplied with a synthetic tablet powder and 3 commercial tablet samples. The mean recovery of diazepam from the synthetic tablet powder was 100.2%. For all samples analyzed, the coefficient of variation was < 1.5%. The method has been adopted official first action.

Liquid Chromatographic Determination of Triadimefon in Technical and Formulated Products: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 586-589
Author(s):  
Stephen C Slahck
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Normal Phase ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Technical Products

Abstract A liquid chromatographic method for the determination of triadimefon (Bayleton™) in triadimefon technical and formulated products has been developed and subjected to a collaborative study with 7 participating collaborators. Formulations were extracted with mobile solvent and analyzed by normal phase chromatography, with 4-chlorophenyl sulfoxide as an internal standard. Collaborators were furnished with standards and samples of technical products, 50% wettable powders, and 25% wettable powders for analysis. Coefficients of variation of the values obtained on these samples were 1.42, 0.82, and 1.05%, respectively. The method has been adopted official first action.

Liquid Chromatographic Determination of Carbamazepine in Tablets

1988 ◽  
Vol 71 (3) ◽  
pp. 523-525 ◽  
Author(s):  
Ella S Walker
Keyword(s):  
Internal Standard ◽  
Standard Technique ◽  
Chromatographic Determination ◽  
Individual Values ◽  
Qualitative And Quantitative ◽  
Average Value ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple and rapid liquid chromatographic method is described for the qualitative and quantitative determination of carbamazepine in tablet composites and individual tablets, using the internal standard technique. Analyses were performed on a C-18 reverse-phase column with tetrahydrofuran-methanol-water (8 + 37 + 55) as the mobile phase. A linear relationship was obtained between detector responses at 254 nm and amounts of carbamazepine injected ranging from 0.2 to 1.7 ng. The coefficient of variation for 10 consecutive injections of a standard preparation was 0.4%. Recoveries of carbamazepine from 100 and 200 mg tablets averaged 101.4 and 99.7%, respectively. Assay results for commercial tablets analyzed by the proposed method agreed favorably with those obtained by the method of USP XXI. The assay results for individual tablets indicated that deviations from the average value and the range of individual values are much wider with the compendial method than with the proposed method

Gas-chromatographic determination of mephenytoin and desmethylmephenytoin, after off-column alkylation.

1979 ◽  
Vol 25 (1) ◽  
pp. 172-175
Author(s):  
V A Raisys ◽  
A M Zebelman ◽  
S F MacMillan
Keyword(s):  
Active Metabolite ◽  
Chromatographic Method ◽  
Seizure Control ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Therapeutic Concentration ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract We describe a gas-liquid chromatographic method for determining mephenytoin and its active metabolite, desmethylmephenytoin, in human serum. 5-Methyl-5-phenylhydantoin is used as the internal standard. The method involves extraction of the drugs by adsorption onto charcoal and off-column derivatization to their pentyl derivatives. Peak height and concentration are linearly related and the day-to-day CV for therapeutic concentration is about 2 to 6%. No interferences by endogenous compounds or drugs commonly used for seizure control have been encountered.

Improved liquid-chromatographic method for determination of serum cortisol.

1979 ◽  
Vol 25 (7) ◽  
pp. 1293-1296 ◽  
Author(s):  
P M Kabra ◽  
L L Tsai ◽  
L J Marton
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Serum Cortisol ◽  
Peak Height ◽  
Reversed Phase ◽  
Column Temperature ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract We describe a specific and precise method for measuring concentrations of cortisol in serum or plasma by liquid chromatography. Cortisol, together with an internal standard, equilenin, is extracted from 1 mL of serum or plasma and analyzed isocratically on a reversed-phase column with a mobile phase of acetonitrile/phosphate buffer (30/70, by vol.), at a flow rate of 2.0 mL/min. The eluted cortisol is detected by its absorption at 254 nm and quantitated by peak height measurements. Each analysis requires no longer than 15 min at the optimum column temperature of 50 degrees C. The lower limit of detection for cortisol is about 2 ng/sample for a standard solution; sensitivity is routinely 5 micrograms/L of serum. Analytical recoveries exceeded 95%, with good day-to-day precision (coefficients of variation between 4 and 7%). Of more than 50 drugs and steroids tested for possible interference, only the steroids cortisone, prednisone, and prednisolone may interfere with the analysis of cortisol.

Liquid-chromatographic determination of amitryptyline and its metabolites in serum, with adsorption onto glass minimized.

1982 ◽  
Vol 28 (10) ◽  
pp. 2143-2148 ◽  
Author(s):  
P M Edelbroek ◽  
E J de Haas ◽  
F A de Wolff
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Irreversible Adsorption ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract To study correlations between the concentrations, in serum, of amitriptyline and its most important metabolites with clinical response in patients, we developed a "high-performance" liquid-chromatographic method for routine determination of amitriptyline, nortriptyline, total 10-hydroxy-amitriptyline, desmethylnortriptyline, and E(trans)- and Z(cis)-10-hydroxynortriptyline. These compounds are extracted from 1 mL of alkalinized serum into hexane/isoamyl alcohol (99/1 by vol). Perazine is the internal standard. To minimize irreversible adsorption of the drugs onto the glassware, 5 micrograms of maprotiline is added to the organic phase just before evaporation. After a 10-min resolution on a silica column eluted with acetonitrile/methanol/NH4OH (1 mol/L), absorbance is measured at 240 nm. Only chlorimipramine, doxepin, procainamide, and N-acetylprocainamide may interfere with assay of the compounds that probably are therapeutically relevant: amitriptyline, nortriptyline, and E-10-hydroxynortriptyline. Uremia, lipemia, and icterus also do not affect the analysis.

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