Analysis of Oligosaccharides Derived from Heparin by Ion-Pair Reversed-Phase Chromatography/Mass Spectrometry

2009 ◽  
Vol 81 (9) ◽  
pp. 3485-3499 ◽  
Author(s):  
Catalin E. Doneanu ◽  
Weibin Chen ◽  
John C. Gebler
Keyword(s):  
Mass Spectrometry ◽  
Reversed Phase ◽  
Ion Pair ◽  
Reversed Phase Chromatography ◽  
Chromatography Mass Spectrometry

Depletion of Residues from Milk and Blood of Cows Dosed Orally and Intravenously with Sulfamethazine

1994 ◽  
Vol 77 (4) ◽  
pp. 895-900
Author(s):  
Gaylord D Paulson ◽  
Vernon J Feil ◽  
Richard G Zaylskie ◽  
John M Giddings ◽  
William D Slanger
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Body Weight ◽  
Reversed Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Reversed Phase Chromatography ◽  
Mass Spectral ◽  
Chromatography Mass Spectrometry ◽  
Methyl Derivatives ◽  
Hydrolysis Of

Abstract Cows were dosed orally (n=4) or intravenously (n = 4) with sulfamethazine [sulmet; 4-amino-N(4,6-dimethyl-2-pyrimidinyl)benzenesutfonamide] for 5 consecutive days (220 mg/kg of body weight on day 1 and 110 mg/kg on days 2–5). The concentrations of sulmet, N4-acetylsulfamethazine (Ac-sulmet), and the N4-lactose conjugate of sulfamethazine (lac-sulmet) were measured in milk and blood collected at 24 h intervals after the last doses of sulmet were given. The method of analysis included (1) spiking of samples with known amounts of 13C6-labeled reference compounds, (2) resolution of the 3 compounds by reversed- phase chromatography, (3) hydrolysis of lac-sulmet, (4) treatment with diazomethane to yield N1-methyl derivatives, and (5) gas chromatography/mass spectrometry. The ratios of intensities of selected mass spectral ions containing 12C6 and the corresponding ions containing 13C6 were used for residue quantitation. Sulmet, which was always the most abundant residue in the blood, decreased to less than 100 ppb 4 days after the last doses were given and to less than 10 ppb 7 days after the last doses. The concentrations of sulmet in milk were approximately one fifth the concentrations of sulmet in blood. The concentrations of lac-sulmet and Ac-sulmet in milk were lower than the concentrations of sulmet in milk.

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