High Pressure Liquid Chromatographic Determination of 3,5-Dimethyl-4-(Methylthio) phenyl Methylcarbamate in Formulations

1979 ◽  
Vol 62 (1) ◽  
pp. 5-7
Author(s):  
Martha Fuzesi
Keyword(s):  
High Pressure ◽  
Quantitative Measurement ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Pesticide Formulations ◽  
Liquid Chromatographic Determination ◽  
Commercial Pesticide ◽  
Liquid Chromatographic

Abstract Methiocarb (3,5 - dimethyl - 4 - (methylthio) - phenyl methylcarbamate) is extracted from commercial pesticide formulations with methanol, and carbaryl is added as an internal standard. The sample is chromatographed by reverse phase high pressure liquid chromatography, with ultraviolet detection at 254 nm. Peak height ratios are used for quantitative measurement. The method is rapid and accurate, and recoveries from laboratory-prepared formulations averaged 100.8%.

High Pressure Liquid Chromatographic Determination of Difenzoquat in Formulations

1980 ◽  
Vol 63 (3) ◽  
pp. 647-649
Author(s):  
Carla Barry ◽  
Richard K Pike
Keyword(s):  
High Pressure ◽  
Quantitative Measurement ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Pressure Liquid Chromatographic ◽  
Pesticide Formulations ◽  
Liquid Chromatographic Determination ◽  
Commercial Pesticide ◽  
Liquid Chromatographic

Abstract Difenzoquat (l,2-dimethyl-3,5-diphenylpyrazolium ion) as its methyl sulfate is extracted from commercial pesticide formulations with acetonitrile-water (1+), with acetophenone added as internal standard. The sample is chromatographed by reverse phase high pressure liquid chromatography with ultraviolet detection at 280 nm. Peak area ratios are used for quantitative measurement. The method is simple, rapid, and direct, and its applicability to other quaternary ammonium herbicides is discussed.

Gas-Liquid Chromatographic Determination of Pentachloronitrobenzene in Pesticide Formulations

1976 ◽  
Vol 59 (3) ◽  
pp. 708-710
Author(s):  
Alan R Hanks ◽  
Christine W Cramer
Keyword(s):  
Chromatographic Method ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Liquid Chromatographic Method ◽  
Pesticide Formulations ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method has been developed to determine pentachloronitrobenzene (PCNB) in pesticide formulations including dusts, powders, granules, liquids, and fertilizers. Captan, disulfoton, and Terrazole do not interfere. Samples are extracted with chloroform, and an aliquot is mixed with an equal volume of internal standard solution containing o-terphenyl. PCNB is chromatographed on a 5% SE-30 column and quantitated by peak height ratios. The method has been subjected to a ruggedness test which indicates little sensitivity to changes in extraction and chromatographic conditions.

High Pressure Liquid Chromatographic Determination of Phenol in Honey

1981 ◽  
Vol 64 (2) ◽  
pp. 337-339
Author(s):  
Peter Sporns
Keyword(s):  
High Pressure ◽  
Mobile Phase ◽  
Silicic Acid Column ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method is described for determining phenol in honey by using high pressure liquid chromatography (HPLC). An internal standard, 2-phenylethanol, was added to honey which was steam-distilled and chromatographed on a 25 cm × 3.2 mm id Spherisorb 5 µm silicic acid column using water as the mobile phase. Absorbance was monitored at 195 nm. Using a mixed standard of known concentration and peak height measurements, the amount of phenol in the honey could be quantitated. Recovery of added phenol was checked at levels from 0.1 to 33 ppm.

Ultraviolet Detection Procedure for Liquid Chromatographic Determination of Indole in Shrimp

1981 ◽  
Vol 64 (3) ◽  
pp. 603-606 ◽  
Author(s):  
Theodore L Chambers ◽  
Walter F Staruszkiewicz
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Ultraviolet Detection ◽  
Carbonate Buffer ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract In an ultraviolet detection procedure, indole was extracted from shrimp by blending with carbonate buffer and then partitioned into ethyl acetate. Before quantitation by high pressure liquid chromatography (HPLC), interferences were removed by the use of a polyamide cleanup column. Concentrated column effluent was injected into the chromatograph. Indole was detected by monitoring absorbance at 217 nm and quantitated by comparison of indole peak height to that of an internal standard, 2-methylindole. Recoveries of indole ranged from 72 to 117%. Results agreed well with those by the official AOAC gasliquid chromatographic (GLC) method.

High Pressure Liquid Chromatographic Determination of Theobromine and Caffeine in Cocoa and Chocolate Products: Collaborative Study

1980 ◽  
Vol 63 (3) ◽  
pp. 591-594
Author(s):  
Wesley R kreiser ◽  
Robert A Martin ◽  
◽  
R Bigornia ◽  
R Bond ◽  
...  
Keyword(s):  
High Pressure ◽  
Petroleum Ether ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Peak Height ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
The Mean ◽  
Liquid Chromatographic

Abstract Four duplicate samples of cocoa-containing materials, a practice sample, and standards were submitted to the collaborators for theobromine and caffeine analysis by HPLC. In the method the samples are defatted with petroleum ether, and dried. The fat-free residue is then extracted with water and an aliquot is injected into the chromatograph. Compounds are quantitated by comparison with internal or external standards, either by peak height or peak area. Results for all the analyses showed that few of the values were more than 2 standard deviations from the mean. The method has been adopted as official first action.

