LC-MS/MS measurements were performed with a 1260 Infinity HPLC system (Agilent Technologies, Böblingen. Germany) and a QTrap 5500 mass spectrometer (AB Sciex, Darmstadt, Germany, TurbolonSpray interface). An Ascentis® Express C18-column (10 cm × 3.0 mm; 2.7 μm; Sigma-Aldrich) was used and Milli-Q water with 10 mM NH4Ac as solvent A and MeOH with 10 mM NH4Ac as solvent B. The following gradient was applied: 0 min, 95% solvent A; 3 min, 5% solvent A; 6.1 min, 95% solvent A. The flow rate was 300 μL/min and 5 μL were injected. The calibration was performed by diluting naled and dichlorvos with MeOH (LOD: dichlorvos 2 nmol/L, naled 0.3 nmol/L; corresponds to dichlorvos 7 × 10−2 pmol/embryo, naled 8 × 10−3 pmol/embryo). The transitions for naled (398–127, 382–128) and dichlorvos (221–109, 221–127) were acquired in multiple reaction monitoring. Reported data for the extracts were not corrected for matrix effects and recovery after sample preparation (matrix effects naled < 45%, recovery naled < 5%; matrix effects dichlorvos < 10%, recovery dichlorvos > 90%).
Ascentis express c18 column
Manufactured by Merck Group
Sourced in United States, Germany
The Ascentis Express C18 column is a high-performance liquid chromatography (HPLC) column designed for the separation and analysis of a wide range of compounds. It features a core-shell particle technology that provides efficient and rapid separations. The column's stationary phase is made of porous silica particles with a bonded C18 ligand, making it suitable for the analysis of a variety of organic compounds.
Automatically generated - may contain errors
Lab products found in correlation
Accela hplc system, by Thermo Fisher Scientific (4 mentions)
1260 infinity 2 system, by Agilent Technologies (3 mentions)
Surveyor hplc system, by Thermo Fisher Scientific (3 mentions)
Ltq orbitrap xl mass spectrometer, by Thermo Fisher Scientific (2 mentions)
Ltq orbitrap xl, by Thermo Fisher Scientific (2 mentions)
Openlab chemstation, by Agilent Technologies (2 mentions)
Api sciex 6500 triple quadrupole mass spectrometer, by AB Sciex (2 mentions)
30ad uplc system, by Shimadzu (2 mentions)
0.2 micron stainless steel guard column, by Waters Corporation (2 mentions)
C18 ascentis c18 supelguard guard column, by Merck Group (2 mentions)
1260 infinity hplc system, by Agilent Technologies (1 mentions)
Qtrap 5500 mass spectrometer, by AB Sciex (1 mentions)
Xevo tq s tandem quadrupole mass spectrometer, by Waters Corporation (1 mentions)
Millipore filter, by Merck Group (1 mentions)
Acquity uplc h class system, by Waters Corporation (1 mentions)
Silica gel 60 plate, by Merck Group (1 mentions)
Internal standards, by Avanti Polar Lipids (1 mentions)
Targetlynx software version 4, by Waters Corporation (1 mentions)
Xevo tq s uhplc ms ms, by Waters Corporation (1 mentions)
Acquity xevo tqs, by Waters Corporation (1 mentions)
62 protocols using ascentis express c18 column
1
LC-MS/MS Quantification of Naled and Dichlorvos
2
Chromatographic Analysis of Plant Extract
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
Chromatographic analyses were performed using a Waters Acquity UPLC H-Class system equipped with a diode array detector (DAD) and a Waters Xevo TQ-S tandem quadrupole mass spectrometer with a Z-spray source operating in negative ion mode. Stock solutions containing 1.0 mg/mL of the extract or the standard acteoside in LC-grade methanol were prepared separately with sonication over 30 min each and filtered through 0.45 μm Millipore filters (Merck Millipore). The solutions were diluted to 10 μg/mL with methanol, then, aliquots (5 μL) were injected onto a Sigma-Aldrich Ascentis Express C18 column (100 × 4.6 mm i.d.; 2.7 μm particle size). The mobile phase consisted of water containing 0.1% formic acid (solvent A) and methanol containing 0.1% formic acid (solvent B) supplied at a flow rate of 0.5 mL/ min according to the elution profile: isocratic with 3% B between 0 and 4 min, followed by linear gradients from 3 to 60% B between 4 and 19 min and from 60% to 90% B between 19 and 23 min, and finally returned to 3% B between 23 and 28 min. The eluent was monitored by DAD in the range of 210 to 720 nm and by MS with the optimized source and operating parameters as follows: capillary voltage 2.50 kV, Z-spray source temperature 150 °C, desolvation temperature (N2) 350 °C, desolvation gas ow 600 L/h, and mass range of m/z 150 to 600 in full-scan mode.
