Optical rotation data were determined on a Rudolph Research AUTOPOL III automatic polarimeter. UV data were collected on a Hewlett-Packard 8452A diode array spectrophotometer. NMR data were collected on Bruker Avance 500 or 700 MHz instruments equipped with CryoProbe and Varian 500 MHz instruments. LCMS analyses were carried out on a Waters Alliance 2695 HPLC module, 996 photodiode array detector, and Micromass Quattro triple quadrupole mass spectrometer equipped with ESI under the positive mode. Accurate mass data were collected on an Agilent 6244 or 6538 QTOF MS coupled to an Agilent 1290 HPLC. Semipreparative HPLC was performed using a Waters 1525 binary pump system with a Waters 2998 photodiode array detector and with Phenomenex Luna 5 µm C18(2) columns (110 Å, 250 × 4.6 mm, 1 mL/min; 110 Å, 250 × 10 mm, 4 mL/min). Chiral HPLC analysis was performed on a Waters 1525 HPLC system using a Phenomenex Lux 5 µm Cellulose-3 column (250 × 4.6 mm, 1 mL/min). X-ray data were collected using a diffractometer with a Difractis CMOS area detector on a Rigaku goniometer and Cu Kα radiation (λ = 1.54178 Å). All solvents were of ACS grade or better.
8452a diode array spectrophotometer
Manufactured by Hewlett-Packard
Sourced in United States
The 8452A diode array spectrophotometer is a laboratory equipment designed for the measurement and analysis of ultraviolet and visible light absorption spectra. It features a diode array detector that allows for rapid, simultaneous detection of a wide range of wavelengths. The core function of this device is to provide accurate and reliable spectral data for various applications, such as chemical analysis, material characterization, and biological studies.
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Lab products found in correlation
1260 series hplc, by Agilent Technologies (2 mentions)
Fluoromax 3 spectrofluorometer, by Horiba (2 mentions)
Escalab 250xi, by Thermo Fisher Scientific (2 mentions)
6538 qtof ms, by Agilent Technologies (1 mentions)
Avance 500, by Bruker (1 mentions)
Usb2000 miniature spectrometer, by OceanOptics (1 mentions)
Rebel t3i camera, by Canon (1 mentions)
1290 hplc, by Agilent Technologies (1 mentions)
Lcms 2020 system, by Shimadzu (1 mentions)
Apex ccd area detector, by Bruker (1 mentions)
Autopol 3, by Rudolph Research Analytical (1 mentions)
6538 hresi qtof ms, by Agilent Technologies (1 mentions)
Kintex column, by Phenomenex (1 mentions)
Benzyl alcohol, by Merck Group (1 mentions)
Quanta master qm 1, by Horiba (1 mentions)
Tma dph, by Thermo Fisher Scientific (1 mentions)
5 μm mixed c columns, by Hewlett-Packard (1 mentions)
Poly ethylene glycol standards, by Polymer Laboratories (1 mentions)
600 mhz spectrometer, by Bruker (1 mentions)
Fluoromax 4 spectrofluorometer, by Horiba (1 mentions)
35 protocols using 8452a diode array spectrophotometer
1
Analytical Characterization of Organic Compounds
2
Quantifying Growth Hormone Nanoparticle Encapsulation
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The loading efficiency (LE%) was determined by centrifugation. The GH-loaded NPs were separated from the solution by ultracentrifugation (Beckman OptimaTM LE-80 K Ultracentrifuge, GMI, Ramsey, MN, USA) at 14,000 rpm for 40 min. The supernatants that had recovered from centrifugation were decanted. The amount of non-incorporated GH in the supernatant was determined at 288 nm using a Hewlett-Packard 8452 A Diode Array spectrophotometer (Walldorf, Germany). The samples were prepared and measured in triplicate. The LE (%) was calculated using the following equation:
3
In Vitro Drug Release Kinetics
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The study was performed using a water shaking bath (IKASH-B20, Staufen, Germany). The tests were performed at a rotation speed of 50 rpm and maintained at 37 ± 0.5 °C in 100 mL PBS (pH 7.2). Five milliliter samples of the prepared solutions were placed in dialysis membranes (MWCO 500–1000 Da). At certain intervals, aliquots (2 mL) were withdrawn for the analysis. After each sampling stage, the volume was restored with 2 mL of PBS. The amount of GH released was determined by UV spectroscopy (absorbance at 288 nm) using a Hewlett-Packard 8452 A Diode Array spectrophotometer. Each in vitro drug release experiment was performed in triplicate. The percentage of drug release was calculated using the data obtained from the study.
4
Optical Characterization of Functional Materials
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Absorption measurements were performed using a Hewlett-Packard 8452A Diode Array spectrophotometer, using a cuvette filled with pure solvent as the blank. For PL spectroscopy, we used the 405-nm ion line of a diode laser operated at an excitation power density of ~1250Wm-2 as the excitation source. The PL was collected by an optical fiber (numerical aperture ~0.22) and directed to an Ocean Optics USB 2000+ miniature spectrometer. The efficiency of the system was corrected with an Ocean Optics calibrated light source. Photographs of the PE layers were taken with a Canon Rebel T3i camera.
