Liquid Chromatographic Determination of Simazine, Atrazine, and Propazine Residues in Catfish

1995 ◽  
Vol 78 (4) ◽  
pp. 1067-1071 ◽  
Author(s):  
David C Holland ◽  
Robert K Munns ◽  
José E Roybal ◽  
Jeffrey A Hurlbut ◽  
Austin R Long
Keyword(s):  
Ethyl Acetate ◽  
Petroleum Ether ◽  
Simultaneous Determination ◽  
Mobile Phase ◽  
Chromatographic Determination ◽  
Triazine Herbicides ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method is described for the simultaneous determination of the triazine herbicides, simazine (SIM), atrazine (ATZ), and propazine (PRO) in the 12.5–100 ppb range in catfish. The herbicides are extracted from catfish homogenates with ethyl acetate, followed by solvent partitioning between acetonitrile and petroleum ether and additional cleanup on a C18 cartridge. A Supelcosil LC-18-DB column is used for LC separation, and UV determination is at 220 nm. The isocratic mobile phase is a mixture of methanol, acetonitrile, and water. Mean recoveries from catfish were 88.7, 96.9, and 91.7%; standard deviations were 6.84,7.78, and 6.26%; and coefficients of variation were 7.72,8.03, and 6.82% for SIM, ATZ, and PRO, respectively.

scholarly journals Liquid Chromatographic Determination of Mebendazole and its Metabolites, Aminomebendazole and Hydroxymebendazole, in Eel Muscle Tissue

1996 ◽  
Vol 79 (3) ◽  
pp. 645-651 ◽  
Author(s):  
Christiaan A J Hajee ◽  
Nel Haagsma
Keyword(s):  
Muscle Tissue ◽  
Mobile Phase ◽  
Solid Phase ◽  
Chromatographic Determination ◽  
Extraction Column ◽  
Phase Extraction ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract An analytical method is presented for liquid chromatographic (LC) determination of mebendazole (MBZ), hydroxymebendazole (MBZ-OH), and aminomebendazole (MBZ-NH2) in eel muscle tissue. Muscle tissue is extracted with ethyl acetate at pH 7.5. After addition of n-hexane, the extract is cleaned up and concentrated on an aminopropyl solid-phase extraction column. The test solutions are analyzed isocratically on a ChromSpher B LC column with acetonitrile–phosphate buffer, pH 6.2, as mobile phase. Limits of detection and quantitation were 0.7 and 1.1 ¼g/kg, respectively, for MBZOH; 1.4 and 2.3 ¼g/kg, respectively, for MBZ; and 1.5 and 2.1 ¼g/kg, respectively, for MBZ-NH2. Interand intraday coefficients of variation were 3.5 and 3.4%, respectively, for MBZ-OH; 2.5 and 3.1%, respectively, for MBZ; and 5.8 and 4.8%, respectively, for MBZ-NH2. Mean recoveries were 90% for MBZ, 74% for MBZ-NH2, and 92% for MBZ-OH. A linear range of applicability of at least 10–1000 ¼g/kg was found for each analyte. Incurred MBZ-NH2 (181.3 ¼g/kg) was identified in eel muscle tissue apart from MBZ (23.7 ¼g/kg) after 48 h exposure ina treatment bath containing MBZ at 1 mg/L.

Liquid Chromatographic Determination of Primidone in Tablets: Collaborative Study

1985 ◽  
Vol 68 (1) ◽  
pp. 85-87 ◽  
Author(s):  
Stanley E Roberts
Keyword(s):  
Quantitative Determination ◽  
Mobile Phase ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Six laboratories collaboratively studied a liquid chromatographic (LC) method for the quantitative determination of primidone in tablets. Two lots each of commercially prepared 50 and 250 mg tablets and 2 authentic mixtures, at 50 and 250 mg levels, were sent to each collaborator. Samples were dissolved in the mobile phase, filtered, and injected into the chromatograph. Average recoveries for the 8 samples ranged from 97.5 to 101.2%, and coefficients of variation ranged from 0.53 to 3.01%. The LC method has been adopted interim official first action.

