Spd 10a uv detector

Brains were homogenized in 0.4 M perchloric acid (containing 0.1% sodium metabisulfite, 0.05% EDTA) using a disperser (Ultra-Turrax^®, IKA, Stauffen, Germany). For analysis of kynurenine and KYNA, an isocratic reversed-phase HPLC system was used, including a Shimadzu LC-10AD dual piston, high pressure liquid delivery pump (Shimadzu Corporation, Kyoto, Japan), and a ReproSil-Pur C18 column (4 × 150 mm, Dr. Maisch GmbH, Ammerbuch, Germany). A mobile phase of sodium acetate (50 mM, pH 6.2, adjusted with acetic acid) and 7% acetonitrile was pumped through the reversed-phase column at a flow rate of 0.5 ml/min, and 20 μl samples were manually injected using a Rheodyne 7725i injector (Rheodyne, Cotati, CA, USA). Zinc acetate (0.5 M, not pH adjusted) was delivered post column by a syringe pump (P-500, Pharmacia, Uppsala, Sweden) at a flow rate of 10 ml/h. Kynurenine was detected using a Shimadzu SPD-10A UV detector (Shimadzu Corporation), coupled before the delivery of zinc, at an absorption wavelength of 360 nm. KYNA was measured with a Jasco FP-2020 Plus fluorescence detector (Jasco Ltd, Hachioji City, Japan) and excitation and emission wavelengths of 344 nm and 398, respectively. The signals from the detectors were transferred to a computer for analysis utilizing Datalys Azur (Grenoble, France). The retention times of kynurenine and KYNA were about 4 min and 7 min, respectively.

The chemical stability of the NanoCluster powder was determined by chromatographic analysis. The HPLC-UV system consisted of a Shimadzu CBM-20A system controller, LC-10AT solvent delivery pump, SPD-10A UV detector, and SIL-10AxL autoinjector. Chromatograms were acquired and analyzed using Shimadzu Class vp 7.4 software. A Kromasil C8 column (100 x 4.6 mm) was used for budesonide separation, while a Hypersil C18 (100 x 4.6 mm) was used for danazol. The powders used an isocratic system with a mobile phase of 55/45 acetonitrile/water at a flow rate of 1.1 mL/min. Detection was performed at 244 nm for budesonide, and danazol was detected at 288 nm. Samples of NanoClusters and micronized stock powder were made at a concentration of 250 μg/mL in acetonitrile and 30 μL was injected. The spectra showed a characteristic budesonide peak with a retention time of 4.55 min and a degradant peak with a retention time of 2.72 min. Danazol had a retention time of 9.2 min and a degradation peak at 6.35 min. Percent degradation was determined using the peak area of the degradant relative to the total peak area^{37 (link),38 (link),39 (link)}.