Diffusion Denuder for Semivolatile Organic Chemical Sampling

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Solution Overview

Problem

Conventional methods for sampling and analyzing semivolatile organic compounds (SOCs) in ambient air face challenges such as incomplete phase separation, high sample turn-around time, solvent usage, and increased opportunities for analyte losses, particularly in high-volume and passive sampling techniques, which are costly and unsustainable.

Innovation Solution

A system comprising a multicapillary collection device, a hot gas spike apparatus, and an analyte transfer apparatus that separates and collects gaseous and particle-associated SOCs using diffusion denuders, allowing for thermal extraction and transfer of analytes into minitubes for analysis, reducing sampling time and solvent usage while enabling efficient cleanup and quantitative transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high-volume sampling is used to collect sufficient quantities of analytes, then the quantity of substance collected is improved, but the loss of time and use of energy increase due to long sampling periods and extensive solvent extraction procedures

Engineering Contradiction:

Improvequantity of analytes collectedVSAvoidsampling and analysis time

Core Design Contradiction:

Quantity of substanceVSLoss of time

Solution Approach 1:

The invention extracts only the necessary analytes from the air sample using a compact sorbent trap, eliminating the need for large-volume sampling and extensive solvent extraction procedures. The sorbent trap selectively captures target compounds directly from the air stream, providing sufficient analyte quantity for analysis without requiring hours to days of sampling time.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical solvent extraction system with thermal desorption. Instead of using liters of solvent to extract analytes from large sample volumes, the system uses controlled heating to desorb analytes directly from the sorbent trap into the gas chromatograph, dramatically reducing both time and material requirements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If solvent extraction is used to liberate collected analytes from sampling media, then the ease of operation is improved, but the loss of substance increases due to sample dilution and required concentration steps

Engineering Contradiction:

Improveanalyte liberation from sampling mediaVSAvoidanalyte loss during extraction and concentration

Core Design Contradiction:

Ease of operationVSLoss of substance

Solution Approach 1:

The invention replaces solvent extraction with thermal desorption, eliminating the dilution effect inherent in solvent-based methods. Analytes are liberated from the sorbent trap through controlled heating and directly transferred to the gas chromatograph via carrier gas, avoiding the need for concentration steps that can lead to analyte loss.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention uses a carrier gas as an intermediary to transfer analytes from the sorbent trap to the gas chromatograph. This intermediary medium allows for efficient analyte transport without the dilution and loss associated with solvent extraction and evaporation processes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If conventional high-volume sampling with particulate filter anterior to vapor phase sorbent is used, then the separation of particle and vapor phases is attempted, but the measurement precision deteriorates due to sampling artifacts that confound differentiation

Engineering Contradiction:

Improvephase separation capabilityVSAvoidphase differentiation accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The invention segments the sampling system into distinct functional zones: a particle filter section that removes particulate matter, followed by a vapor phase sorbent trap section that captures gaseous compounds. This segmentation allows for clean separation of particle and vapor phases without the artifacts that occur when phases interact in conventional single-stage samplers.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system achieves faster sampling times with reduced solvent consumption and analyte losses, providing efficient and cost-effective separation and analysis of SOCs in both gas and particulate phases, comparable to conventional methods, while being more sustainable and minimizing artifacts.

Implementation Method 1

various passive methods that rely on diffusion of SOCs into the trapping medium to gather analytes in the absence of advection

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

allowing for thermal extraction and transfer of analytes into minitubes for analysis

Methodology Applied

Scientific EffectThermal extraction: Desorption

Data Source

PatentUS9335306B2Semivolatile organic chemical sampling and extraction transfer method and apparati

Publication Date: 2016.05.10 PERLINGER JUDITH A

AI summary

An apparatus for collecting semivolatile organic chemicals (SOCs) from an atmosphere comprising a housing having an inlet and an outlet and at least one diffusion denuder contained in the housing. The at least one diffusion denuder has a plurality of capillaries coated with a stationary phase for capturing gaseous SOCs.