Quantification of 4-Methylaminoantipyrine, the Active Metabolite of Dipyrone, in Human Plasma

Abstract

The method was demonstrated to be, simple, sensitive and rapid. It can be easily adopted in laboratories with access to LC-MS or MS/MS and applied to sample analysis in clinical settings where a large number of samples are generated.

Fenton, Photo-Fenton, H2O2 Photolysis, and TiO2 Photocatalysis for Dipyrone Oxidation: Drug Removal, Mineralization, Biodegradability, and Degradation Mechanism

“…It was first separated on a reverse phase HPLC column using an isocratic mobile phase. Then the m / z ratio recorded in MS spectra was verified using 4-isopropylantipyrine ( m / z = 231.3) as an internal standard . The nitrogen atom instead of carbon in the pyrazolinone moiety is the most preferred site of OH • attack releasing aniline .…”

“…D 3 is found as a derivative in the biotransformation of DIPY in humans . The formation of D 4 was via an unstable intermediate with m / z = 220.03 because of the presence of a diketo group more susceptible toward oxidation in acidic medium . The cleavage of N–N bond in the hydrazine group led to formation of N -phenylacetamide (D 4 ) with m / z = 136.04 as well as an acetamide (Figure a).…”

“…Then the m/z ratio recorded in MS spectra was verified using 4-isopropylantipyrine (m/z = 231.3) as an internal standard. 23 The nitrogen atom instead of carbon in the pyrazolinone moiety is the most preferred site of OH • attack releasing aniline. 4 It was formed via hydroxylation of the aromatic ring by addition of OH • as in Figure 1.…”

4‐Methylamino antipyrine determination in human plasma by high‐performance liquid chromatography tandem mass spectrometry

“…Several HPLC methods for 4-methylamino antipyrine determination in biological fluids have been described (Aguiar et al, 2013;Agundez, Martinez, Martin, & Benitez, 1994;Aupanun, Laus, Poapolathep, Owen, & Vullo, 2016;Carretero, Vadillo, & Laserna, 1995;Domínguez-Ramírez et al, 2017;Katz, Granit, Drayer, & Levy, 1984;Ojha, Rathod, & Padh, 2009;Shep et al, 2012;Suarez-Kurtz, Ribeiro, Estrela, Vicente, & Struchiner, 2001). For all of the methods, the C 18 stationary phase is used for chromatographic separation of MAA with the other metabolites of metamizole and endogenous interferences from plasma and urine samples.…”

“…For all of the methods, the C 18 stationary phase is used for chromatographic separation of MAA with the other metabolites of metamizole and endogenous interferences from plasma and urine samples. Generally, a liquid-liquid extraction sample preparation technique into ethyl acetate or chloroform with sodium hydroxide additive is described (Agundez et al, 1994;Aupanun et al, 2016;Katz et al, 1984;Ojha et al, 2009;Shep et al, 2012). The large volume of extraction solvent (4-5 ml) requires a long time for evaporation, which is undesirable when a large number of samples need to be analyzed.…”