3
Quantification of 7α,25OHC in serum and tissues
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
7α,25OHC levels were analyzed using a validated HPLC-MS method37 (link). Briefly, serum samples or tissue homogenates were placed in glass vials containing deuterated internal standards and dichloromethane, methanol and water in the presence of butylated hydroxytoluene (10 µg) and ethylenediaminetetraacetic acid (20 ng) to prevent oxidation. Following extraction, the lipid fraction was purified by solid phase extraction to remove cholesterol. The oxysterol fraction was analyzed by HPLC-MS using an LTQ-Orbitrap XL mass spectrometer (Thermo Fisher) coupled to an Accela HPLC system (Thermo Fisher). Chromatographic separation was performed using an Ascentis Express C-18 column (2.7 µm, 150 × 4.6 mm, Sigma), kept at 15 °C. Mobile phase was a gradient of methanol and water containing acetic acid. Calibration curves were prepared in the same conditions.
4
Quantification of Quinic and Chlorogenic Acids in Plant Extracts
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
The presence of quinic and chlorogenic acids in ALE, ABE, and ARE was confirmed by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) using the chromatographic set up described in Section 4.2 , operated in the negative ion mode. Aliquots (5 µL) of extracts and reference standards (1 mg mL−1) were injected onto an Ascentis Express C18 column (100 × 4.6 mm i.d.; 2.7 µm; Sigma Aldrich) and gradient eluted with a mixture of formic acid (0.1%) in methanol (solvent A) and formic acid (0.1%) in water (solvent B) supplied at a flow rate of 0.5 mL min−1 according to the program: 3% A between 0 and 4 min, 3% to 60% A between 4 and 15 min, 60% to 90% A between 15 and 19 min, and finally 3% A between 19 and 24 min. The source was maintained at 150 °C, the capillary voltage was 2.5 kV, the desolvation temperature was 300 °C, the flow rate of desolvation gas (N2) was 600 L h−1, and the mass scan range was 100–700 m/z in the full scan mode. All analyses were carried out in triplicate.
5
Quantitative Bile Acid Profiling in Feces
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
Bile acids were analyzed using method validated method adapted from Guillemot-Legris et al.49 (link). Briefly, lyophilized feces (5 mg) were homogenized in ice-cold distilled water prior to protein precipitation using acetone containing seven deuterated bile acids used as internal standards. Samples were next centrifuged, and the supernatant was evaporated to dryness under nitrogen steam. The resulting residue was resuspended in methanol and injected in the HPLC–MS system consisting of an LTQ-Orbitrap XL mass spectrometer (Thermo Fisher Scientific) coupled to an Accela HPLC system (Thermo Fisher Scientific). Analyte separation was performed on an Ascentis Express C-18 column (2.7 µm, 100 × 4.6 mm) (Sigma-Aldrich) using a gradient between acetonitrile and water, both containing formic acid. Mass spectrometry analysis was performed using an electrospray ionization source in the negative mode. Calibration curves were prepared in the same conditions.
6
Isolation and Characterization of Rhamnolipids from P. aeruginosa
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
Two liters of P. aeruginosa PA14 were grown in LB medium at 37°C with constant shaking (250 rpm) for 16–18 h. Cell-free supernatant was extracted by liquid-liquid extraction with equal volume of EtOAc. The organic extracts were concentrated on a rotary evaporator and analyzed by thin layer chromatography (TLC) on silica gel 60 plates (Merck). The column (2.5 cm × 35 cm) was packed with silica gel in chloroform and not allowed to dry. The sample was applied on the surface of the column and eluted with chloroform/methanol (v/v = 50:1, 20:1 and 10:1). Each fraction was evaporated on a rotary evaporator and analyzed by HPLC-MS/MS by using Bruker amaZon X ion trap mass spectrometer (operating in autoMS(2) positive ESI mode, scanning m/z 100–1800) coupled with a Dionex UltiMate 3000 HPLC, with an Ascentis Express C18 column (150 mm 4.6 mm, 2.7 m, Sigma-Aldrich) and A (acetonitrile with 0.1% formic acid) and B (water with 0.1% formic acid) as the mobile phases at 1 ml min−1. The solvent gradient was 0–45 min, 5% -100%A. Rhamnolipids containing fractions were further purified by Sephadex LH-20 and eluted with MeOH. Pure rhamnolipids were characterized by 1D and 2D NMR as well as MS/MS analysis.