Simultaneous Liquid Chromatographic Determination of Some Tetracyclines in Serum

1986 ◽  
Vol 69 (5) ◽  
pp. 760-762
Author(s):  
Krystyna Tyczkowska ◽  
Arthur L Aronson
Keyword(s):  
Molecular Weight ◽  
Mobile Phase ◽  
Chromatographic Determination ◽  
Molecular Weight Cutoff ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A sensitive liquid chromatographic method has been developed for the simultaneous determination of oxytetracycline, minocycline, tetracycline, and doxycycline in serum. A serum sample is vortex-mixed with a solution of mobile phase for tetracyclines and 2% (v/v) phosphoric acid. The mixture is filtered using a 30 000 molecular weight cutoff microseparation tube which separates high-molecular-weight solutes following low-speed centrifugation. Tetracyclines are separated from other serum components by reverse phase liquid chromatography (LC) with buffered methanol mobile phase. Ultraviolet absorbance of the column effluent is monitored at 267 nm. Concentrations as low as 0.2 μg/mL of tetracyclines in serum are quantitatable, with recoveries from 76.2 to 102.6% and coefficients of variation from 2.69 to 5.36%. The method has been tested in bovine, porcine, equine, caprine, ovine, canine, feline, and avian (turkey) serum.

Liquid Chromatographic Determination of Acetic Acid in Foods

1984 ◽  
Vol 67 (5) ◽  
pp. 885-887
Author(s):  
Samy H Ashoor ◽  
Jim Welty
Keyword(s):  
Acetic Acid ◽  
Flow Rate ◽  
Mobile Phase ◽  
Chromatographic Determination ◽  
Uv Detector ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method has been developed for the determination of acetic acid in vinegar and other foods. The LC system includes an Aminex HPX-87H column and a UV detector set at 210 nm. The mobile phase is 0.009N H2S04 at a flow rate of 0.7 mL/min. The method is simple and specific for acetic acid. Recoveries of acetic acid from a variety of products ranged from 93.3 to 102% with coefficients of variation from 2.4 to 4.6%.

High Performance Liquid Chromatographic Determination of Caffeine in Decaffeinated Coffee, Tea, and Beverage Products

1983 ◽  
Vol 66 (3) ◽  
pp. 606-609 ◽  
Author(s):  
Samy H Ashoor ◽  
George J Seperich ◽  
Woodrow C Monte ◽  
Jim Welty
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Uv Detector ◽  
Coefficients Of Variation ◽  
Decaffeinated Coffee ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method was developed for determining caffeine in decaffeinated coffee, tea, and beverage products by high performance liquid chromatography (HPLC). The HPLC system consisted of a Bio-Sil ODS-5S C18 column, methanol-water (25 + 75) mobile phase at 1 mL/min, and a UV detector. The method is simple and specific. Caffeine recoveries were 93.8-98.3% and coefficients of variation were 0.90-2.25%.

Simultaneous Liquid Chromatographic Determination of Rotenone and Pyrethrins in Formulations

1985 ◽  
Vol 68 (3) ◽  
pp. 580-582
Author(s):  
Rodney J Bushway ◽  
Harold Johnson ◽  
Donald W Scott
Keyword(s):  
Mobile Phase ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Coefficients Of Variation ◽  
Pesticide Formulations ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Inactive Ingredients ◽  
Liquid Chromatographic