5
Spectrophotometric Determination of Polymeric Color
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Percent polymeric color (% PC) of extracts was determined using the spectrophotometric assay of Giusti and Wrolstad (2001) [33 (link)]. Sample extracts were diluted with water in order to have an absorbance reading between 0.5 and 1.0 at 512 nm when evaluated by an 8452A Diode Array Spectrophotometer (Hewlett Packard, Palo Alto, CA, USA). For analysis, 0.2 mL of 0.90 M potassium metabisulfite was added to 2.8 mL diluted sample (bisulfite bleached sample) and 0.2 mL of DI water was added to 2.8 mL diluted sample (non-bleached, control sample). After equilibrating for 15 min, but not more than 1 h, samples were evaluated at λ = 700 nm, 512 nm, and 420 nm. Color density was calculated using the control sample according to the following formula:
Polymeric color was determined using the bisulfite-bleached sample using the following formula:
Percent polymeric color was calculated using the formula:
Polymeric color was determined using the bisulfite-bleached sample using the following formula:
Percent polymeric color was calculated using the formula:
6
In Vitro Release Study of Fluconazole-CDs in Ophthalmic Gels
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The in vitro release of fluconazole–CDs from the in situ-gelled systems was studied using a membraneless model using an no. 2 USP automated dissolution testing apparatus consisting of a Prolabo Dissolutest fitted with a Hewlett Packard 8452A diode array spectrophotometer. Similar membraneless methods using a modified dissolution testing apparatus and high volumes of simulated tear fluid was implemented for another study in order to characterize in vitro drug release of ophthalmic gels [37 (link)–38 (link)]. These models were demonstrated as more useful than membrane models (i.e., using Franz cells) as they mimic the clearance effect and dilution of the tear in the eye surface.
Hydrogels (5 g) were placed in open, 4 cm diameter, glass containers which were placed in the bottom of a beaker filled with 400 mL of simulated tear fluid at 37 °C and 75 rpm. The in situ gel formation occurred during the sol–gel transition upon contact with the simulated tear fluid.
Hydrogels (5 g) were placed in open, 4 cm diameter, glass containers which were placed in the bottom of a beaker filled with 400 mL of simulated tear fluid at 37 °C and 75 rpm. The in situ gel formation occurred during the sol–gel transition upon contact with the simulated tear fluid.
7
Polymer Molecular Weight Characterization
8
Comprehensive Analytical Characterization
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UV data were collected on a Hewlett Packard 8452A diode array spectrophotometer. Optical rotation data were determined on a Rudolph Research Analytical Autopol III automatic polarimeter. UV–CD spectra were measured on an AVIV circular dichroism spectrometer model 202-01. NMR data were obtained on a Varian VNMR spectrometer (500 MHz). Accurate mass data were collected on an Agilent 6538 HRESI QTOF MS coupled with an Agilent 1290 HPLC. LC-MS analyses were performed on a Shimadzu LC-MS 2020 system (ESI quadrupole) coupled to a photodiode array detector. The samples were separated using a Phenomenex Kintex column (2.6 µm C18 column, 100 Å, 75×3.0 mm). The HPLC system utilized SCL-10A VP pumps and system controller with a Gemini 5 µm C18 column (110 Å, 250×21.2 mm, flow rates of 1 to 10 mL/min). X-ray data were collected using a diffractometer with a Bruker APEX ccd area detector and graphite-monochromated Mo Kα radiation (λ = 0.71073 Å). All solvents were HPLC grade or better.
9
Absorption and Emission Spectroscopy of Compounds
10
Membrane Fluidity of Brain Endothelial Cells
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Brain endothelial cells from wild type and ApoB-100 transgenic mice were treated overnight with 10 µg/ml LDL or 10 µg/ml oxLDL. Control cells received culture medium. After treatment, cells were collected by trypsinization, washed once with PBS, resuspended in Ringer-Hepes buffer and counted. The density of the cells for the membrane fluidity tests was optimized by absorbance measurement to OD360 = 0.05 (Hewlett Packard 8452A Diode Array Spectrophotometer). Cells were labeled with 0.2 μM TMA-DPH (1-(4 trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene; Life Technologies, USA). Fluorescence anisotropy was measured on a T-format fluorescence spectrometer (Quanta Master QM-1, Photon Technology International, USA). Excitation and emission wavelengths were 360 and 430 nm (6 nm slits). Cells were kept under a continuous stirring at 37°C [25 (link), 26 (link)]. Anisotropy data were acquired in every second for 10 min. After measuring baseline anisotropy, we introduced a strong membrane fluidizer, benzyl alcohol (30 mM, Merck, Germany) as a positive control. Transgenic and wild type data were calculated and plotted as treatment vs. fluorescent anisotropy.
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