Determination of paracetamol (acetaminophen) in different body fluids and organ samples after solid-phase extraction using HPLC and an immunological method

Abstract

A solid-phase extraction method routinely used for serum samples was improved and applied to the qualitative and quantitative determination of paracetamol in different body fluids, e.g. blood, urine, cerebrospinal fluid, synovial fluid, vitreous humor, and in tissue samples. A very simple method showed best results: Body fluids were mixed with phenacetine as internal standard and phosphate buffer (pH 6.8). Then protein was precipitated using acetonitrile. After strong centrifugation the supematant was transferred to a preconditioned Bakerbond C18-SPE-column. Elution with methanol without a prior washing step showed best recovery rates. The extracts were investigated using high-performance liquid chromatography with ultraviolet detection, a photometrical and an immunochemical method.

A Highly Selective and Sensitive Spectrofluorimetric Method for the Determination of N-acetyl-4-aminophenol at Nano-trace Levels in Pharmaceuticals and Biological Fluids Using Cerium (IV)

“…The results of some pharmaceutical analyses are in excellent agreement with the reported (claimed) values. The results of pharmaceutical analyses by the spectrofluorimtric method were found to be in fantastic agreement with those obtained by British Pharmacopoeia Method [63]. The recovery percentages ranged from 90.4 ± 1.5 to 106.2 ± 2.2 % (Table 4).…”

Dexmedetomidine inhibits gastric emptying and oro-caecal transit in healthy volunteers

“…Venous blood samples were collected immediately before administration of paracetamol (baseline) and thereafter at 10, 20, 30, 40, 50, 60, 70, 80 min and 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.5, and 4 h. Plasma paracetamol concentrations were measured using reversed-phase high-performance liquid chromatography. 16 The lower limit of plasma paracetamol quantification was 0.1 mg litre 21 . Gastric emptying was assessed by the rate of paracetamol absorption using the time to peak plasma concentration, the peak plasma concentration, and the area under the plasma concentrationtime curve.…”

Influence on platelet aggregation of i.v. parecoxib and acetaminophen in healthy volunteers

“…Blood samples drawn after administration of the second drug were centrifuged at 3000 g for 10 min and plasma was stored at À20 C. Acetaminophen concentration was determined using high-performance liquid chromatography. 15 The limit of quantification was 0.1 mg litre À1 , and the day-to-day coefficients of variation were 4.2% at 2.5 mg litre À1 and 4.1% at 14.4 mg litre À1 (n=4).…”