Ion-Pairing Liquid Chromatographic Determination of Benzimidazole Fungicides in Foods

1990 ◽  
Vol 73 (5) ◽  
pp. 753-761 ◽  
Author(s):  
Dalia M Gilvydis ◽  
Stephen M Walters
Keyword(s):  
Mobile Phase ◽  
Ion Pairing ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Benzimidazole Fungicides ◽  
Reverse Phase Liquid Chromatography ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A method Is described for determining residues in foods of thiabendazole, thlophanate methyl, the dl-oxygen analogue metabolite [dimethyl 4,4'-0-phenylene bis (allophanate)] that Is the metabolite name of the latter, and methyl-2- benzlmldazole carbamate, which Is the major metabolite and fungltoxlc principle common to both thlophanate methyl and benomyl. The residues are extracted from the product using methanol and are partitioned Into dlchloromethane after initial acidification and again after subsequent alkalinization of the extract. Residues are separated and quantified by reverse- phase liquid chromatography using an ion-pairing mobile phase with UV and fluorescence detectors In tandem. Recoveries from 7 different food crops fortified at 0.2-35 ppm levels ranged from 64 to 105%.

Liquid Chromatographic Determination of Fluridone Aquatic Herbicide and Its Metabolite in Fish and Crayfish

1986 ◽  
Vol 69 (5) ◽  
pp. 856-859 ◽  
Author(s):  
Sheldon D West ◽  
Edgar W Day
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Aquatic Herbicide ◽  
Liquid Chromatographic

Abstract A residue method is described for determination of the aquatic herbicide fluridone (1-methy1-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)- pyridinone) and its metabolite (1-methy1-3-(4-hydroxyphenyl)-5-[3- (trifluoromethyl)phenyl]-4(1H)-pyridinone) in fish and crayfish tissues. Both compounds are extracted from tissues with methanol, and the extracts are subjected to acidic hydrolysis to release conjugated forms of fluridone and the metabolite. Sample extracts are purified by liquidliquid partitioning and Florisil Sep-Pak® column chromatography. Both compounds are separated and measured by reverse phase liquid chromatography with UV detection at 313 nm. In the absence of interfering peaks, the method has a detection limit of approximately 0.04 ppm of either compound. Overall, recoveries averaged 96% for fluridone and 78% for the metabolite for all tissue types combined.

Liquid Chromatographic Determination of Major Alkaloids in Gum Opium

1985 ◽  
Vol 68 (4) ◽  
pp. 801-803
Author(s):  
Vinod K Srivastava ◽  
Mohan L Maheshwari
Keyword(s):  
Mobile Phase ◽  
Sodium Acetate ◽  
Chromatographic Determination ◽  
Aqueous Acetic Acid ◽  
Reverse Phase ◽  
Qualitative And Quantitative ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract An isocratic reverse phase liquid chromatographic (LC) system has been developed for qualitative and quantitative assay of morphine, codeine, thebaine, papaverine, and narcotine in gum opium. Five extractions with 2.5% aqueous acetic acid quantitatively extracted the major alkaloids. A mixture of 1% aqueous sodium acetate (pH 6.78), acetonitrile, and 1,4-dioxane (75 + 20 + 5) is used as LC mobile phase | for better resolution of alkaloid peaks, especially those of morphine and codeine. The method is suitable for routine analysis of gum opium I samples.

Liquid Chromatographic Determination of Cholecalciferol m Rodent Baits

1987 ◽  
Vol 70 (6) ◽  
pp. 1058-1059
Author(s):  
Connie C Gehrig ◽  
Rodger W Stringham
Keyword(s):  
Vitamin D3 ◽  
Correlation Coefficients ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract Cholecalciferol (vitamin D3) is extracted In acetonitrile on a Goldfisch apparatus, diluted to volume, and determined by reverse phase liquid chromatography (LC). The sum of the peak heights of pre-vitamin D3, and cfr-vitamin D3, is used for quantitation. The method was tested for precision, linearity, and recovery. Quadruplicate analyses of 5 formulation samples gave relative standard deviations of 1.56- 2.65%. Linearity was excellent with regression and correlation coefficients of 0.9997 and 0.9998, respectively. Recovery was 98.0 ± 2.7%. The method is applicable to 0.075% cholecalciferol rodent baits.

