Method of nuclear polarization measurement in a low-energy polarized target by means of the internal field

The experimental technique of a new type of polarization measurement especially for use with low-energy polarized targets is described. It is possible to derive the nuclear polarization as well as the nuclear spin-lattice relaxation time from measurements of the internal field.     

Voltammetric sensor based on magnetic particles modified composite electrode for determination of triamterene in biological sample

Some diuretic substances are controlled and monitored by the World Anti-Doping Agency as prohibited substances for use by athletes, such as triamterene (TRT). Thus, this work describes a voltammetric method based on graphite-epoxy composite electrode modified by tosyl-functionalized magnetic particles (GECE/MPs-To) for determination of TRT diuretic in urine sample. The TRT presented an oxidation peak at +1.24 V at GECE/MPs-To with irreversible behavior. Controlled potential electrolysis of the TRT at +1.26 V indicated the two electrons are transferred during amine group oxidation and the main product was identified by LC-MS/MS. The anodic peak current is 25 % higher at the modified electrode, suggesting that TRT is adsorbed on the magnetic particles. Using optimized conditions by using multivariate optimization of the parameters inherent of the square wave voltammetry, a calibration curve was constructed with a linear relationship for TRT from 0.500 to 99.8 μmol L^?1. The limits of detection and quantification were 1.47 and 4.91?×?10^?7 mol L^?1, respectively. The proposed method was applied to urine sample and validated by LC-MS/MS technique where the values found and compared between the two techniques showed no significant difference at 95 % confidence.