GC-MS Analysis | EUROLAB

What Is GC-MS Analysis?

GC-MS is a hybrid technique in which components separated by gas chromatography are fed to a mass spectrometer, ionised, and identified by their fragmentation pattern. Chromatography provides the separation, and mass spectrometry the identification.

Purpose of GC-MS Analysis

The purpose is not only to separate the components of a mixture but also to determine which compounds they are via the mass spectrum. Since the resulting spectrum can be compared against libraries, previously unknown compounds can also be identified; this underlies screening studies.

Which Products Is GC-MS Analysis Applied To?

Phthalate and restricted-substance screening in toys and consumer products
Components migrating from packaging into food
Volatile organic compounds in automotive interior materials
Pesticide and PAH screening in environmental samples
Allergenic fragrance components in cosmetics

In Which Sectors Is GC-MS Analysis Used?

ChemistryPharmaceuticalsFoodCosmeticsEnvironmentToyAutomotivePackaging

Standards Related to GC-MS Analysis

ISO 18856 / ISO 18857 (water quality — determination of phthalates and PAHs)
EN 14372 (phthalates in childcare articles)
ISO 16000-6 (VOCs in indoor air — GC-MS)
IEC 62321-8 (determination of phthalates in electrotechnical products)
ISO 17353 / EPA 8270-type semi-volatile organic compound methods

GC-MS Analysis Conditions

ionization: Electron ionization (EI) is common; chemical ionization is an option
Tarama modu: Full scan or SIM (selected ion monitoring) — depending on purpose
Column and temperature program: From the applied method standard
Library: Spectrum library match supports identification, alone is not confirmation

Equipment for GC-MS Analysis

gas chromatograph
Single quadrupole mass spectrometer
Electron ionisation source
Spectral library and data processing software
Headspace / thermal desorption unit

Sample Requirements for GC-MS Analysis

Solvent extraction is applied for solid samples, and dilution or liquid-liquid extraction for liquids
Plastic containers must not be used for common contaminant analyses such as phthalates
Sample quantity varies by matrix
If a suspected compound group is stated, the method is selected accordingly

Duration of GC-MS Analysis

A run in screening analyses generally does not exceed an hour; with sample preparation and confirmation work, routine duration is a few working days.

GC-MS Analysis Procedure

1The sample is extracted and cleaned up using a method suited to the matrix.
2Extract concentration is adjusted and an internal standard is added.
3Separation is performed on the GC column.
4The column outlet is fed to the mass spectrometer and components are ionised.
5The spectrum is recorded in full scan or SIM mode.
6Identification is made by comparing spectra with the library and a reference standard.
7Quantitation is performed via the calibration curve and internal standard.

GC-MS Analysis Acceptance Criteria

A method produces a result; it does not set a limit. Whether the result is acceptable is determined by the regulation or specification the product is subject to.

Evaluation of Results

Identification relies on the joint agreement of retention time and mass spectrum. A library match is only a preliminary assumption; definitive confirmation requires comparison with a reference standard under the same conditions. Using an internal standard for quantitation reduces the matrix effect.

GC-MS Analysis Report

Sample description, receipt date and laboratory number
Method applied and reference standard, if any
Instrument and measurement conditions
Sample preparation steps
Measurement results and units
Measurement uncertainty (if requested)
A statement that the results relate only to the sample submitted for testing

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

EU REACH Annex XVII (phthalate restrictions)
EU 2011/65/EU RoHS (including phthalates)
EN 71-3 / EN 71-9 (toy safety)
EU 1935/2004 (materials in contact with food)

Pages Where This Method Is Used

Analytical Methods — What Does This Group of Methods Do?

The section below describes the field that the GC-MS Analysis test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Analytical method pages are pages about a MEASUREMENT TECHNIQUE rather than about a test. The difference matters: "salt spray testing" is a test and answers one question; "ICP-MS" is a technique and is used in dozens of different tests. Sometimes the user is looking not for the test but for the technique — because the method name is what appears in their specification.

This distinction becomes decisive in choosing a laboratory. When a customer asks for "heavy metal analysis", the real question is by which technique it will be done: XRF is fast and non-destructive but does not distinguish compounds; AAS is economical for a single element; ICP-OES screens multiple elements; ICP-MS sees trace levels. The same sample gives results with different detection limits and different uncertainties across the four techniques.

Method selection is made against three criteria. DETECTION LIMIT: is the concentration sought within the range the method can see? MATRIX COMPATIBILITY: is the sample matrix (plastic, food, soil, metal) one the method can handle, and is pre-treatment required? SPECIFICATION LINK: does the product standard or legislation mandate a particular method? The third often overrides the first two — the specification binds the method.

Method pages build a CHAIN. A technique is linked to the test pages where it is used, to the standards those tests rest on, to the legislation those standards are tied to and ultimately to market access regimes. The example chain in the source document works like this: XRF → metal analysis → RoHS compliance → heavy metal restriction → coating pages. Whichever link the user enters from, they reach the others.

Sample preparation is the invisible half of the result in this family and is a greater source of error than the technique itself. The digestion method, degree of grinding, extraction solvent and dilution ratio change the result markedly. The same sample on the same instrument gives a different result with different preparation; the definition of the method therefore covers preparation too.

Calibration and verification are the third determining component. An instrument is calibrated with certified reference material, the calibration curve is verified periodically and a control sample is run in each batch. Without these steps, a number produced is not traceable even if the instrument is working correctly.

Method groups in this field

Elemental analysis
ICP-OES, ICP-MS, AAS and XRF. They differ in detection limit, matrix tolerance and multi-element capacity.
Chromatography
GC, GC-MS, HPLC, LC-MS/MS and ion chromatography. It separates a mixture into its components and measures each separately.
Spectroscopy
FTIR, Raman, UV-Vis and optical emission. For material identity, functional group identification and alloy composition.
Thermal analysis
DSC, TGA, DMA and dilatometry. Transition temperatures, composition, decomposition and dimensional behaviour.
Microscopy and imaging
Optical microscopy, SEM-EDS, radiography and tomography. Structure, defects and elemental distribution.
Classical (wet) chemistry
Titration, gravimetry and colorimetry. Used as a reference method and in confirming instrumental results.

Commonly confused in this field

XRF is a screening tool; it sees elements and does not distinguish compounds. A decision on a restricted compound requires confirmation by wet chemistry.
The phrase "not detected" is not proof of absence; it is read together with the detection limit of the method.
The specification binds the method. A technically better method is not accepted if the specification calls for another.
Sample preparation is part of the result; a report that does not state the preparation is not reproducible.
Results obtained by different techniques cannot be compared directly; their detection limits and uncertainties differ.
A method page is not a test page; which method applies to which test comes from the product standard.

Which decisions these results support

Matching the method written in the specification to the laboratory's scope
Method selection according to detection limit and matrix compatibility
Confirming an instrumental result with a reference method
Eliminating deviations arising from sample preparation

Related Tests

Frequently Asked Questions About GC-MS Analysis

Is a library match alone sufficient?

No. A library match is a strong clue but not confirmation. The compound must give the same retention time and spectrum as the reference standard under the same conditions.

What is the difference between screening and targeted analysis?

Screening investigates a broad group of compounds without knowing beforehand what is in the sample. In targeted analysis, the sought compounds are known from the outset and the method is validated for them; the limit of quantification is lower.