Uv 1600 pc series spectrophotometer

All solvents used were of reagent grade. SLS (Sigma-Aldrich, St. Louis, MO, USA, product of Spain,) and aspirin (Sigma-Aldrich, St. Louis, MO, USA, product of Spain) were used with no further purification. Melting points were measured in open tubes with a Stuart Scientific apparatus and were uncorrected. IR spectra in the region of 4000–370 cm⁻¹ were obtained using a Cary 670 FTIR spectrometer (Agilent Technologies Santa Clara, CA, USA). The ¹H-NMR spectra were recorded on a Bruker AC 400 MHz FT-NMR instrument in a DMSO-d₆ solution (Bruker GmbH & Co. 28359 Bremen, Germany). A UV-1600 PC series spectrophotometer of VWR international GmbH, Darmstadt, Germany, was used to obtain electronic absorption spectra.

Dimethylsulfoxide (DMSO, Riedel-de Haen, Seelze, Germany) was used without any further purification. Silver nitrate (AgNO₃,) was purchased from Degussa (Berlin, Germany). For lens preparation, 2-hydroxyethyl-methacrylate (pHEMA), ethylene-glycole-dimethacrylate (EGDMA, MERCK, Germany), diphenyl-(2,4,6-trimethylbenzoyl)-phosphine oxide (TPO 97%, Sigma-Aldrich, Steinheim, Germany) as well as sodium chloride (NaCl, MERCK) and hydrochloric acid (HCl 37%, MERCK) were used. Tryptone tryptophan medium, beef extract powder, peptone bacteriological and soy peptone were purchased from Biolife. Agar (Louis, MO, USA, product of Spain) and yeast extracts were purchased from Fluka Analytical (Switzerland). D(+)-glucose and di-potassium hydrogen phosphate trihydrate were purchased from Merck. Melting points were measured in open tubes with a Stuart Scientific apparatus and were uncorrected. A UV-1600 PC series spectrophotometer of VWR was used to obtain electronic absorption spectra. ATR-FT-IR spectra in the region of 4000–370 cm⁻¹ were obtained with a Cary 670 FTIR spectrometer (Agilent Technologies Inc., Santa Clara, CA, USA). XRF measurement was carried out with Rigaku NEX QC EDXRF analyzer, (Austin, TX, USA).

The UV-1600 PC series spectrophotometer by VWR (Radnor, PA, USA) was used to record electronic absorption spectra in the wavelength range from 190 to 1100 nm. The pathlength of the quartz cell was 1 cm. All the measurements were performed at 20 °C with an accuracy of ± 0.01 °C [20 (link)].
All infrared spectra in the 4000 to 370 cm⁻¹ spectral region were obtained from KBr discs at room temperature with an Alpha spectrometer by Bruker. The spectral resolution for all measurements was set at 2 cm^–1. The absorption of the KBr was applied as a blank to calibrate the spectrometer [21 (link)].