Isocratic reversed-phase HPLC method to measure pyrimethamine extracted from plasma of infants treated for toxoplasmosis

Abstract An isocratic HPLC method for measuring pyrimethamine extracted from infant plasma is reported. The method is an improvement over previously published methods by requiring lower volumes of plasma (100 microL) and having increased sensitivity to pyrimethamine at 210 nm. The procedure, which entails a basic organic extraction and subsequent HPLC chromatography of the reconstituted extract, can detect 1.4 ng and quantify 4.0 ng of pyrimethamine per 40-microL injection, with two analyses per 100-microL sample. Analytical recovery of pyrimethamine added to plasma at 10, 50, and 125 ng/100 microL averaged 80%, 92%, and 101%, respectively (n = 20). Within- and between-day CVs were less than 7%. Studies of various plasma samples from adults and infants (n = 15) revealed no interference from other plasma peaks with the analyte of interest.

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Fatty acids in erythrocytes measured by isocratic HPLC

Clinical Chemistry ◽

10.1093/clinchem/40.9.1707 ◽

1994 ◽

Vol 40 (9) ◽

pp. 1707-1712 ◽

Cited By ~ 32

Author(s):

R Abushufa ◽

P Reed ◽

C Weinkove

Keyword(s):

Fatty Acids ◽

Mobile Phase ◽

Limit Of Detection ◽

Reversed Phase ◽

Hplc Method ◽

Butylated Hydroxytoluene ◽

Reversed Phase Hplc ◽

Sample Stability ◽

Isocratic Hplc ◽

The Mean

Abstract We developed an isocratic reversed-phase HPLC method to measure arachidonic, palmitoleic, linoleic, eicosatrienoic, oleic, palmitic, and stearic acids from hydrolyzed erythrocytes. Washed erythrocytes were heated in methanol:HCl and the fatty acids extracted into hexane:amyl alcohol. After derivatization with 4-bromomethyl-7-methoxycoumarin, samples diluted in mobile phase (acetonitrile:water, 85:15 by vol) were injected onto a 250 x 4.6 mm C18 column, and the eluted fatty acids were detected fluorometrically. For all analytes, the mean within-batch CV was 8.2% (5.5-10.8%), the mean limit of detection was 7.0 mumol/L, a linear response was maintained up to 400 mumol/L, and results agreed well with those by gas chromatography. The addition of antioxidant (butylated hydroxytoluene) was essential for sample stability. We discuss hydrolysis and extraction times, derivatization temperature, critical steps in chromatography, and concentration units.

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Determination of 5-hydroxymethyl-2-furaldehyde in royal jelly by a rapid reversed phase HPLC method

Analytical Methods ◽

10.1039/c3ay40634b ◽

2013 ◽

Vol 5 (19) ◽

pp. 5010 ◽

Cited By ~ 5

Author(s):

Marco Ciulu ◽

Roberta Farre ◽

Ignazio Floris ◽

Valeria M. Nurchi ◽

Angelo Panzanelli ◽

...

Keyword(s):

Royal Jelly ◽

Reversed Phase ◽

Hplc Method ◽

Reversed Phase Hplc

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Validation of a reversed-phase HPLC method for 1,10-phenanthroline-5,6-dione and analysis of its impurities by HPLC–MS

Journal of Pharmaceutical and Biomedical Analysis ◽

10.1016/s0731-7085(03)00261-9 ◽

2003 ◽

Vol 33 (2) ◽

pp. 219-230 ◽

Cited By ~ 10

Author(s):

Ghulam A Shabir ◽

Nigel J Forrow

Keyword(s):

Reversed Phase ◽

Hplc Method ◽

Reversed Phase Hplc

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Simultaneous Determination of Preservatives (Methyl Paraben and Propyl Paraben) in Sucralfate Suspension Using High Performance Liquid Chromatography

E-Journal of Chemistry ◽

10.1155/2011/360431 ◽

2011 ◽

Vol 8 (1) ◽

pp. 340-346 ◽

Cited By ~ 5

Author(s):

Rajesh M. Kashid ◽

Santosh G. Singh ◽

Shrawan Singh

Keyword(s):

High Performance Liquid Chromatography ◽

Simultaneous Determination ◽

Mobile Phase ◽

High Performance ◽

Reversed Phase ◽

Hplc Method ◽

Reversed Phase Hplc ◽

Methyl Paraben ◽

Propyl Paraben

A reversed phase HPLC method that allows the separation and simultaneous determination of the preservatives methyl paraben (M.P.) and propyl paraben (P.P.) is described. The separations were effected by using an initial mobile phase of water: acetonitrile (50:50) on Inertsil C18 to elute P.P. and M.P. The detector wavelength was set at 205 nm. Under these conditions, separation of the two components was achieved in less than 10 min. Analytical characteristics of the separation such as precision, specificity, linear range and reproducibility were evaluated. The developed method was applied for the determination of preservative M.P. and P.P. at concentration of 0.01 mg/mL and 0.1 mg/mL respectively. The method was successfully used for determining both compounds in sucralfate suspension.

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