A comparison of semi-quantitative methods suitable for establishing volatile profiles.

Area of Science:

• Analytical Chemistry
• Biochemistry
• Environmental Science

Background:

• Scent profiles from living tissues are analyzed using gas chromatography-mass spectrometry (GC-MS) and Headspace Sorptive Extraction.
• Absolute quantification of volatile organic compounds (VOCs) is challenging due to unpredictable compositions and lack of standards.
• Researchers often focus on relative abundance (scent footprints) rather than absolute quantities for scent profiling.

Purpose of the Study:

• To compare the efficacy of various semi-quantitative methods for VOC analysis in scent profiling.
• To determine if calibration curves are necessary for accurate relative quantification of VOCs.

Main Methods:

• Evaluation of semi-quantitative methods including external calibration curves, liquid addition of standards, total/normalized peak area per fresh weight, internal standard abundance, nearest n-alkane, and percentage of emission.
• Exploration of nearest components and single calibrators for semi-quantification.
• Comparison of results against true-standard quantification where applicable.

Main Results:

• Most semi-quantitative methods, except standard addition to the biological sample, yielded results comparable to true-standard quantification.
• Each method exhibited distinct advantages and disadvantages concerning accuracy, variability, and retrieved quantities.
• Statistical results from the studied semi-quantitative methods were highly similar.

Conclusions:

• Several semi-quantitative methods are valid for scent profiling, offering similar statistical outcomes.
• Generating calibration curves for each VOC is not essential for determining relative proportions.
• The choice of method depends on specific research needs regarding accuracy and experimental constraints.