Waters 2998 photodiode array detector pda

Cys-GGGRDN(M⁰)-Z_HER2:342 was kindly gifted by the Jiangsu Institute of Nuclear Medicine, and its chemical purity was greater than 95%. The maleimide derivative 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA-MAL) was purchased from CheMatech (Dijon, France). ¹⁸F was generated from a cyclotron through the proton irradiation of ¹⁸O-enriched water (HM67, Sumitomo Heavy Industries). All other commercially obtained chemicals were of analytical grade and used without further purification. The Waters high-performance liquid chromatography (HPLC) system with the Waters 2998 photodiode array detector (PDA) and the preparative C18 HPLC column (5 μm, 250 × 19 mm, Waters 130Xbridge) was used to purify the precursor. Another Waters RP-HPLC system equipped with the Radiometric 610TR flow scintillation analyzer (Perkin Elmer), the Waters 2487 dual λ absorbance detector and the Luna C18 HPLC column (5 μm, 250 × 4.6 mm, Phenomenex) was used to analyze the radiolabeled compounds. The mobile phases A and B were 0.1% v/v trifluoroacetic acid in water and 0.1% v/v trifluoroacetic acid in acetonitrile, respectively.

Standard diosgenin (SD) was procured from Sigma Aldrich (USA). An aqueous extract of Helicteres isora, extracted diosgenin, and standard diosgenin were undertaken for thin layer chromatography on pre-coated silica gel plates with solvent combinations of N-hexane: ethyl acetate (7.5: 2.5). The plates were heated in an oven at 90 °C for three to 5 min to observe the spots after being sprayed with a solution of ethanol, sulfuric acid, glacial acetic acid, and anisaldehyde reagent (135:5:1:3.7) [28 (link)]. Waters High Performance Liquid Chromatography system equipped with Waters 1525 Binary HPLC Pump, Waters 2998 - Photodiode Array Detector (PDA) and Waters Autosampler was used for chromatographic determination of diosgenin on Waters C-18 column. Waters Breeze 2 Software system was used for analysis and data acquisition.
ED and SD were dissolved in acetonitrile and filtered via a 0.10 μm syringe filter before use. Samples were injected using a rheodyne injector fitted with a 20 μl fixed loop. The mobile phase reported by Deshpande and Bhalsing, (2014) was referred to wherein acetonitrile: water (90:10, v/v) was used as a solvent system with a flow rate of 0.7mL/min maintaining the ambient temperature [29 (link)]. The PDA detector was set at 273 nm to acquire the chromatogram.