Polyamide SPE Tubes for Nonaqueous Sample Purity

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Solution Overview

Problem

Traditional polypropylene and high density polyethylene SPE tubes dissolve or leach contaminants into nonaqueous liquids during sample preparation, making them unsuitable for inert sample handling.

Innovation Solution

Polyamide, specifically nylon, is used to construct sample preparation tubes, which are inert and do not leach contaminants into nonaqueous liquids, with a hollow tube design containing an extraction medium and fritted glass filters, and optionally a polyamide screen.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If polypropylene or high density polyethylene tubes are used for SPE, then the tubes are easy to manufacture and traditionally considered clean, but they dissolve or leach contaminants into nonaqueous liquids

Engineering Contradiction:

Improveease of manufactureVSAvoidcontaminant leaching

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material parameter from polypropylene or high density polyethylene to polyamide (nylon), which fundamentally alters the chemical properties of the tube material. This parameter change resolves the contradiction by providing a material that does not leach contaminants into nonaqueous liquids while remaining manufacturable through conventional processes

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite structure combining polyamide tube material with fritted glass filters and optional polyamide screens. This composite approach maintains the ease of manufacture through standardized components while the polyamide material specifically addresses the contaminant leaching issue with nonaqueous liquids

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If polypropylene tubes are used for SPE, then they are traditionally considered clean and easy to use, but they are not chemically inert to nonaqueous liquids

Engineering Contradiction:

Improveease of operationVSAvoidchemical inertness

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent changes the chemical composition parameter from polypropylene to polyamide, which fundamentally improves chemical inertness toward nonaqueous liquids. This material substitution maintains ease of operation through similar handling procedures while resolving the reliability issue of chemical inertness

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If traditional SPE tubes are used with nonaqueous liquids, then the procedure is simple, but contaminants are dissolved or leached from the tube material

Engineering Contradiction:

Improvedevice complexityVSAvoidcontaminant dissolution

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material parameter to polyamide, which eliminates contaminant dissolution and leaching into nonaqueous liquids. This single material change maintains device simplicity while resolving the harmful contaminant generation issue

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent transforms the potential harm of contaminant leaching by selecting polyamide material that is specifically resistant to nonaqueous liquids. The material property that would normally be considered (chemical resistance) is leveraged to convert a harmful interaction into a beneficial inert interaction

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 polyamide tubes maintain sample purity by minimizing contaminant leaching, as demonstrated by reduced contaminants in chromatograms compared to polypropylene and high density polyethylene tubes, with improved inertness similar to TEFLON® tubes.

Implementation Method 1

The polyamide tube has both an inlet and an outlet and, in various implementations, the extraction medium may be contained between an inlet-side fritted glass filter and an outlet-side fritted glass filter

Methodology Applied

Scientific EffectFiltration: Filter (physical)

Implementation Method 2

adsorbing one or more analytes present in the sample to be analyzed to the conditioned extraction medium

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 3

the inventors show herein that when using a nonaqueous liquids, contaminants are dissolved or leached from polypropylene SPE tubes and from high density polyethylene SPE tubes as well. Thus, there is a need for SPE tubes that are substantially inert and do not dissolve or leach contaminants into nonaqueous liquids

Methodology Applied

Scientific EffectChemical inertness:

Data Source

PatentUS8883089B2Sample preparation device and method utilizing polyamide tube

Publication Date: 2014.11.11 AGILENT TECHNOLOGIES INC

AI summary

Polyamide sample preparation tubes with a hollow polyamide tube and an extraction medium contained within the tube are utilized in the sample preparation devices. The sample preparation tubes are substantially inert and show little tendency to dissolve or leach contaminants into nonaqueous liquids. The polyamide tubes may be used in preparing samples for analytical procedures such as GC, GC/MS, LC or LC/MS.