Catechins, theanine and caffeine were analyzed on a Waters High Performance Liquid Chromatography (HPLC) system equipped with Waters 600 controller and Waters 2489 UV Detector (280 nm). The Empower TM 3 software was used for instrument operation control and data collection. Chromatographic separation was performed on a Gemini 5u C18 110A column (250×4.60 mm, 5 μm, Phenomenex Inc., Torrance, CA), with a solvent system consisting of 0.17% (v/v) acetic acid (A) and 100% acetonitrile (B); a linear gradient at a flow rate of 1.0 mL/min was set as follows: B from 8 to 28% (v/v) in 30 min was initiated, followed by B from 28 to 100% (v/v) between 30 and 37 min, and B from 100 to 8% (v/v) between 37 and 46 min. Peaks were identified by comparison of retention times with those of standards49 (link). Total sugar content of tea infusion was determined by the anthrone-sulfuric acid method50 (link). Polysaccharides were isolated from tea infusion using an Amicon Ultra-0.5 Centrifugal Filter Device (UFS 503024, 3,000 Dalton cutoff).
2489 uv detector
Manufactured by Waters Corporation
Sourced in United States
The 2489 UV detector is a laboratory instrument designed to measure the ultraviolet (UV) absorbance of chemical samples. It provides accurate and reliable detection of UV-absorbing compounds in liquid chromatography (LC) and other analytical applications.
Automatically generated - may contain errors
Lab products found in correlation
E2695 hplc system, by Waters Corporation (4 mentions)
Astra 7, by Wyatt Technology (3 mentions)
2414 ri detector, by Waters Corporation (2 mentions)
Hplc system, by Waters Corporation (2 mentions)
Biosep sec s2000 column, by Phenomenex (2 mentions)
Superdex 30 increase column, by GE Healthcare (2 mentions)
Durapore 0.1 μm centrifuge filters, by Merck Group (2 mentions)
Dawn8 multiple angle light scattering detector, by Wyatt Technology (2 mentions)
600 controller, by Waters Corporation (1 mentions)
High performance liquid chromatography system, by Waters Corporation (1 mentions)
Gemini 5u c18 110a column, by Phenomenex (1 mentions)
E2695 separations module, by Waters Corporation (1 mentions)
500 mhz spectrometer, by Bruker (1 mentions)
717 plus autosampler, by Waters Corporation (1 mentions)
Symmetry shield rp18 column, by Waters Corporation (1 mentions)
515 hplc pump, by Waters Corporation (1 mentions)
7000 quadrupole ms ms, by Agilent Technologies (1 mentions)
Ctc combipal autosampler, by CTC Analytics (1 mentions)
E2695 separation module, by Waters Corporation (1 mentions)
Waters 600e, by Waters Corporation (1 mentions)
18 protocols using 2489 uv detector
1
HPLC Analysis of Tea Bioactive Compounds
2
Characterization of Poly(vinyl ether) Properties
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Proton nuclear magnetic resonance (1H-NMR) spectra of the poly(vinyl ether)s were recorded in CDCl3 as solvents at 25 °C on a Bruker-500 MHz spectrometer calibrated with tetramethylsilane as the internal standard (δH = 0.00). Molecular weights and MWD (Mw/Mn) of the poly(vinyl ether)s were obtained from a gel permeation chromatography (GPC) system with universal calibration using a Waters e2695 separations module, a Waters 2489 UV detector, a Waters 2414 RI detector, and four Waters styragel columns connected in the following order: 500, 103, 104, and 105. THF served as a solvent for the polymers with a concentration of 20 mg of polymer/10 mL of THF and mobile phase at a flow rate of 1.0 mL/min. ATR-FTIR spectra were recorded in situ by using a Mettler Toledo ReactIR 15 instrument with a DiComp probe coupled with an Material HgCdTe detector via AgX fiber. Sampling wavenumbers were from 4000 to 600 cm−1 at a resolution of 2 cm−1. The particle size in the emulsion was tested by a dynamic light scattering (DLS) analysis system using a Nanosight LM20. The reaction system temperature was detected with Testo 176T4, a data logger that records temperature per second.
3
HPLC Analysis of Organic Compounds
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The above preparations were analyzed using a Waters series high performance liquid chromatography (HPLC) system equipped with a Waters 2489 UV detector, 515 HPLC Pump and 717 plus Autosampler. Chromatographic separation was performed on a Waters Symmetry shield RP18 column (4.6 mm x 250 mm, 5 μm) at 30°C. The flow rate was set at 1 ml/min and the injection volume was 10 μl. The solvents, acetonitrile (A) and 0.4% aqueous formic acid (B), were applied at the following gradient: 0–15 min, 20% A-35% A; 15–20 min, 35% A- 55% A; 20–25 min, 55% A-60% A; 25 min, 60% A-70% A; 30–35 min, 70% A-20% A.
4
Gefitinib Release Kinetics from PEG-Fmoc-NLG2 Micelles
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The kinetics of gefitinib in vitro release from gefitinib/PEG5k-Fmoc-NLG2 was studied using a dialysis method. Briefly, 1 mL of gefitinib/PEG5k-Fmoc-NLG2 micelles containing 1 mg of gefitinib were placed in a clamped dialysis bag (MWCO 3.5 kDa) and immersed in 25 mL of phosphate-buffered saline (PBS) solution containing 0.5% (w/v) Tween. The experiment was performed in an incubation shaker at 37 °C at 100 rpm. At selected time intervals, both 10 μL of gefitinib/PEG5k-Fmoc-NLG2 micelle solution in the dialysis bag and 1 mL of medium outside the dialysis bag were withdrawn while the same amount of fresh medium was added for replenishment. For comparison, free gefitinib dissolved in 2% dimethyl sulfoxide (DMSO) was included as free diffusion control. The gefitinib released from micelles was also measured by Waters e2695 HPLC system equipped with a Waters 2489 UV detector (MA, USA). Then, 100 mM of ammonium acetate (pH =5) and acetonitrile (60:40, v/v) was used for the mobile phase. Gefitinib was detected at a 248 nm wavelength.
