With that said, we’ve developed this handy guide to interpreting GC/MS data to help our customers-and anyone else who’s interested in knowing how to analyze a gas chromatogram. Your lab should be providing you with detailed insights and actionable recommendations in an easy to understand format something Innovatech Labs prides itself on. Gas chromatography mass spectrometry (GC/MS) analysis is an effective testing and troubleshooting tool for many manufacturers across industries, helping identify and quantify the materials that make up a sample or uncover contaminants that impact product quality.īut when it comes to making sense of GC/MS analysis results, you may wonder how to read a gas chromatogram or how to interpret the results. Critical Medical Device Testing Services.Hard Drive Microcontamination Testing Services.Quality Control Testing for Manufactured Products.Outgassing Testing Services Prevents Critical Errors.Materials Characterization & Specialized Testing.Material Testing Services for Products and Components.Cleanliness Testing for Microcontamination.Thermal Gravitational Analysis (TGA) Lab Services.Electron Spectroscopy for Chemical Analysis (ESCA).Gas Chromatography Mass Spectrometry (GC/MS).Fourier Transform Infrared Spectroscopy (FTIR).Differential Scanning Calorimetry (DSC) to Measure Heat Flow.A discussion of data analysis in modern systems is found in this article: Automated Analysis of Open-Access HPLC Instrumentation Metrics. Are the reference and internal standard peaks correctly identified, and the retention times OK?Īlthough the data is all recorded and calculations made for the analyst, it is the analyst’s job to make sure that no errors have been made.Is there the right number of peaks? Any extra or missing peaks?.Are the shapes of the peaks acceptable? Not too much asymmetry, nice and sharp and on-scale.Does the baseline look OK, flat with not too much noise?.The trace should always be checked, as this will be the first indication if anything has gone wrong with the chromatography. Reading a chromatogramĪlthough modern instrumentation has removed much of the guesswork from the paper and scissors days, the ability to read and interpret a chromatogram is just as important nowadays. Tricks like photocopying the trace and enlarging the trace could be used to increase precision.Īs can be imaged, overlapping peaks and samples containing lots of different constituents could cause an analyst serious problems. The peak area being proportional to the weight, provided the paper’s thickness and moisture content are uniform. Cutting and weighing:Ī baseline was constructed for the peaks that were recorded. This count was then used along with the detector’s attenuation and the sample composition was calculated. The number of squares in each triangle was then counted. The analyst used a ruler and pen to draw the best peak shape (triangle) and baseline. From the trace, there were two methods commonly used for working out the results: Counting squares: Square Paper and Scissorsīefore data analysis and digital integration become the standard - graph paper and scissors were to be found on every analyst’s shelf.Ī chart recorder, linked to the detector, recorded the trace directly onto square paper or graph paper using an ink pen. Nowadays it is very much an automated process to generate a results table, but it wasn’t always this simple. Results table (containing raw data and calculated data).Chart recording showing the peaks generated and the baseline, known as a trace.Filename and location of raw data generated during the run.Instrument identification and name of analytical method used.Sample information (weight or concentration of sample).Sample identification (Product, batch number, stage number).As an example, the minimum shown on a GC run of an in-process sample might be: There are many different variations on what is shown on a chromatogram - depending on the settings used in each laboratory and any regulatory requirements. It is an electronic file or hardcopy containing the information generated during the chromatography run. A chromatogram is essentially the output of a chromatography run.