Liquid Chromatographic Determination of Bromadiolone in Rodent Baits

1990 ◽  
Vol 73 (3) ◽  
pp. 429-430
Author(s):  
Benny Koppen
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Relative Standard ◽  
Peak Areas ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A method Is described for the determination of bromadiolone in rodent bait formulations. Samples are Soxhlet-extracted using methanol as extractant and analyzed by reverse-phase liquid chromatography with UV detection at 280 nm. Chromatography is performed using a ODS-Hypersll (5 fim) column, which enables separation of the 2 diastereolsomers of bromadlolone. The sum of the peak areas of the diastereolsomers Is used for quantitation. The method was tested for precision, linearity, and recovery. Duplicate analyses of 10 formulation samples gave a mean relative standard deviation of 4.1%. Linearity was very good (correlation coefficient 0.9997) In the relevant concentration range. Recovery from spiked samples was 88.9 ±2.3%. The method is applicable to rodent bait formulations with bromadiolone content 0.005% and 0.01%.

Rapid Liquid Chromatographic Determination of Patulin in Apple Juice

1985 ◽  
Vol 68 (5) ◽  
pp. 950-951 ◽  
Author(s):  
Pedro Rafael Forbito ◽  
Norma Elena Babsky
Keyword(s):  
Liquid Chromatography ◽  
Apple Juice ◽  
Sodium Carbonate Solution ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A rapid method is described for the quantitative determination of patulin in apple juice. The mycotoxin is extracted from the sample with ethyl acetate and the extract is cleaned up by extraction with a sodium carbonate solution. Patulin is determined by reverse phase liquid chromatography using a μ.Bondapak C18covery is >75%.

Reverse Phase Liquid Chromatographic Determination of Aspartame in Beverages and Beverage Mixes

1984 ◽  
Vol 67 (3) ◽  
pp. 510-513 ◽  
Author(s):  
Norma G Webb ◽  
Darrell D Beckman
Keyword(s):  
Mobile Phase ◽  
Isopropyl Alcohol ◽  
Chromatographic Determination ◽  
Artificial Sweetener ◽  
Reverse Phase ◽  
Acetic Acid Water ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A method is described for determining the artificial sweetener aspartame in beverages and beverage mixes by liquid chromatography. Aspartame is separated on a μC18 column, using a mobile phase of acetic acid, water, and isopropyl alcohol at pH 3.0 and UV detection at 254 nm. Beverages are filtered through 0.45 μm filters and injected directly into the chromatograph. Aspartame is eluted in approximately 7 min. Detection of aspartame is confirmed by a UV scan of the trapped peak. Aspartame is quantitated in the presence of other beverage additives such as saccharin, caffeine, sodium benzoate, artificial colors, and artificial flavors. Results are presented for spiked soda beverages, beverages from fruit-flavored mixes, instant tea, reconstituted presweetened drink mixes, and a powdered tabletop sweetener.

Liquid Chromatographic Determination of Vitamin D in Infant Formula

1989 ◽  
Vol 72 (6) ◽  
pp. 1007-1009
Author(s):  
Vipin K AGARWAL
Keyword(s):  
Vitamin D ◽  
Infant Formula ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Total Vitamin ◽  
Reverse Phase Liquid Chromatography ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A method is described for the determination of vitamins D2 + D3 in milk- and soy-based infant formula. Vitamins D2 and D3 are extracted from the saponified sample and converted to isotachysterols with acidified butanol. Reverse-phase liquid chromatography (LC) is used to remove interferences, and total vitamin D is quantitated using normal-phase LC. Recoveries of spiked samples averaged 97.6% for milk-based infant formula, and 98.8% for soy-based infant formula. This method quantitates vitamin D2 + D3 in infant formulas containing as low as 40 IU/qt when prepared according to label direction

