U 2800 uv vis spectrophotometer

In drug-loading procedure, 5 mg of 5FU and 5 mg of CUR were dissolved in 5 mL of DMSO and were added dropwise to 50 mg aqueous dispersion of C-MNP-HSA-FA. The mixture was allowed to stir for 6 h at room temperature. 5FU and CUR-loaded C-MNP-HSA-FA (5FU-CUR-C-MNP-HSA-FA) was separated by centrifugation.
The drug loading (DL) and entrapment efficiency (EE) of 5FU and CUR in C-MNP-HSA-FA were determined using the following equations: $$\text{DL}(\%)=\frac{\text{Weight of drug in nanoparticles}}{\text{Weight of nanoparticle}}\times 100,$$
$$\text{EE}\left(\%\right)=\frac{\text{Weight of drug in nanoparticles}}{\text{Weight of drug loaded}}\times 100.$$
The drug release was performed by suspending 10 mg of 5FU-CUR-MNP-HSA-FA NPs in 50 mL of phosphate buffer solution (pH 7.4) with 0.05% (w/v) of Tween^®80 at 37 °C. At specific time intervals, 1 mL of release buffer was aspirated and replaced by fresh phosphate buffer solution. The concentration of 5FU and CUR was determined using a Hitachi U-2800 UV–Vis spectrophotometer at a wavelength of 241 nm and 421 nm, respectively.

All decolorization experiments were performed in 250 mL Erlenmeyer flasks containing 100 mL of pre-enriched microbial consortium. Initially, 50 mg∙L⁻¹ of Trypan Blue dye was added into the pre-enriched culture flaks and kept under microaerophilic and aerobic (shaking at 120 rpm) incubation conditions at 30 °C ± 0.2 °C. Aliquots of 2 mL were withdrawn from the experimental and control media at regular intervals of 8 h till 24 h and the cell mass was harvested by adding an equal volume of ethyl acetate followed by centrifugation (7500 × g for 20 min, 4 ± 0.2 °C) to obtain a clear supernatant. Decolorization of the dye Trypan Blue was measured spectrophotometrically at a λ_max of 660 nm (U-2800 UV-vis spectrophotometer, Hitachi, Tokyo, Japan). Pre-enriched microbial consortium culture without dye was considered as the biotic control and tested under the same conditions. Uninoculated medium containing 50 mg∙L⁻¹ of dye served as the abiotic control. Unless otherwise specified, all the experiments were performed in three sets. The percent decolorization was calculated using the formula:
$\text{Decolorization }(\%)=\frac{{\text{Initial absorbance}}_{(\text{0 h})}-{\text{ Observed absorbance after incubation}}_{(\text{t})}}{{\text{Initial absorbance}}_{(\text{0 h})}}\times 100$

Immediately after opening the vial with DHA, an aliquot was taken out and used immediately for measurement of optical absorption spectra without the addition of any solvents. Another aliquot was weighted and solubilised in acetonitrile:methanol (1:1) at a concentration of 100 mg/mL and absorption spectrum was also measured. The remaining DHA was aliquoted into Eppendorf tubes (about 100 mg/tube), weighted, and exposed to the air at 37 °C to enable autooxidation. DHA depletion and formation of oxidation products were monitored by measurements of optical absorption using U-2800 UV–VIS spectrophotometer (Hitachi) after selected times since opening the DHA vial and solubilisation of DHA/oxidised DHA in acetonitrile:methanol (1:1).
To solubilise lipids from 16:0;22:6PC liposomes, the liposomes were extracted in chloroform/methanol mixture [15 (link)], followed by collecting the chloroform-enriched fraction, taking an aliquot for absorption measurements, and drying the rest under a stream of argon so to be resolubilised in acetone, benzene, or DMSO. All procedures were performed under dim red light.
The hydration of oxidised Di22:6PC lipid film resulted in its good solubilisation, and hence the absorption spectra were measured in PBS.