5
Quantification of Cellular Metabolites
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Extracellular concentrations of organic acids (acetate, lactate, formate) and ethanol were determined by HPLC (BioRad HPX-87H 300 * 7.8 mm column, at 59 °C, 0.6 mL/min, 1.5 mM phosphoric acid in Milli-Q water as eluent, coupled to a Waters 2414 RI detector and a Waters 2489 UV detector at 210 nm).
Processed extracellular and total broth samples were analysed by GC–MS/MS, GC–MS and LC–MS/MS. Metabolites of the central carbon pathways [glycolysis, pentose phosphate pathway (PPP), tricarboxylic cycle (TCA)] were quantified with GC–MS/MS (7890A GC coupled to a 7000 Quadrupole MS/MS, both from Agilent, Santa Clara, CA, equipped with a CTC Combi PAL autosampler, CTC Analytics AG, Zwingen, Switzerland), as described in [43 (link)] and/or anion-exchange LC–MS/MS [44 (link)]. GC–MS was used for the quantification of amino acids, as described in [45 (link)]. Ion-pair reversed phase LC–MS/MS was used for the quantification of nucleotides, as described in [46 (link)]. The isotope dilution mass spectrometry (IDMS) method, described in [42 (link), 47 (link)], was used for the metabolite quantification.
Processed extracellular and total broth samples were analysed by GC–MS/MS, GC–MS and LC–MS/MS. Metabolites of the central carbon pathways [glycolysis, pentose phosphate pathway (PPP), tricarboxylic cycle (TCA)] were quantified with GC–MS/MS (7890A GC coupled to a 7000 Quadrupole MS/MS, both from Agilent, Santa Clara, CA, equipped with a CTC Combi PAL autosampler, CTC Analytics AG, Zwingen, Switzerland), as described in [43 (link)] and/or anion-exchange LC–MS/MS [44 (link)]. GC–MS was used for the quantification of amino acids, as described in [45 (link)]. Ion-pair reversed phase LC–MS/MS was used for the quantification of nucleotides, as described in [46 (link)]. The isotope dilution mass spectrometry (IDMS) method, described in [42 (link), 47 (link)], was used for the metabolite quantification.
6
HPLC Analysis of Ibuprofen
7
HPLC Analysis of Organic Compounds
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The HPLC Waters Alliance apparatus comprised a Waters Alliance 2489 UV detector, a Waters Alliance e2695 separation module, and a Waters column heater (Waters, Milford, MA, United States). The chromatographic separations were performed on a 2.5 μm C8 Luna (150 mm × 4.6 mm i.d.) column (Phenomenex, Torrance, CA, United States) kept at 30°C, using a mobile phase consisting of acetonitrile: water at 60:40 (v/v) at a flow rate of 1.0 ml/min. UV detection at 247 nm was used.
8
Peptide Purification and Characterization
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Crude peptides were purified by RP-HPLC (Waters 600E) using a semi-preparative C18-μ Bondapak column at a flow rate of 5 mL/ min. Binary solvent system were used, solvent A (0.1% TFA in H2O) and solvent B (0.1% TFA in CH3CN). A Waters 2489 UV detector was used with dual detection at 214 and 254 nm. A total run time of 20 min was used and gradient used for purification was 5–100% CH3CN for 18 min followed by 100% CH3CN till 20 min. Purity of the peptides were confirmed using Waters 600E analytical HPLC system using Waters C8 analytical column at a flow rate of 1 ml/min, linear gradient of 5–100% CH3CN over 18 minutes in a total run time of 20 min. The purified peptides were characterized by mass spectrometry on Agilent-Q-TOF 6500 instrument, in ESI positive mode, equipped with Mass hunter work station software.
9
HPLC Fractionation of Tissue Extract
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The TE extract (500 μL) was fractionated on a Waters 2545 HPLC system and 2489 UV detector, an autosampler, and a Waters 2767 auto-fraction collector using a TSK-gel ODS C18 column (250 × 5 mm i.d., 5 μm) with the following program of gradient elution: 0 min, 5% B; 15 min, 40% B; 20 min, 80% B; 22 min, 100% B; 23 min, 5% B; 30 min, 5% B, in which mobile phase A is 0.1% formic acid (dissolved in ultra-pure water) and mobile phase B is acetonitrile, the flow rate was set to 3.0 mL/min, and the detection wavelength was 260 to 280 nm. A total of 20 fractions were collected, and equal fractions were pooled and dried in a vacuum concentrator for further analysis.
10
HPLC Quantification of Rifapentine and Linezolid
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Rifapentine and linezolid contents in the sample were determined by using HPLC. The HPLC system (Waters, Milford, MA, USA) includes the Waters e2695 system, Waters 2489 UV detector, and Empower Chromatography Data software package. Each test sample (20 μL) was injected into the Epic C18 (4.6×150 mm, 5 μm; ES industries Inc., West Berlin, NJ, USA) column. The flow rate of the mobile phase was 1 mL/min. The mobile phase for rifapentine was 45% KH2PO4 (0.0375 mol/L, pH 4) and 55% acetonitrile with the detection wavelength set at 335 nm. The mobile phase for linezolid was 25% KH2PO4 (0.0375 mol/L, pH 4) and 75% acetonitrile, and the detection wavelength used was 250 nm. The standard curves with concentrations ranging from 1 to 60 μg/mL (R2=0.9999) were drawn by measuring the contents of rifapentine and linezolid standards.
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