The average molecular masses and the mass distributions of the obtained polylactide samples were determined by GPC in THF as the mobile phase at a flow rate of 1 mL min−1. The utilized GPCmax VE‐2001 from Viscotek was a combination of an HPLC pump, two Malvern Viscotek T columns (porous styrene divinylbenzene co‐polymer) with a maximum pore size of 500 and 5000 Å, a refractive index detector (VE‐3580), and a viscometer (Viscotek 270 Dual Detector). Universal calibration was applied to evaluate the chromatographic results.
MALDI‐ToF Mass Spectrometry : The end group analysis was performed by MALDI‐ToF on a Bruker ultrafleXtreme equipped with a 337 nm smartbeam laser in the reflective mode. THF solutions of trans‐2‐[3‐(4‐tert‐butylphenyl)‐2‐methyl‐2‐propenylidene]malononitrile (DCTB) (5 μL of a 20 mg/mL solution), sodium trifluoroacetate (0.1 μL of a 10 mg/mL solution), and analyte (5 μL of a 10 mg/mL) were mixed and a droplet thereof applied on the sample target. Protein 1 calibration standard is the name of the protein mixture used for calibration. For spectra 4000 laser shots with 24 % laser power were collected. The laser repetition rate was 1000 Hz. The homopolymer analysis was performed using Polymerix software (Sierra analytics).
Ve 3580
Manufactured by Malvern Panalytical
Sourced in United Kingdom
The VE 3580 is a laser diffraction instrument designed for particle size analysis. It measures the size distribution of particles suspended in a liquid medium or dry powders. The instrument uses the principle of laser diffraction to determine the particle size distribution, providing detailed information about the particle characteristics.
Automatically generated - may contain errors
Lab products found in correlation
Gpc max ve 2001, by Malvern Panalytical (2 mentions)
Gpcmax, by Malvern Panalytical (2 mentions)
Ultraflextreme, by Bruker (1 mentions)
Nanozs, by ZenBio (1 mentions)
270 dual detector, by Malvern Panalytical (1 mentions)
Gpc system, by Malvern Panalytical (1 mentions)
Gpc max system, by Malvern Panalytical (1 mentions)
Cary series uv vis spectrophotometer, by Agilent Technologies (1 mentions)
8 protocols using ve 3580
1
Polylactide Characterization by GPC and MALDI-ToF
2
Characterization of Nanogel Properties
3
Molecular Weight Characterization of HA Derivatives
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Weight and number average molecular weights (Mw and Mn) of proxHA and oxHA were determined by using a GPC system from Malvern (Herrenberg, Germany). The system consisted of a Viscotek GPCmax (in-line degasser, 2-piston pump and autosampler), a column oven (35 °C) refractive index (RI) detector (Viscotek VE3580), multiple angle light scattering detector (Viscotek SEC-MALS 20, laser wavelength 660 nm), and two Viscotek A-columns (A6000M, length = 300 mm, width = 8 mm, porous poly(methyl methacrylate), particle size 13 µm). An aqueous solution of Millipore H2O with 8.5 g/L NaNO3 and 0.2 g/L NaN3 was used as eluent and solvent for the polymers. The samples were dissolved with a concentration of 0.5 mg/mL overnight at RT and filtered with a 0.45 µm regenerated cellulose membrane. The measurements were performed with 100 µL injection volume with an elution rate of 0.7 mL/min. The molecular weights of the HA derivatives were calculated using a MALS calibration performed with a narrowly distributed PEG standard of Mw = 45,000.
4
Characterization of Polymers by SEC
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Size exclusion chromatography (SEC) was performed at room temperature using a Viscotek GPC max system equipped with a Viscotek guard column (10 × 4.6 mm) and two Viscotek columns LT 5000-L mixed medium (300 × 7.8 mm) fitted with a Viscotek VE 3580 refractometric detector and a Viscotek VE 3210 UV/Vis detector. THF was used as solvent with a flow rate of 1 mL·min−1. All molecular weights (Mn) and molecular weight distributions (dispersity, Mw/Mn, D) were determined by calibration to known, standard poly(methyl methacrylate) samples purchased from Polymer Laboratories (Church Stretton, United Kingdom).
5
Polymer Molecular Weight Determination
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The molecular weight of polymer 4 was determined using a Viscotek GPCmax with a Viscotek aqueous
A6000M (300 × 8.0 mm) column and an Aguard guard column. A Malvern
270 dual detector and a Viscotek VE 3580 RI detector were used to
detect reflective index (RI), viscosity (IV), and low angle light
(LAL) and right angle light (RAL) scattering signals. The dextran
standards with Mw 1270, 5220, 11 600,
25 000, and 68 082 g/mol were purchased from Sigma-Aldrich.
All the standards and polymer4 were dissolved in 0.3
M NaCl solution, and 0.3 M NaCl solution was also used as the eluent
at 0.5 mL/min. The retention volume was selected using the RAL peaks,
although other signals generate the same result.