Abstract This paper describes a reverse phase liquid chromatographic (LC) method to simultaneously determine rotenone and pyrethrins in pesticide formulations. The mixed standards along with the formulations were accurately weighed to contain approximately 200 (μg rotenone and 150 (μg pyrethrins/mL. Stabilized tetrahydrofuran was used to dissolve all substances. An aliquot was injected into the LC system equipped with a Zorbax ODS column, and chromatographed with a mobile phase of acetonitrile-water (70 + 30). Rotenone and the pyrethrins were monitored at 240 nm and 0.4 AUFS. Retention times for rotenone, pyrethrin II, and pyrethrin I were approximately 7, 11.5, and 25.5 min, respectively. For 3 different formulations analyzed 6 times each, the percent coefficients of variation were all < 3. This method is also applicable to products containing either rotenone or pyrethrins. No significant interferences were observed from the inactive ingredients of the formulations at the concentrations added.

scholarly journals Liquid Chromatographic Determination of Inositol Hexanicotinate in Formulated Preparations

1997 ◽  
Vol 80 (4) ◽  
pp. 762-766
Author(s):  
Mythili Nagarajan ◽  
Ted W Waszkuc ◽  
Jidong Sun
Keyword(s):  
Dimethyl Sulfoxide ◽  
Correlation Coefficient ◽  
Calibration Curve ◽  
Mobile Phase ◽  
Chromatographic Determination ◽  
Coefficients Of Variation ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A precise and selective liquid chromatographic procedure for determining inositol hexanicotinate (IHN) in formulated preparations was developed and validated. IHN was dissolved in dimethyl sulfoxide, diluted with acetonitrile, chromatographed on a Nova-Pak C18 column with a mobile phase of water-methanol (40 + 60, v/v), and detected at 262 nm. The correlation coefficient of the calibration curve was 0.9995 over the range 0.050.15 mg/mL. Overall recovery of IHN was >97%. Coefficients of variation for intra- and interday precisions were <2%.

Collaborative Study of the Quantitative Gas-Liquid Chromatographic Determination of Fusel Oil and Other Components in Whisky

1972 ◽  
Vol 55 (3) ◽  
pp. 549-556
Author(s):  
J H Kahn ◽  
E T Blessinger
Keyword(s):  
Ethyl Acetate ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Official Method ◽  
Fusel Oil ◽  
Fusel Alcohols ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Fifteen chemists participated in a collaborative study for the quantitative pas-liquid chromatographic determination of the individual fusel alcohols and ethyl acetate in whisky. Two levels of congeners represented by 4 coded samples of whisky were analyzed by using t h e proposed method, employing a glycerol-1,2,6-hexanetriol column, and the official AOAC method, 9.063-9.065. Since isobutyl and the atnyl alcohols comprise by far the greatest part of fusel oil, their determination is of major importance to the total fusel oil content . Statistical analyses show that the proposed method is superior to the AOAC method for the determination of these alcohols, whereas the official method is superior for the determination of ethyl acetate and n-propyl alcohol. In general, collaborators employing modern instrumentation preferred the proposed method over the AOAC method. The former method also separates and permits the quantitative measurement of active amyl and isoamyl alcohols. The proposed method has been adopted as official first action as an alternative to 9.063–9.065 for the determination of higher alcohols and ethyl acetate in whisky.

Improved liquid-chromatographic determination of haloperidol in plasma.

1984 ◽  
Vol 30 (7) ◽  
pp. 1228-1230 ◽  
Author(s):  
A K Dhar ◽  
H Kutt
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Room Temperature ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract This method for determination of haloperidol in plasma is based on "high-performance" isocratic liquid chromatography with the use of a C8 bonded reversed-phase column at room temperature. Haloperidol and the internal standard (chloro-substituted analog) are extracted from alkalinized plasma into isoamyl alcohol/heptane (1.5/98.5 by vol) and back-extracted into dilute H2SO4. The aqueous phase is directly injected onto the column. The mobile phase is a 30/45/25 (by vol) mixture of phosphate buffer (16.5 mmol/L, pH 7.0), acetonitrile, and methanol. Unlike other liquid-chromatographic procedures for haloperidol, commonly used psychotropic drugs do not interfere. Analysis can be completed within an hour. The procedure is extremely sensitive (1.0 microgram/L) and is well reproducible (CV 5.6% for a 2.5 micrograms/L concentration in plasma).

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