Determination of Metsulfuron Methyl and Its Two Metabolites in Crops by Liquid Chromatography with Ultraviolet Detection

1994 ◽  
Vol 77 (6) ◽  
pp. 1654-1659 ◽  
Author(s):  
Mjn Zhou ◽  
Gui-Yun Li ◽  
Stephanie A Whalen
Keyword(s):  
Liquid Chromatography ◽  
Signal To Noise Ratio ◽  
Reversed Phase ◽  
Metsulfuron Methyl ◽  
Sugarcane Stalk ◽  
Simple Extraction ◽  
Oat Straw ◽  
Reversed Phase Lc ◽  
Hydroxy Metabolite

Abstract Metsulfuron methyl, its hydroxy metabolite (A1), and its glucose conjugate metabolite (A) were determined in several crops by liquid chromatography (LC) using a simple extraction and cleanup scheme. After the parent and 2 major metabolites were extracted from crops with methanol, metabolite A was enzymatically hydrolyzed to metabolite A1 with β-glucosidase. The treated extracts were cleaned up chromatographically, and then metsulfuron methyl and metabolite A1 were quantitatively determined by reversed-phase LC with UV detection at 254 nm. Recovery of metsulfuron methyl and its 2 metabolites was 90 ± 6% over a range of 0.005 to 0.4 ppm from fortified samples of brown grain, wheat, barley, sugarcane stalk, and oat straw. Method detection limits (MDLs) were 0.005 ppm for metsulfuron methyl, 0.006 ppm for metabolite A, and 0.003 ppm for metabolite A1 in such crops as brown grain, wheat, barley, and sugarcane, and 0.01 ppm for metsulfuron methyl, 0.015 ppm for metabolite A, and 0.01 ppm for metabolite A1 in oat straw. The MDLs were estimated on the basis of a signal-to-noise ratio of 5 within a confidence interval of 95%. The method has potential application for the analyses of these analytes in other crops and feeds and may be applicable to other sulfonylurea herbicides.

scholarly journals Affinity Liquid Chromatography Method for the Quantification of Immunoglobulin G in Bovine Colostrum Powders

2006 ◽  
Vol 89 (5) ◽  
pp. 1249-1256 ◽  
Author(s):  
David E J Copestake ◽  
Harvey E Indyk ◽  
Don E Otter
Keyword(s):  
Liquid Chromatography ◽  
Immunoglobulin G ◽  
Reversed Phase ◽  
Chromatography Method ◽  
Relative Standard ◽  
Liquid Chromatography Method ◽  
And Performance ◽  
Bovine Immunoglobulin ◽  
Reversed Phase Lc

Abstract An affinity liquid chromatography (LC) method for the determination of bovine immunoglobulin G (IgG), using protein G coupled to an agarose support, was modified to permit the quantification of IgG in colostrum-based powders. Sample preparation included pH adjustment to 4.6 to precipitate casein and denatured whey protein. The method was applied to a range of colostrum powders and was compared with the alternative independent methods of surface plasmon resonance immunoassay, radial immunodiffusion, and reversed-phase LC. The method was rapid, and performance parameters included a working range of 10-150 μg IgG and precision relative standard deviation values of <10%.

scholarly journals Determination of Total Avermectin B1 and 8,9-Z-Avermectin B1 Residues in Wine by Liquid Chromatography

1996 ◽  
Vol 79 (5) ◽  
pp. 1158-1161 ◽  
Author(s):  
Janice A Cobin ◽  
Nelson A Johnson
Keyword(s):  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Reversed Phase ◽  
Liquid Chromatographic Method ◽  
Limit Of Quantitation ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method was developed and validated for determination of avermectin Bi and 8,9-Z-avermectin B1 residues in wine. The sample is extracted with hexane-acetonitrile and the hexane layer containing the avermectins is concentrated/ purified on an aminopropyl solid-phase extraction (SPE) column. The purified extract is derivatized with trifluoroacetic anhydride and the derivatized avermectins are analyzed by reversed-phase liquid chromatography with fluorescence detection. Recoveries of avermectins from wine fortified with approximately 1-25 ng/g avermectin B1a or 8,9-Zavermectin B1a averaged 88 and 102%, respectively. The limit of quantitation is 1 ng/g (signal-to-noise ratio [S/N] > 10) and the limit of detection is 0.5 ng/g (S/N > 3) for each analyte. This procedure provides a simple, rapid, and sensitive method for monitoring the total amount of avermectin residues in wine.

