Lambda 25 uv vis spectrometer

Copper(II) chloride dihydrate; 3,4-difluorophenylacetic acid; 2-methylpyridine; 3-methylpyridine; 2,2-diphenyl-1-picrylhydrazyl radical (DPPH); ascorbic acid; iron(II) sulfate; hydrogen peroxide; nitric acid; sodium salt of the salmon sperm DNA (SS-DNA); methanol; and DMSO were purchased from Sigma-Aldrich, St. Louis, MO, USA. These chemicals were used without any further treatment. Distilled water was used for the experimental work. The melting points of the synthesized complexes were recorded in a capillary tube using a digital electro-thermal melting point apparatus. Elemental analysis was performed on a Leco CHNS 932. A Perkin Elmer atomic absorption spectrometer A analyst 700 was used to determine the percentage of copper. The electronic absorption spectra (200–800 nm) of the complexes were recorded using a Perkin Elmer UV/Vis spectrometer Lambda 25 in DMSO solvent. A nicolet-6700 FT-IR spectrophotometer (Thermo Scientific, Waltham, MA, USA) was used to record FT-IR spectra in the range of 4000–400 cm⁻¹, adopting the attenuated total reflectance (ATR) technique.

Pure water flux of the hollow fiber membrane was evaluated at a constant temperature of 25 °C using crossflow filtration system in three modules each containing five fibers with one end sealed. Prior to the test, the hollow fiber membranes were soaked in tap water for 30 min and followed by a pre-compression at 1 bar pressure for another 30 min to attain stable pure water volume flux. The pure water flux, J_w was determined using Equation (1) [43 (link)]:
where J_w signifies the permeation flux in L/m²·h. Q represents the amount of permeated pure water in L. A corresponds to the effective area of the membrane in m² and t is the time required to get the amount of Q in hour. The pure water permeability (PWP) was calculated by using Equation (2) [14 (link)]. TMP is the transmembrane pressure in bar.

The membrane oil rejection percentage (R) was determined based on Equation (3) [44 (link)]. The oil concentrations in the permeate and feed were determined using PerkinElmer UV-Vis Spectrometer Lambda 25 (Waltham, MA, USA) at the maximum absorbance of oily wastewater measured at 223 nm. C_P and C_F signify the permeate and the feed concentration in ppm, respectively.

The in vitro deposition of micronized naringin was evaluated using a glass impinger at a single stage (SSGI, European Pharmacopoeia 6.0 instrument, Copley Ltd. Scientific, Mothingam, UK).
A water/ethanol 9/1 v/v mixture was introduced in the upper (7 mL) and lower (30 mL) stages of the SSGI. Hard gelatin capsules (size 2) were filled with 20.0 ± 0.5 mg of naringin powders and introduced into the Turbospin. The vacuum pump was operated at a flow rate of 60 L/min for 5 s. Each deposition experiment was carried out on 10 capsules and repeated in triplicate. A UV spectrometer (UV/Vis spectrometer Lambda 25, Perkin-Elmer instruments, Waltham, MA, USA) was used at a wavelength of 283 nm to quantify the naringin deposited into the upper and the lower stages of the impinger. The analytic method was validated using standard solutions of naringin in the range of 70–400 mg/L. The emitted dose (ED) was gravimetrically determined and expressed as the percentage of the powder at the exit of the apparatus vs. the amount of powder introduced into the capsule. The ratio between the naringin recovered from the SSGI and the naringin emitted from the device was the recovered dose. The fine particle fraction (FPF) was defined as the percentage of the ratio of the naringin recovered from the lower stage of SSGI vs. the total loaded dose.

¹H NMR was recorded on a 400 MHz Bruker spectrometer running and analysed using TopSpin software. Deuterated acetone was employed as the reference. UV–Vis was performed on a PerkinElmer UV/VIS Spectrometer Lambda 25. XRD patterns were measured on a PANalytical X'Pert Pro MRD diffractometer using Ni filtered Cu K_α radiation at 40 kV and 40 mA. SEM-EDX measurements were carried out on a JEOL 6400 scanning electron microscope operated at 20 kV. IGA measurements were conducted on a Mettler Toledo TGA spectrometer. For ToF-SIMS samples were fabricated onto clean glass substrates. The samples were then soaked under dry flux in the dark for an hour before the ToF-SIMS measurements were recorded. Data were obtained using an IONTOF ToF.SIMS-Qtac LEIS spectrometer employing an Argon sputter gun for oxygen ion detection.

For UV VIS spectroscopy, recombinant V. carteri MCP was adjusted to 600 µM in purification buffer (100 mM Tris-HCl pH 8.0, 150 mM NaCl, 1 mM EDTA, 5% (v/v) glycerol). Spectra were recorded using a PerkinElmer UV/VIS Spectrometer Lambda 25 between 380 and 620 nm.

A red wine, from Ribera del Duero region and made from Cabernet Sauvignon grapes of the 2017 harvest, was used. The initial wine presented pH 3.89, alcoholic degree 15% (v/v), 5.1 total acidity (g/L tartaric acid), 0.48 volatile acidity (g/L acetic acid), 29 mg/L of free SO₂ and 74 mg/L of total SO₂, 15.1 colour intensity, % Abs 420 of 38.4, % Abs 520 of 50.1, % Abs 620 of 12.1 and a total polyphenol index of 66 according to OIV, 2003 [33 ]. The colour analysis was measured with UV/Vis Spectrometer Lambda 25 (Perkin Elmer, Singapore). Each measurement was made in duplicate according to Glories [34 (link)].
The wine was barrelled (March of 2018) in 10 barrels (225 L)—4 barrels with High wood-OTR, 4 barrels with Low wood-OTR and 2 control barrels constructed without traceability on the staves, used as control—to age the red wine. The barrels were maintained at 17 °C and with a relative humidity of 70% similar to the common cellar conditions. Wine samples were taken after 6 and 12 months of ageing, after which samples were stored at 18 °C until analysis and the barrels were filled after each sampling. Each sample from each barrel was analyzed in duplicate.

The formation of Sym. Radix/AgNPs 1 was checked using a Lambda 25 UV-vis spectrometer (PerkinElmer, Waltham, MA, USA). The analysis was performed in a wavelength range of 200 to 800 nm. Ultrapure water was used as the blank for the UV-Vis experiments.