Effects of Injection Solvent and Mobile Phase on Efficiency in Reverse-Phase Liquid Chromatographic Determination of Aflatoxin M1

1990 ◽  
Vol 73 (1) ◽  
pp. 69-70 ◽  
Author(s):  
Rodney W Beaver
Keyword(s):  
Mobile Phase ◽  
Chromatographic Determination ◽  
Aflatoxin M1 ◽  
Mobile Phase Composition ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Theoretical Plates

Abstract The effects of Injection solvent and mobile phase composition on the reverse-phase liquid chromatographic determination of aflatoxin M1 (M1) were examined. M1 was converted to the more highly fluorescent derivative aflatoxin M2a (M2a)- Using a C-18 column and a mobile phase of H20-MeCNMeOH (60 + 20 + 20) (MP-A), M2a was dissolved in various ratios of MeCN-H20 prior to Injection. Chromatographic efficiency for the M2a peak varied from ca 2000 theoretical plates when injected in 30% aqueous MeCN to ca 9000 plates when injected in water alone. However, using the same C-18 column but with a mobile phase of H20-IPAMeCN (80 + 12 + 8) (MP-B), the M2a peak exhibited 25000 plates when injected in 30% aqueous MeCN and 10000 plates when injected in water alone.

Liquid Chromatographic Determination of Residual Styrene in Polystyrene Food Packaging

1981 ◽  
Vol 64 (3) ◽  
pp. 647-652
Author(s):  
Sandra L Varner ◽  
Charles V Breder
Keyword(s):  
Mobile Phase ◽  
Food Packaging ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Plastic Containers

Abstract The determination of residual styrene in polystyrene food packaging polymers by a reverse phase liquid chromatographic method is described. The polymer is dissolved in tetrahydrofuran and then reprecipitated with methanol. The filtered solution is chromatographed by using an aqueous tetrahydrofuran mobile phase, and the styrene is detected and quantitated by ultraviolet at 254 nm. The detection limit for the method is about 0.5 ppm styrene on a solution basis and 20 ppm in the polymer. The average recovery of styrene from spiked polymer (about 50–3700 ppm) is 88%. Apparent residual styrene was determined in several commercial products, including rigid polystyrene cups, flexible plastic containers, and several foam products. The monomer levels ranged from about 60 to 2250 ppm.

Analysis of Pharmaceutical Dosage Forms for Oxfendazole: I. Reverse Phase Liquid Chromatographic Determination of Oxfendazole in Swine Premix

1986 ◽  
Vol 69 (1) ◽  
pp. 20-24
Author(s):  
Jeffrey Fleitman ◽  
Daniel Neu ◽  
Gary Visor
Keyword(s):  
Mobile Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Organic Content ◽  
Reverse Phase ◽  
Pharmaceutical Dosage Forms ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A reverse phase liquid chromatographic (LC) procedure is described for quantitating oxfendazole (2-(methoxycarbonylamino)-5-phenyIsuIfinylbenzimidazole)) in swine premix. Sample preparation consists of extracting oxfendazole with an acetone-methanol mixture. An aliquot of the extract is then centrifuged to separate undissolved premix excipients. Internal standard is added to the supernate and the sample is further diluted with water-acetonitrile-phosphoric acid (80 + 20 + 1). Oxfendazole is quantitatively determined using a Partisil-5-ODS-3 column with acetonitrile-O.OlM phosphate buffer (pH 6.0) as the mobile phase. The method is stability specific and yields a mean recovery of 101.1 ± 0.4% for the 1.35% premix formulation. The dependence of chromatographic performance characteristics on mobile phase organic content, pH, and buffer concentration is also reported.

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