Determination of DiazaCon in Quail Feed and Quail Serum by Ion Pair Reversed-Phase Chromatography

Abstract Liquid chromatographic (LC) methods were developed for quantitating the potential avian contraceptive DiazaCon in quail feed and serum. DiazaCon was extracted from ground quail feed with basic n-butyl chloride. The n-butyl chloride extract was evaporated to dryness. The DiazaCon residues were dissolved in an aqueous methanolic ion pairing solution and quantitated by LC at 206 nm. Avian sera was combined with an equal volume of a pH 4 aqueous solution of ion pairing reagent and filtered to remove interfering proteins. DiazaCon was quantitated by LC. Mean recoveries for 500 and 2000 ppm fortified feed were 89.1 and 91.0%, respectively. The mean recovery for sera fortified at 5 levels ranging from 35 to 2000 ppm was 84.9%. Method limits of detection were approximately 14 and 13 ppm for feed and sera, respectively.

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Reversed-Phase Ion-Pair Liquid Chromatographic Determination of Chlorophacinone and Diphacinone in Steam- Rolled Oat Baits and Steam-Rolled Oat/Wax Baits

Journal of AOAC International ◽

10.1093/jaoac/81.2.349 ◽

1998 ◽

Vol 81 (2) ◽

pp. 349-358 ◽

Cited By ~ 8

Author(s):

Thomas M Primus ◽

Doreen L Griffin ◽

Stephanite A Volz ◽

John J Johnston

Keyword(s):

Petroleum Ether ◽

Ion Pairing ◽

Chromatographic Determination ◽

Reversed Phase ◽

Liquid Extraction ◽

Ion Pair ◽

Limits Of Detection ◽

Liquid Chromatographic Determination ◽

Liquid Chromatographic

abstract A reversed-phase ion-pair liquid chromatographic (LC) method was developed for analysis of steam-rolled oat (SRO) baits fortified with either chlorophacinone or diphacinone. Baits were prepared with and without paraffin wax. Chlorophacinone or diphacinone was extracted from wax-free SRO baits with 5 mM tetrabutylammonium phosphate methanolic ion-pairing solution. Wax baits were initially extracted with petroleum ether and then cleaned up by liquid extraction into methanolic ion-pairing solution containing 20% water. SRO extracts were analyzed with reversed-phase ion-pair LC. Chlorophacinone and diphacinone were quantified by UV absorption at 325 nm. Recoveries from SRO fortified with chlorophacinone at 25 and 150 μg/g were 90.7 and 90.8%, respectively, whereas for diphacinone at the same levels, recoveries were 93.5 and 92.3%, respectively. Recoveries from wax baits fortified at 25 and 75 μg/g chlorophacinone were 98.5 and 100%, respectively, whereas for diphacinone at the same levels, recoveries were 93.6 and 98.0%, respectively. Method limits of detection for chlorophacinone and diphacinone in SRO baits were estimated to be 1.0 and 0.76 μg/g, respectively. Method limits of detection for chlorophacinone and diphacinone in wax baits were estimated to be 4.2 and 2.8 μg/g, respectively.

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Simultaneous Liquid Chromatographic Determination of Thiamine and Riboflavin in Selected Foods

Journal of AOAC International ◽

10.1093/jaoac/76.5.1156 ◽

1993 ◽

Vol 76 (5) ◽

pp. 1156-1160 ◽

Cited By ~ 29

Author(s):

Art Sims ◽

Dirk Shoemaker

Keyword(s):

American Association ◽

Chromatographic Determination ◽

Reversed Phase ◽

Fluorescence Detector ◽

Liquid Chromatographic Determination ◽

Optimum Wavelength ◽

The Mean ◽

Sensitivity Data ◽

Liquid Chromatographic

Abstract A reliable, improved liquid chromatographic (LC) method has been developed for the measurement of thiamine and riboflavin in foods. The major improvement in the method is the chromatographic separation achieved. The method is also very reproducible and extremely sensitive. After autoclave extraction, samples are derivatized to form thiochrome (a highly fluorescent oxidation product of thiamine). Riboflavin is naturally fluorescent. Interferences are removed on a Ci8 cartridge and chromatographed by using a reversed-phase separation. The mobile phase used is 72% 0.005M NH4OAc (pH 5.0)-28% MeOH. Fluorescence detection using wavelength switching, 370-435 for thiamine and 370-520 for riboflavin, allows determination of each vitamin at its optimum wavelength for maximum sensitivity. Detection limits were 0.05 ng for both thiamine and riboflavin. The method can also be performed by using a fluorescence detector at a single wavelength, but with a sacrifice of sensitivity. Data comparisons between AOAC fluorometric and LC results were excellent for routine samples, as well as for American Association of Cereal Chemists (AACC) check samples. All LC results from AACC samples were within 2 standard deviations of the mean. Reproducibility was 1.9% for thiamine and 1.6% for riboflavin.

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Comparison of Liquid Chromatographic Method to AOAC Microbiological Method for Determination of L-Tryptophan in Tablets and Capsules

Journal of AOAC International ◽

10.1093/jaoac/76.2.414 ◽

1993 ◽

Vol 76 (2) ◽

pp. 414-417 ◽

Cited By ~ 1

Author(s):

Henry S Kim ◽

Gerald Angyal

Keyword(s):

Reversed Phase ◽

Precolumn Derivatization ◽

Microbiological Method ◽

Test Portion ◽

Liquid Chromatographic Method ◽

Relative Standard ◽

Phase Liquid ◽

The Mean ◽

Liquid Chromatographic

Abstract A reversed-phase liquid chromatographic (LC) method coupled with precolumn derivatization of L-tryptophan with phenylisothiocyanate was compared to the AOAC microbiological method for determining L-tryptophan in tablets and capsules. For the microbiological method, the concentrations of L-tryptophan were 4-8% lower in autoclaved test samples (hot method) than in test samples that were not autoclaved (cold method). When L-tryptophan values obtained by the LC method were compared to those obtained by the cold microbiological method, no significant differences were observed (P > 0.05). The mean relative standard deviations were 2.9% for the LC method and 1.6% for the cold microbiological method. The mean recoveries of standard L-tryptophan added before analysis were 99% for the LC method and 101 % for the cold microbiological method. These results demonstrate that both methods are reliable for determining free L-tryptophan contained in tablets and capsules. However, the LC method has the advantages of using a smaller test portion and having a shorter analysis time.

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Determination of isotope fractionation of Cr(iii) during oxidation by LC/low-resolution MC-ICPMS

Journal of Analytical Atomic Spectrometry ◽

10.1039/c9ja00388f ◽

2020 ◽

Vol 35 (3) ◽

pp. 560-566

Author(s):

Jakub Karasiński ◽

Cuc Thi Nguyen-Marcińczyk ◽

Marcin Wojciechowski ◽

Ewa Bulska ◽

Ludwik Halicz

Keyword(s):

Inductively Coupled Plasma ◽

Isotope Fractionation ◽

Isotopic Analysis ◽

Reversed Phase ◽

Ion Pair ◽

Reversed Phase Chromatography ◽

Inductively Coupled ◽

Plasma Mass Spectrometry ◽

Sensitive Method

A robust and sensitive method for the precise isotopic analysis of 53Cr/50Cr during Cr(iii) oxidation by coupling ion pair reversed-phase chromatography and Multicollector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) is presented.

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