Determination of 5-aminosalicylic acid in pharmaceutical formulations by square wave voltammetry at pencil graphite electrodes

An analytical method for the determination of the anti-inflammatory drug 5-aminosalicylic acid (5-ASA) in pharmaceutical formulations using square wave voltammetry at pencil graphite electrodes was developed. After the optimization of the experimental conditions, calibration curves were obtained in the linear concentration range from 9.78 × 10-7 to 7.25 × 10-5 mol L-1 resulting in a limit of detection of 2.12 ± 0.05 x 10-8 mol L-1. Statistical tests showed that the concentrations of 5-ASA in commercial tablets and enemas obtained with the proposed voltammetric method agreed with HPLC values at a 95% confidence level.

Determinação de 2,5-hexanodiona em urina empregando cromatografia líquida de alta eficiência, após derivatização com 2,4-dinitrofenil-hidrazina

A method for quantifying urinary 2,5-hexanedione was optimized and validated. Urine samples were hydrolyzed and derivatized with 2,4-dinitrophenylhydrazine. The analyte was separated in a high performance liquid chromatography system with a diode array detector, using a C18 column (150 x 4.6 mm, p.d. 5 µm) and a mobile phase composed of phosphate buffer pH 2.3:acetonitrile (40:60, v/v), at a flow rate of 1 mL/min. The chromatograms were monitored at 334 nm. Retention time was 7.3 minutes. Main validation parameters were: coefficient of determination: 0.9994, accuracy: 96 to 107%; intra-assay precision (RSD): 3.08 to 6.72%; inter-assay precision (RSD): 2.54 to 8.17% and limit of quantitation of 0.19 µg/mL.

Crystal structures of 5-chloro-2-methoxybenzoates of Mn(II), Co(II), Ni(II) and Zn(II)

The crystal and molecular structures of [bis(5-chloro-2-methoxybenzoate)tetraaquamanganese(II)], [pentaaqua(5-chloro-2-methoxybenzoato)cobalt(II)] (5-chloro-2-methoxybenzoate), [pentaaqua(5-chloro-2-methoxybenzoato)nickel(II)] (5-chloro-2-methoxybenzoate) and [aquabis(5-chloro-2-methoxybenzoate)zinc(II)] monohydrate were determined by a single-crystal X-ray analysis. Mn(H2O)4L2 (where L = C8H6ClO3) crystallizes in the monoclinic system, space group P21/c. [Co(H2O)5L]L and [Ni(H2O)5L]L both are isostructural, space group P212121. The crystals of [Zn(H2O)L2] H2O are monoclinic, space group Pc. Mn(II) ion is positioned at the crystallographic symmetry center. Mn(II) and Co(II) ions adopt the distorted octahedral coordination but Zn(II) tetrahedral one.The carboxylate groups in the complexes with M(II) cations function as monodentate, bidentate and/or free COO-groups. The ligands exist in the crystals as aquaanions. The complexes of 5-chloro-2-methoxybenzoates with Mn(II), Co(II) and Zn(II) form bilayer structure.

IX Porvoon-ajo 10.5.1934

kuv., 15 x 22 cm

Kansalliset propaganda maantie pyöräilykilpailut 5.5.32

14 x 21 cm

Suomen pyöräilymestaruuskilpailut Turussa heinäkuun 4-5 p:nä 1936

14 x 22 cm

Kansalliset rata- ja maantiepyöräkilpailut sunnuntaina 22.5.38 5:s Myllymäen-ajo

14 x 21 cm

Kansalliset rata- ja maantiepyöräilykilpailut Helatorstaina 21.5.1936 3:s Myllymäen-ajo

14 x 21 cm

Kansalliset ratapyöräilykilpailut ja kansainväliset kuudennet Myllymäen-ajot sunnuntaina 21.5.1939

14 x 21 cm

5:s Nokia kilpailu 200 km maantiepyöräilyssä 24.7.-38

14 x 21 cm

Kansalliset rata- ja maantiepyöräilykilpailut sunnuntaina 30.5.37 4:jäs Myllymäen-ajo

14 x 21 cm

Hyvinkää-kilpailu pyöräilyssä 5.6.32

14 x 21 cm

Kansallinen maantiepyöräily 21.5.36

15 x 22 cm

Kansalliset rata- ja maantiepyöräilykilpailut 23. ja 24.5.31

14 x 22 cm

Kansalliset pyöräilykilpailut Herralahden urheilukentällä 29.5.1938

12 x 17 cm