PubMed · 4756742
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
M D Smith, M A Genshaw, J Greyson. 1973. Miniature solid state potassium electrode for serum analysis.. https://doi.org/10.1021/ac60331a051
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
A diflunisal ion selective electrode of the PVC membrane type with an ion-exchanger consisting of the tetraheptylammonium-diflunisal ion pair is described. The sensor exhibits a rapid, near-Nernstian, selective response to diflunisal anion in the pH range 7-10, with a (batch) detection limit of 1 x 10(-5) M. The ion sensor was used as a flow detector in an automated flow-injection analyzer to develop routine methods for assays (concentration range 1-50 x 10(-4) M, (flow) detection limit 2.6 x 10(-5) M), content uniformity, and dissolution studies of diflunisal formulations. No serious interference from common ions and tablet excipients was found, and the drug can be directly determined in colored samples without separation steps. Fourty measurements can be performed automatically per hour with a precision of 0.5-1.8% relative standard deviation. The automated method for the dissolution test provides a complete dissolution profile by the end of the experiment. Using the constructed ion sensor, the intramolecular hydrogen bonding of the diflunisal anion was studied, thereby revealing a new application of ion sensor potentiometry.
Explore the source record for details and available documents.
Silicate glasses without paramagnetic components show 29Si relaxation times, T1, in the order of minutes. Because of these T1 values, unacceptably long instrument times are needed to obtain satisfactory' signal-to-noise ratios. Therefore, all samples were doped with MnO when microstructures of electrode glasses were investigated. Small amounts of paramagnetic ions in the glass reduce the relaxation time but do not affect the electrode properties. In any case when the distribution of manganese ions is homogeneous, the relaxation rates are proportional to the MnO content. The spin-lattice relaxation times of the different Qn species are similar within error limits. The best spectra were obtained using 0.1 mol% MnO.