Gas-Liquid Chromatographic Determination of Phenothiazine in Medicated Feeds

1973 ◽  
Vol 56 (1) ◽  
pp. 174-176
Author(s):  
Billy M Colvin ◽  
Albert E Prudom ◽  
Larry L Whitlock ◽  
Alan R Hanks
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Good Precision ◽  
Gas Chromatograph ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Medicated Feeds

Abstract A simple and rapid method is described for the determination of phenothiazine in feeds. Phenothiazine is extracted with chloroform containing chlorobenzilate as an internal standard. The extract is injected into a gas chromatograph and peak height ratios are used for quantitation. The analysis of commercial samples shows that the method compares well with the more commonly employed colorimetric AOAC method, and good precision, with recoveries ranging from 96.0 to 99.9%, is obtained in the analysis of prepared samples.

High Pressure Liquid Chromatographic Determination of Physostigmine Salicylate and Physostigmine Sulfate in Liquids and Ointments: Collaborative Study

1982 ◽  
Vol 65 (1) ◽  
pp. 132-137
Author(s):  
Norlin W Tymes ◽  
◽  
G Briguglio ◽  
C Corcoran ◽  
R Everett ◽  
...  
Keyword(s):  
High Pressure ◽  
Collaborative Study ◽  
Internal Standard ◽  
Pharmaceutical Formulations ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Results of 11 laboratories are presented for the collaborative study of a proposed method for the quantitative reverse phase high pressure liquid chromatographic (HPLC) determination of physostigmine salicylate and physostigmine sulfate in pharmaceutical formulations. The samples consisted of commercial solution, injection, and ointment preparations, each containing one of the physostigmine salts. The physostigmine salt is extracted from ointments with acetonitrile after the ointment is dissolved in hexane. Liquid preparations are diluted directly. Physostigmine is determined at 254 nm on a C18 column by comparison with a physostigmine standard. Flurazepam hydrochloride is the internal standard. The method has been adopted official first action for the solution dosage form.

Gas-Liquid Chromatographic Determination of Naled in Pesticide Formulations

1975 ◽  
Vol 58 (6) ◽  
pp. 1162-1168
Author(s):  
A Aner Carlstrom
Keyword(s):  
Dibutyl Phthalate ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Pesticide Formulations ◽  
Wide Range ◽  
Technical Material ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Column Packings

Abstract Dusts, emulsions, concentrates, and technical material covering a wide range (1%92%) of naled were diluted or extracted with chloroform. Dibutyl phthalate was added to sample extracts as an internal standard before gas-liquid chromatographic (GLC) injection. Twelve column packings covering the entire polarity scale were tested, and 3% XE-60 was chosen, based on the best resolution for a difficult-to-separate low volume concentrate. Response is linear from 1 to 50 mg naled/ml and the coefficient of variation for the GLC step is 0.81%. Of 29 other active ingredients which have been formulated with naled, diazinon and 1 isomer of BHC elute with naled, while dicrotophos elutes with the internal standard.

Reverse Phase High Pressure Liquid Chromatographic Determination of Arprinocid in Animal Feeds

1982 ◽  
Vol 65 (1) ◽  
pp. 43-47
Author(s):  
Virginia A Thorpe
Keyword(s):  
High Pressure ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Simple Method ◽  
Working Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple method is presented for determination of arprinocid in finished feeds by reverse phase high pressure liquid chromatography. The sample is extracted with 95% DMF, the major feed interferences are removed by alumina chromatography, and arprinocid is separated from the remaining interferences on the HPLC column. The peak height detected at 254 nm can be quantitated by direct comparison with the working standard.

Simultaneous high-pressure liquid-chromatographic determination of some anticonvulsants in serum.

1976 ◽  
Vol 22 (1) ◽  
pp. 25-31 ◽  
Author(s):  
R F Adams ◽  
F L Vandemark
Keyword(s):  
High Pressure ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Serum Samples ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Peak Areas ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe procedures for simultaneously determining some anticonvulsants (phenobarbital, diphenylhydantoin, primidone, ethosuximide, methsuximide, carbamazepine) in serum by high-pressure liquid chromatography. The drugs, together with an internal standard, phenacetin, are adsorbed from serum onto charcoal and eluted from it with organic solvent. The eluate is analyzed isocratically on a reverse-phase column with a mobile phase consisting of acetonitrile/water (17/83 by volume). The eluted drugs are detected by their absorption at 195 nm, and quantities estimated from their peak areas as compared with those of extracted standards. Results are reproducible to about 6%. Sensitivities, for 0.5-ml serum samples, of 0.1 mg/liter for all the drugs analyzed except ethosuximide (0.5 mg/liter) are attained routinely. Correlation of results with gas chromatography was 0.912 for phenobarbital, 0.982 for diphenylhydantoin, 0.886 for primidone, and 0.966 for ethosuximide. Amobarbital and secobarbital interfere with the analysis; chlordiazepoxide, methaqualone, salicylate, diazepam, and oxazepam do not. Including extraction, analysis time for a single sample is 20 min.

Sign in / Sign up

Export Citation Format

Share Document