# US 12,000,809 B2 · Zwitterionic compounds as gas chromatographic column stationary phases

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,000,809 B2
- Document ID: US12000809B2
- Status: Granted
- Kind: B2
- Application number: 17/662,512
- Filed: 2022-05-09
- Published: 2022-08-25
- Granted: 2024-06-04
- Earliest claimed: 2018-05-24
- Assignees: Iowa State University Research Foundation, Inc.
- Applicants: Iowa State University Research Foundation, Inc.
- Inventors: Jared L. Anderson; Kosuke Kuroda; He Nan
- Web page: https://patentgrep.com/patent/US12000809B2

## CPC

- G01N 30/56: Packing methods or coating methods
- B01D 15/36: involving ionic interaction, e.g. ion-exchange, ion-pair, ion-suppression or ion-exclusion
- B01J 20/281: Sorbents specially adapted for preparative, analytical or investigative chromatography
- C07D 233/60: with hydrocarbon radicals, substituted by oxygen or sulfur atoms, attached to ring nitrogen atoms
- G01N 30/68: Flame ionisation detectors
- G01N 30/72: Mass spectrometers {(mass spectrometers per se H01J49/00)}
- G01N 30/74: Optical detectors {(measurement of intensity, velocity, spectral content, polarisation, or phase of infrared, visible or ultraviolet light G01J)}
- G01N 2030/025: {Gas chromatography}
- G01N 2030/562: {packing}
- G01N 2030/884: {organic compounds}
- G01N 2030/889: {monitoring the quality of the stationary phase; column performance}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

A gas chromatographic (GC) column using a zwitterionic compound and methods of use thereof are disclosed herein. The volatile free acids were observed to strongly retain on these zwitterionic compounds-based columns with excellent peak symmetry. By carefully tuning the structures of these zwitterionic compounds, different selectivity toward volatile free acids was demonstrated. These stationary phases possess a wide working range with thermal stabilities at higher temperatures.

## Claims

### Claim 1

A method of chromatographic analysis or separation, the method comprises:
separating an analyte by a column; wherein the column comprises a zwitterionic compound as its stationary phase,
wherein the zwitterionic compound is a molecule represented by a formula:
or mixture thereof,
wherein R1-R5 are independently H, halogen, —NR′R″, —NO2, —COOR′, —CHO, —OR′, —PO3H, —PO3R′, —PO3R′R″, —SO3R′, —SO2, SO3H, —SR′, substituted alkyl group, or unsubstituted alkyl group; and wherein R′ and R″ are independently H or an alkyl group; and
wherein at least one of R2 and R1 is a sulfonate or phosphonate, a group containing a —SO3 or P(OR6)O2− group; where R6 is H or substituted or unsubstituted alkyl group or anion thereof.

### Claim 2 (depends on 1)

The method of claim 1, wherein the column is at a temperature from about 0° ° C. to about 120° C.

### Claim 3

A method for gas chromatographic (GC) separation or analysis of an organic molecule, wherein the method comprises:
inputting a sample into a gas chromatographic (GC) column,
wherein the column comprises a zwitterionic compound as its stationary phase;
wherein the zwitterionic compound is a molecule represented by a formula
or mixture thereof,
wherein R1-R5 are independently H, halogen, —NR′R″, —NO2, —COOR′, —CHO, —OR′, —PO3R′, —PO3R′R″, —SO2, —SO3R′, —SR′, or unsubstituted alkyl group; and wherein R′ and R″ are independently H or an alkyl group;
wherein at least one of R2 and R1 is a sulfonate, phosphonate, or a group containing a —SO3″ or —P(OR6)O2− group; where R6 is H, or substituted or unsubstituted alkyl group; or anion thereof; and
wherein the sample comprises an organic molecule.

### Claim 4 (depends on 3)

The method of claim 3, wherein the organic molecule is not derivatized before the sample is input into the GC column.

### Claim 5 (depends on 3)

The method of claim 3, wherein the organic molecule is a C1-C30, C1-C20, C1-C15, C1-C10, C1-C6 ester, alcohol, free acid, ether, aldehyde, amine, or mixture thereof and is volatile at room temperature or a temperature from about 0° ° C. to 50° C.

### Claim 6 (depends on 3)

The method of claim 3, the method further comprises detecting or quantifying the organic molecule by FID, UV, or mass spectrometry (MS) measurement.

### Claim 7 (depends on 3)

The method of claim 3, wherein the gas chromatographic (GC) column has a length of from about 0.5 m to 60 m, a diameter of from 100 μm to about 560 μm, and a coating thickness of from 0.05 μm to 0.5 μm.

### Claim 8 (depends on 3)

The method of claim 3, wherein the GC column is at a temperature of from about 0° ° C. to about 120° C.