PFAS Analysis by Combustion Ion Chromatography (CIC)

Combustion Ion Chromatography (CIC) is an important screen tool for analyzing Per- and Polyfluoroalkyl Substances (PFAS). While other methods like LC-MS/MS are used for targeted analysis of specific PFAS compounds, CIC gives a total measure of all organic fluorine in a sample, providing a comprehensive screening tool for the presence of PFAS.

Besides providing PFAS analysis solution per EPA Method OTM-50, Nutech also launched solution for solid and liquid sample utilizing Combustion Ion Chromatography (CIC) technology.

Nutech CIC system’s configuration is highly flexible. It can be an integrated CIC system allowing customers to operate the combustion furnace and IC in one software. It can also serve as the combustion furnace allowing customers to use exsiting IC or other IC that they prefer.

Technical Data

Integration of Combustion Furnace and IC into One Unit

Orignal IC can be removed and allowing customer to use other IC

Nutech CIC Working Principle

The samples are combusted with oxygen and water vapor in the combustion furnace, and the resulting gaseous compounds are absorbed by the absorption solution. The analytes dissolved in the absorption solution are then transferred to the ion chromatography system for determining the concentrations of halogens (fluoride, chloride, bromide, iodide) and sulfur.

Able to Work with Other IC

The system only serve as a high performance sample prep unit

High Automation

• System preparation: With one-key activation, the combustion furnace automatically heats up, and the IC module starts automatically.
• Sample introduction: Place the sample in the autosampler, input the required sample information and analytical method. The system will then automatically perform combustion pyrolysis according to the preset program.
• Analysis: The sample solution is automatically made up to volume and injected into the IC module, with the flow path automatically cleaned. Automatic dilution is optional for high-concentration samples.
• Results are automatically calculated, and blank values are automatically deducted.
• Troubleshooting: The system automatically prompts for faults and provides troubleshooting methods. Individual components can be tested separately via the manual detection interface.

High Efficiency

• Simultaneous sulfur and halogens determination, with automatic data calculation and direct LIMS upload minimizes manual errors.
• Calibration curves for various concentration ranges can be prepared to reduce repetitive testing.

Low Quantitation Limit

• Based on a 50mg sample, the limit of quantitation (LOQ) can be as low as 0.2 mg/kg(200ppb).

Module Design

• Enables easy replacement of combustion tubes, sampling rods, and chromatography column.
• Can serve as a complete CIC system or only a sample prep instrument for other IC

General Application of CIC

This combustion ion chromatography system is highly versatile and well-suited for the accurate determination of fluorine, chlorine, bromine, iodine and sulfur contents in solid, liquid, and gas samples.

Environmental: water, soil, paper

Plastics: degradable material, polymers(PP PE), rubber, plastic waste

Electronics: printed circuit boards, cables, insulating material, soldering material, OLED

Petrochemicals: crude oil, diesel, gasoline, catalysts

Mining: copper concentrate, iron ore, coal

Textiles: fabric, paints, waterproofing agent, auxiliaries, pigments

Foods: oils, spices, flavorings, fragrances

Application in PFAS Analysis

CIC’s main application in PFAS analysis is to determine the Total Organic Fluorine (TOF) in a sample. Here’s how it works:

Combustion: The sample (solid, liquid, or gas) is heated to a high temperature, typically around 1000°C, in a furnace. This process breaks down all the organic fluorine-containing compounds, including PFAS, into their ionic form, specifically fluoride (F−).

Absorption: The resulting gases are then absorbed into a liquid solution.

Ion Chromatography: The solution containing the fluoride ions is then analyzed by an ion chromatograph, which quantifies the total amount of fluorine present.

Targeted methods like LC-MS/MS can only identify and quantify the specific PFAS compounds for which standards are available. Since there are thousands of different PFAS compounds, many of which are unknown or lack standards, CIC can serve as a high efficient screening method by measuring TOF/AOF/EOF.

Determination of Fluorine in Perfluoroalkyl and Polyfluoroalkyl Substances(PFAS) – PFHxS

Test Procedure

Weigh an appropriate amount of PFHxS standard substance and dissolve it in methanol. Dilute to the desired concentration, then transfer an appropriate volume of the solution onto pre-fired quartz wool. Perform the test according to the established procedure, and calculate the recovery rate.

Table – Recovery Test Results for PFHxS

Chromatogram

System Blank Test

Ultra low detection limit

Test Procedure

Without adding any sample, follow the routine sample testing procedure and conduct multiple consecutive tests until the system blank no longer decreases. This value is defined as the minimum system blank of this instrument.

On a 50 mg sample, the system blank can be as low as 80ppb.

Table – System Blank Test Results

Chromatogram

Applicable International Standards and Methods

EPA Method 1621: Determination of Adsorbable Organic Fluorine (AOF) in Aqueous Matrices by Combustion Ion Chromatography (CIC)

DIN 38409-59: German Standard Methods for the Examination of Water, Wastewater, and Sludge – Part 59: Determination of Adsorbable Organically Bound Fluorine, Chlorine, Bromine, and Iodine (AOF, AOCl, AOBr, AOI) Using Combustion and Subsequent IC Measurement

ASTM D7359: Standard Test Method for Total Fluorine, Chlorine and Sulfur in Aromatic Hydrocarbons and Their Mixtures by Oxidative Pyrohydrolytic Combustion followed by Ion Chromatography Detection (Combustion Ion Chromatography-CIC)

ASTM D7994: Standard Test Method for Total Fluorine, Chlorine, and Sulfur in Liquid Petroleum Gas (LPG) by Oxidative Pyrohydrolytic Combustion Followed by Ion Chromatography Detection (Combustion Ion Chromatography-CIC)

UOP 991: Trace Chloride, Fluoride, and Bromide in Liquid Organics by Combustion Ion Chromatography (CIC)

IEC 62321-3-2/DIN EN 62321-3-2: Determination of Certain Substances in Electrotechnical Products – Part 3-2: Screening – Fluorine, Bromine and Chlorine in Polymer and Electronics by Combustion – Ion Chromatography

ISO/FDIS 18127: Water quality — Determination of adsorbable organically bound fluorine, chlorine, bromine and iodine (AOF, AOCl, AOBr, AOI) — Method using combustion and subsequent ion chromatographic measurement

ASTM D8247: Standard Test Method for Determination of Total Fluorine and Total Chlorine in Coal by Oxidative Pyrohydrolytic Combustion Followed by Ion Chromatography Detection

ISO 19242: Rubber — Determination of total sulfur content by ion chromatography

KS M 0180-2009: Standard test method for halogen (F, Cl, Br) and sulfur content by oxidative pyrohydrolytic combustion followed by ion chromatography detection (Combustion ion chromatography—CIC)

Nutech PFAS Analysis & Screening Solutions