scholarly journals Determination of Norfloxacin and Enrofloxacin by Solid-Phase Microextraction/High-Performance Liquid Chromatography

2008 ◽  
Vol 91 (6) ◽  
pp. 1339-1343 ◽  
Author(s):  
Ashwini Kumar ◽  
Gaurav Dhingra ◽  
Ashok Kumar malik ◽  
Dhananjay K Tewary
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
Solid Phase Microextraction ◽  
High Performance ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Reversed Phase ◽  
Citrate Buffer

Abstract A solid-phase microextraction (SPME) method followed by separation with high-performance liquid chromatography and subsequent UV detection was developed for the determination of norfloxacin and enrofloxacin. The simple and sensitive preconcentration technique uses 280 nm wavelength in mobile phase of citrate buffer (0.01 M), pH 3.8, prepared in water (A) and acetonitrile (B), with composition of the mobile phase A:B, 40:60, at a flow rate of 1.0 mL/min. A C18 reversed-phase analytical column (5 m) was selected as separation medium for the technique. To obtain optimum extraction efficiency, several parameters relating to SPME were investigated. The method was linear over the range of 10100 ng/mL for norfloxacin and enrofloxacin with a correlation coefficient (R2) value of 0.9972 and 0.9980 for norfloxacin and enrofloxacin, respectively. Using the SPME method, the detection limits (signal-to-noise ratio 3) are 0.17 and 0.12 ng/mL for norfloxacin and enrofloxacin, respectively.

Determination of Ticarcillin and Clavulanic Acid in Serum by Liquid Chromatography

1992 ◽  
Vol 75 (1) ◽  
pp. 30-33 ◽  
Author(s):  
Jennifer C Wright ◽  
Carl N Durham ◽  
Jacob R Dunbar
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Clavulanic Acid ◽  
Solid Phase ◽  
Reversed Phase ◽  
Phase Extraction ◽  
Liquid Chromatographic ◽  
Reversed Phase Lc ◽  
Ml Detection

Abstract A liquid chromatographic (LC) method using solidphase extraction for the determination of clavulanic acid and ticarcillin in human serum has been developed. Clavulanic acid and ticarcillin were extracted separately from 1 mL serum using C18 solid-phase extraction cartridges. Eluates were analyzed by the same reversed-phase LC system. The overall mean recovery of clavulanic acid from serum was 99.7 ±2.3%; the lowest level validated in serum was 0.5 μg/mL. The overall mean recovery of ticarcillin from serum was 101.5 ±3%; the lowest level validated in serum was 12.5 μg/mL. Detection limits for clavulanic acid and ticarcillin were 0.117 and 0.749 μg/mL, respectively.

scholarly journals Determination of Residues of Pirimicarb and Its Desmethyl and Desmethylformamido Metabolites in Fruits and Vegetables by Liquid Chromatography–Electrospray/Mass Spectrometry

2000 ◽  
Vol 83 (3) ◽  
pp. 735-741 ◽  
Author(s):  
James R Startin ◽  
Mark D Sykes ◽  
John C Taylor ◽  
Simon J Hird ◽  
Kirsty Jackson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Electrospray Mass Spectrometry ◽  
Fruits And Vegetables ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Reversed Phase ◽  
Green Beans ◽  
Broad Beans

Abstract A method was developed for the simultaneous determination of residues of pirimicarb (I) and its desmethylformamido (II) and desmethyl (III) metabolites in plums, peas, green beans, broad beans, carrots, and swedes. The compounds were extracted with ethyl acetate and determined, without cleanup, by reversed-phase liquid chromatography and electrospray mass spectrometry (MS). MS and MS/MS were used concurrently to monitor the protonated molecules and their common collision-induced dissociation product. The limit of detection (signal-to-noise ratio of >3) was 1 ng/mL, corresponding to crop concentrations of <0.0015 mg/kg. All 3 compounds were determined in plums, broad beans, and green beans by MS without interference. Interferences which affected the determination of desmethylformamido-pirimicarb in peas, and to a lesser extent in carrots and swedes, were eliminated by MS/MS. Recoveries for all 3 compounds, at 0.05 mg/kg for plums and 0.005 mg/kg for other commodities, were in the range 83–124%. No interconversion of I, II and III, occurred during extraction, and the compounds were stable in extracts for ≥7 days under appropriate conditions.

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