Uv detector

High performance liquid chromatography (HPLC) was used for general profiling of the crude extract based on their adsorption and partition. Fingerprints of the MOE was conducted to separate components of the extracts. Methanol extract of the leaves was analyzed for HPLC fingerprints using Agilent 1100 HPLC apparatus equipped with UV detector (Agilent technologies Santa. Chara CA, United States). HPLC stationary phase used was a TSKgel C18 column (150 mm × 4.6 mm, diameter 3 µm) while the mobile phase was 0.1% phosphoric acid—methanol (95%:5%) with flow rate of 0.7 ml/min, injection volume 20 µl, and the runtime was set at 25 min. The emission wavelength of 300 nm was used.

The SE-HPLC-LS analysis was performed using an Agilent 1100 HPLC system with a TSK-GEL G3000SWxl, 5 μm particle size, 7.8 mm ID × 300 mm length column (Tosoh Biosep, 08541). The detectors used were a Wyatt HELEOS MALS detector, a Wyatt Optilab TrEX RI detector, and an Agilent UV detector with wavelength set at 280 nm. The SE-HPLC-LS runs were performed at room temperature with 100 mM sodium phosphate, 250 mM sodium chloride, pH 6.8 buffer used as the mobile phase, and the flow rate was 0.5 mL/min. Samples were injected neat into the SE-HPLC-LS system for a load of approximately 280 μg. For molar mass calculation, refractive index increment, dn/dc = 0.185 (mL/g), was used. Results were reported as the molar mass of monomer and high molecular weight (HMW) species using the Astra software (Wyatt Technologies Inc.).

The liposomes and free BVP were isolated by ultrafiltration. 4.0 mL preparation was accurately measured and placed in an ultrafiltration tube with cutoff molecular weight of 100 kDa and centrifuged at 3000 rpm for 20 min. The encapsulated BVP-LP remained on the surface of the filter membrane and free drug was collected into the bottom of the filter [40 (link)]. The separated bottom phases were transferred to 10 mL volumetric flask and diluted to the volume with methanol. After filtration by a 0.22 μm microporous filtration membrane, the samples and reference solution were qualified by HPLC (Agilent 1260 L, C18 column (Hypersil GOLD C18, 250 × 4.6 mm², 5 μm, Thermo, USA), UV detector (set at 335 nm, Agilent Technologies Inc., California, USA) and the mobile phase was methanol/0.1% phosphoric acid solution (40:60, v/v) with a flow rate of 1.0 mL/min. The EE of BVP-LP was determined by Equation (1).
$EE=\frac{The mass of total BVP-the mass of free BVP}{The mass of total BVP}\times 100\%$

HPLC analysis was conducted using the Nova-Pak C18 column (150 mm × 3.9 mm, 60 A, Waters Associates, Harrow, UK) at 25°C at a flow rate of 1 mL/min by using a gradient mobile phase (water : methanol in 600 : 400 ratio) as the initial condition of the chromatography. The sample injection volume used was 10 μL. The absorption signal of oleuropein was examined at 233 nm by using the UV detector (Agilent Technologies, DE, USA).

The DAP-SSF residues, before and after exposure to Rhodococcus, and after vacuum filtration as previously described above, were dried under vacuum at 40 °C overnight and then were acetylated with acetic anhydride/pyridine (1/1, v/v) at ambient temperature for 24 h in a sealed flask under an inert atmosphere. The concentration of the lignin in the solution was approximately 20 mg/mL. After 24 h, the solutions were diluted with ~ 20 mL of ethanol and stirred for an additional 30 min, after which the solvents were removed with a rotary evaporator, followed by drying in a vacuum oven at 40 °C. Prior to GPC analysis the acetylated pre- and post-Rhodococcus fermentation residue samples were dissolved in tetrahydrofuran (1.0 mg/mL), filtered through a 0.45 µm filter, and placed in a 2 mL auto-sampler vial. The molecular weight distributions of the acetylated lignin samples were then analyzed on an Agilent GPC SECurity 1200 system equipped with four Waters Styragel columns (HR1, HR2, HR4, HR6), an Agilent refractive index (RI) detector, and an Agilent UV detector (270 nm), using tetrahydrofuran (THF) as the mobile phase (1.0 mL/min), with an injection volume of 20 μL. A standard polystyrene sample was used for calibration. The number-average molecular weight (M_n) and weight-average molecular weight (M_w) were determined by GPC.