The molecular
weight of polymer1′ , 2′ , 3′ and 5′ was determined using
the same GPCmax and detectors but with Guard-0478 and Malvern CLM1012
(I-MBMMW-3078) columns. The polystyrene (PS) standards with Mw 5200, 30 000, 200 000, 400 000,
and 900 000 were purchased from Alfa Aesar. The PS standards
and polymer1′ , 2′ , 3′ and 5′ were dissolved in a mixture
solvent of 20% methanol in THF. The same mixed solvent was used as
the eluent at 0.5 mL/min for the PS standards and the polymer samples.
A6000M (300 × 8.0 mm) column and an Aguard guard column. A Malvern
270 dual detector and a Viscotek VE 3580 RI detector were used to
detect reflective index (RI), viscosity (IV), and low angle light
(LAL) and right angle light (RAL) scattering signals. The dextran
standards with Mw 1270, 5220, 11 600,
25 000, and 68 082 g/mol were purchased from Sigma-Aldrich.
All the standards and polymer
M NaCl solution, and 0.3 M NaCl solution was also used as the eluent
at 0.5 mL/min. The retention volume was selected using the RAL peaks,
although other signals generate the same result.
The molecular
weight of polymer
the same GPCmax and detectors but with Guard-0478 and Malvern CLM1012
(I-MBMMW-3078) columns. The polystyrene (PS) standards with Mw 5200, 30 000, 200 000, 400 000,
and 900 000 were purchased from Alfa Aesar. The PS standards
and polymer
solvent of 20% methanol in THF. The same mixed solvent was used as
the eluent at 0.5 mL/min for the PS standards and the polymer samples.
6
PU Polymer Molecular Weight Analysis
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The molecular weights of the PU-DMPA and the PU-BDO were determined by a gel permeation chromatography and light-scattering (GPC–LS) system (Viscotek, United Kingdom) equipped with two Shodex HFIP columns and three detectors including RI (VE3580, Viscotek), right angle light scattering, and viscometer (Dual 270, Viscotek). HFIP at a flow rate of 1.0 mL/min was used as the eluent.
7
SEC-based Polymer Characterization and LCST Determination
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Size exclusion chromatography (SEC) was conducted with DMF as the mobile phase containing 5 mM NH 4 BF 4 additive at 70 1C at a flow rate of 1.00 mL min À1 . The SEC system was equipped with a solvent pump (Viscotek VE 1121), a degasser (Viscotek VE 7510), two Styragel columns (MGHHR-M E0057 and MGHHR-M E0058) and a refractive index detector (Viscotek VE 3580). DMF was used as the mobile phase at a flow rate of 1 mL min À1 . The apparatus was calibrated prior to analysis by using linear poly(methyl methacrylate) polymers with narrow molecular weight distributions as standards. Then, 100 mL of polymer aliquots in DMF (40 mg mL À1 ) was injected to the instrument to determine the average molecular weight (M n ) and index of polydispersity (Ð M ).
Determination of the polymers' lower critical solution temperature (LCST)
The polymers (5 mg) were dissolved in 1 mL of phosphatebuffered saline (PBS) pH 7.4 and gradually heated by immersing the solution in water bath of predetermined temperature and the LCST value was determined as the onset of optical turbidity for each sample by a Agilent Cary series UV-vis spectrophotometer at 550 nm.
Determination of the polymers' lower critical solution temperature (LCST)
The polymers (5 mg) were dissolved in 1 mL of phosphatebuffered saline (PBS) pH 7.4 and gradually heated by immersing the solution in water bath of predetermined temperature and the LCST value was determined as the onset of optical turbidity for each sample by a Agilent Cary series UV-vis spectrophotometer at 550 nm.
8
Molecular Weight Analysis of Polylactides
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The average molecular masses and the mass distributions of the obtained polylactide samples were determined by GPC in THF as the mobile phase at a flow rate of 1 mL min -1 . The utilised GPCmax VE-2001 from Viscotek was a combination of an HPLC pump, two Malvern Viscothek T columns (porous styrene divinylbenzene copolymer) with a maximum pore size of 500 and 5000 Å, a refractive index detector (VE-3580), and a viscometer (Viscotek 270 Dual Detector). Universal calibration was applied to evaluate the chromatographic results.
Some GPC samples were carried out at 1 ml min -1 at 35 °C with a THF eluent using a PLgel 5 μm MIXED-D 300 × 7.5 mm column using a GPC from Agilent. The system was referenced against 11 narrow molecular weight standards polystyrene standards with detection via refractive index response. A correction factor of 0.58 was applied to measured values.
Some GPC samples were carried out at 1 ml min -1 at 35 °C with a THF eluent using a PLgel 5 μm MIXED-D 300 × 7.5 mm column using a GPC from Agilent. The system was referenced against 11 narrow molecular weight standards polystyrene standards with detection via refractive index response. A correction factor of 0.58 was applied to measured values.
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