Apr 06, 2023

Public workspaceLignin Reductive Catalytic Fractionation (RCF) Monomers Analysis by Gas Chromatography Flame Ionization Detection (GC-FID)

  • 1Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory
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Protocol CitationHannah M. Alt, David G. Brandner, Gregg T. Beckham, Kelsey J. Ramirez 2023. Lignin Reductive Catalytic Fractionation (RCF) Monomers Analysis by Gas Chromatography Flame Ionization Detection (GC-FID). protocols.io https://dx.doi.org/10.17504/protocols.io.36wgqjerovk5/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License,  which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: February 07, 2023
Last Modified: August 21, 2023
Protocol Integer ID: 76618
Keywords: Reductive Catalytic Fractionation, Gas Chromatography
Funders Acknowledgement:
U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy and Bioenergy Technologies Office (BETO)
Grant ID: DE-AC36-08GO28308
Abstract
A gas chromatography with flame ionization detection (GC-FID) method was developed to quantify reductive catalytic fractionation (RCF) monomers.

Guidelines
NOTICE
This work was authored by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Bioenergy Technologies Office. The views expressed herein do not necessarily represent the views of the DOE or the U.S. Government.

Materials
Woody RCF Standards
ReagentPhenol
ReagentGuaiacol
Reagent4-Ethylphenol
Reagent4-Methylguaiacol
Reagent4-Ethylguaiacol
ReagentSyringol
Reagent4-Propylguaiacol
ReagentIsoeugenol
ReagentMethylparaben
Reagent4-Ethylsyringol
Reagent4-Propylsyringol
Reagent4-Propanolguaiacol
ReagentPropenylsyringol
Reagent4-Propanolsyringol

Non-Woody RCF Standards
ReagentMethyl-3-(4-hydroxyphenyl) propionate ReagentMethyl-3-(4-hydroxy-3-methoxyphenyl) propionate ReagentMethylcoumarate
ReagentMethylferulate

Internal Standard
ReagentTri-tert-butylbenzene

Reagents
ReagentMethanolP212121Catalog #PA-33900HPLCCS4L



Equipment

Equipment
Gas Chromatograph
NAME
8890 GC System
TYPE
Agilent
BRAND
8890 GC System
SKU
LINK

Equipment
HP5-MS
NAME
GC Column
TYPE
Agilent
BRAND
19091S-433UI
SKU
LINK

Equipment
Inlet Liner
NAME
Agilent
BRAND
5183-4711
SKU
LINK
Inlet liner, split, single taper, glass wool, deactivated
SPECIFICATIONS


Safety warnings
All chemicals used for this procedure are hazardous. Read the Safety Data Sheet (SDS) for all chemicals and follow all applicable chemical handling and waste disposal procedures. Manufacturer specific SDS information can be found by following the CAS numbers of compounds in 'Materials' list.
Before start
All solvents, analytes, and chemicals used in this protocol are listed in the 'Materials' section. They are excluded from in-line referencing to keep steps clear and concise.
Internal Standard Preparation
Internal Standard Preparation
This analysis uses 1,3,5-tri-tert-butylbenzene (TTB) as an internal standard. Prepare adequate volume to allow for addition of 1µL of TTB per 100 µL of sample or standard volume.

Create a 10,000 µg/mL internal standard working solution by weight of TTB using methanol as the diluent.

Preparation of Standards
Preparation of Standards
By weight, create individual 20,000 µg/mL stock solutions of all monomers (listed in Materials section) and use methanol as the diluent.


Note
If compounds have not previously been analyzed on the column specified in this method, it is necessary to analyze each monomer separately (at a concentration of approximately 100 µg/mL) to determine retention time for each before analyzing a mixture containing all compounds.

Combine the stock solutions to create a 1000 µg/mL mixed standard working solution in methanol.

For example, to prepare a 10 mL mixed standard working solution of woody RCF analytes (distinguished in Materials section), add 500 µL of each of the 20,000 µg/mL stock solutions (14 analytes) and add 3000 µL methanol.

Using the mixed standard working solution at 1000 µg/mL, create a calibration curve from 10 µg/mL to 1000 µg/mL with a minimum of five calibration points using methanol as the diluent.

Add 1 µL of 10,000 µg/mL TTB internal standard working solution per every 100 µL of calibration standard.
Example: 10 µL into 1000 µL or 5 µL into 500 µL

Example Calibration

Sample Preparation
Sample Preparation
Oil Samples:
  1. Weigh approximately 5-10 mg of oil into a GC vial and record weight.
  2. Add a known volume of methanol to each vial containing sample (for example 1 mL).
  3. Add 1 µL of 10,000 µg/mL TTB for every 100 µL of methanol added to the sample vial.
Example: 10 µL into 1000 µL or 5 µL into 500 µL

Liquid Samples:
  1. Aliquot a known volume of sample into a GC vial (for example 1 mL)
  2. Add 1 µL of 10,000 µg/mL TTB for every 100 µL of methanol added to the sample vial.
Example: 10 µL into 1000 µL or 5 µL into 500 µL

GC-FID Analysis
GC-FID Analysis
Analyze samples using an 8890 Agilent Gas Chromatograph (GC) or equivalent equipped with a flame ionization detector (FID) per the method parameters below:
Method Parameters

Split/Splitless Inlet Parameters:
Inlet Temperature: 280 °C
Injection Volume: 1 µL
Split Ratio: 2:1
Inlet Liner: split, single taper, glass wool, deactivated (see Materials)
Syringe: P/N 5181-8809
Wash Solvent: Methanol

Column:
HP5-MS (see Materials)
Carrier Gas: Helium
Flow Rate: 1 mL/min (constant flow)

Oven Parameters:
Maximum Oven Temperature: 280 °C


Detector Parameters:
Detector: FID
Detector Temperature: 300 °C
Air Flow: 400 mL/min
H2 Fuel Flow: 40 mL/min
Makeup Flow: 10 mL/min





Analytical Quality Control
Analytical Quality Control
Several strategies are utilized when performing this analysis to ensure instrument stability and reproducibility.
Calibration Curves
All compounds must have a correlation coefficient (r2) of 0.995 or greater using a linear calibration fit.
Calibration Verification Standards (CVS)
A calibration verification standard (CVS) is a standard from the calibration curve that is re-analyzed every 20 or fewer samples to ensure instrument drift remains within the determined acceptance criteria. Acceptable CVS recoveries for this analysis are within 15% of the expected amount. Acceptance criteria may differ between instruments and should be determined experimentally.