7
Lipidomic Analysis of Sphingolipids
8
Quantitative Bile Acid Analysis by HPLC-MS
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
Bile acid quantification was performed by HPLC-MS as previously described [41 (link)]. Briefly, liver samples were homogenized in ice-cold distilled water, and proteins were precipitated using acetone in the presence of deuterated internal standards. The samples were next centrifuged, the supernatant recovered and evaporated to dryness. The resulting residue was resuspended in methanol and analyzed by HPLC-MS using an LTQ-Orbitrap XL coupled to an Accela HPLC system (Thermo Fisher, Merelbeke, Belgium). Analyte separation was performed on an Ascentis Express C-18 column (2.7 µm, 4.6 × 100 mm) (Sigma-Aldrich, St. Louis, MI., USA). The separation was achieved using a gradient of H2O-ACN-formic acid 75:25:0.1 (v/v/v) and ACN-formic acid 100:0.1 (v/v). The MS analysis was performed in the negative mode with an ESI ionization source. Calibration curves were prepared using the same conditions. Data are expressed as pmol normalized by the amount of tissue. Values below the LOQ (for data sets with less than 25% of such missing values) were imputed using the function impute.QRILC in the R package imputeLCMD [42 (link)].
9
Quantification of Plasma Lipids and Oxylipids
10
Comprehensive Analysis of Reaction Products
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
The reactions were monitored by LC-DAD-MS, employing a liquid chromatograph coupled with a mass spectrometer Acquity Xevo TQS (Waters®), Ascentis® Express C18 column (10.0 cm × 3 mm, 2.7 μm) from Sigma-Aldrich. The setup included a DAD detector (200–700 nm) and both analysis modes, positive and negative, were employed to identify the reaction products.
For preparative High Performance Liquid Chromatography, a Shimadzu® HPLC system, equipped with CBM-20A controller, LC6AD bombs, SPD-20A detector, DGU-20A5 degas and Rheodyne manual injector, was used. Initially, a Shimadzu-ODS C18 column (250 × 4.6 mm, 5 μm) was used, followed by a Luna C18 column (250 × 20.00 mm, 5 μm) from Phenomenex®. The method was a linear gradient, mixture of methanol and water, both with 0.1% of formic acid, starting from the proportion 60 : 40 (MeOH/H2O) to 98 (MeOH/H2O) in 30 minutes. The flow rate was set at 1 mL min−1 for the analytic mode and 12 mL min−1 for preparative mode. The wavelength range used was 371–480 nm.
For preparative High Performance Liquid Chromatography, a Shimadzu® HPLC system, equipped with CBM-20A controller, LC6AD bombs, SPD-20A detector, DGU-20A5 degas and Rheodyne manual injector, was used. Initially, a Shimadzu-ODS C18 column (250 × 4.6 mm, 5 μm) was used, followed by a Luna C18 column (250 × 20.00 mm, 5 μm) from Phenomenex®. The method was a linear gradient, mixture of methanol and water, both with 0.1% of formic acid, starting from the proportion 60 : 40 (MeOH/H2O) to 98 (MeOH/H2O) in 30 minutes. The flow rate was set at 1 mL min−1 for the analytic mode and 12 mL min−1 for preparative mode. The wavelength range used was 371–480 nm.
About PubCompare
Our mission is to provide scientists with the largest repository of trustworthy protocols and intelligent analytical tools, thereby offering them extensive information to design robust protocols aimed at minimizing the risk of failures.
We believe that the most crucial aspect is to grant scientists access to a wide range of reliable sources and new useful tools that surpass human capabilities.
However, we trust in allowing scientists to determine how to construct their own protocols based on this information, as they are the experts in their field.
Ready to get started?
Sign up for free.
Registration takes 20 seconds.
Available from any computer
No download required
Revolutionizing how scientists
search and build protocols!