GC-MS/MS Analysis

What Is GC-MS/MS Analysis?

GC-MS/MS is a system with two mass analysers placed after the gas chromatograph. The first analyser selects the target compound's precursor ion, the collision cell fragments this ion, and the second analyser monitors the resulting product ions. This two-stage selectivity largely eliminates matrix noise.

Purpose of GC-MS/MS Analysis

The purpose is to reliably measure target compounds at very low concentrations in samples with intense matrix interference. Isobaric interferences that single-stage MS cannot distinguish are eliminated by monitoring the precursor-product ion transition.

Which Products Is GC-MS/MS Analysis Applied To?

Pesticide residues in food and feed
Persistent organic pollutants in soil and sediment
Mineral oil components in packaging and food-contact materials
Residue screening in tobacco and plant products

In Which Sectors Is GC-MS/MS Analysis Used?

ChemistryPharmaceuticalsFoodCosmeticsEnvironmentAgriculturePackaging

Standards Related to GC-MS/MS Analysis

EN 15662 (QuEChERS — pesticide residues in plant-based food)
SANTE guidance (method performance in pesticide residue analyses)
ISO 17025 (competence of testing laboratories)

GC-MS/MS Analysis Conditions

viewing mode: MRM — at least two ion transitions per target compound
collision energy: Optimized in method development for each pass
Ion ratio: For confirmation, the consistency of the inter-pass ratio with the reference is sought.
Sample preparation: Usually QuEChERS or equivalent extraction and cleanup

Equipment for GC-MS/MS Analysis

gas chromatograph
Triple quadrupole mass spectrometer
Collision cell
Automated sample preparation and SPE units
Data processing and MRM library software

Sample Requirements for GC-MS/MS Analysis

A representative sample is required; homogenisation directly affects the result in residue analysis
A few hundred grams of raw sample are generally requested for plant-based food
The sample must be sent in the cold chain and protected from light
The sought residue group (pesticide package) must be defined in advance

Duration of GC-MS/MS Analysis

A run takes between half an hour and an hour. Because of QuEChERS preparation and confirmation of many target compounds, routine reporting time is a few working days.

GC-MS/MS Analysis Procedure

1The sample is homogenised and weighed.
2Extraction and clean-up (e.g. QuEChERS) are applied.
3Internal standard and matrix-matched calibration are prepared.
4The extract is injected onto the GC column.
5MRM transitions are monitored for the target compounds.
6Confirmation is made by comparing ion ratios with the reference.
7Recovery and blank checks are assessed.

GC-MS/MS Analysis Acceptance Criteria

Whether a residue result is acceptable is determined by maximum residue limits; these limits come from the relevant food and agriculture regulation, not from the method.

Evaluation of Results

For confirmation, in addition to retention-time agreement, at least two ion transitions and their ratio must match the reference standard. Matrix-matched calibration is used if the matrix effect is significant.

GC-MS/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 396/2005 (pesticide residue limits)
Turkish Food Codex Pesticide Residues Regulation
EU 2017/625 (official controls)

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/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/MS Analysis

Why is MS/MS more reliable than single-stage MS?

Because it performs two-stage mass selection, interferences from the matrix are largely eliminated. This means both a lower limit of quantification and fewer false-positive results.

How many pesticides can be screened at once?

The number depends on the laboratory's validated package. The method only gives results for validated compounds; a substance outside the package cannot be reported.