Monoterpenes released from fruit, plant, and vegetable systems

Area of Science:

• Environmental Chemistry
• Plant Science
• Analytical Chemistry

Background:

• Monoterpenes (MTs) are volatile organic compounds emitted by plants with diverse ecological roles.
• Understanding MT emission rates from various natural sources is crucial for atmospheric chemistry and plant physiology research.

Purpose of the Study:

• To quantify the emission rates of monoterpenes (MTs) from a range of fruit, plant, and vegetable (F/P/V) samples.
• To identify the predominant MTs emitted by different F/P/V sources and compare their emission profiles.

Main Methods:

• Utilized the sorbent tube (ST)-thermal desorption (TD) method coupled with gas chromatography for MT collection and detection.
• Employed an impinger-based dynamic headspace sampling system for measuring MT emission rates from F/P/V samples.
• Validated MT calibration using mass spectrometry (MS) and flame ionization detector (FID), achieving high coefficients of determination (R2 > 0.99).

Main Results:

• Identified α-pinene, β-pinene, myrcene, α-terpinene, R-limonene, γ-terpinene, and p-cymene as common MTs across 10 diverse F/P/V samples.
• Observed that R-limonene dominated emissions (>90%) from citrus fruits and beverages.
• Found distinct major MTs for other samples: α-pinene (37%) in carrots and myrcene (31%) in pine needles.

Conclusions:

• The study successfully quantified MT emission rates from various F/P/V sources using a reliable ST-TD-GC method.
• Confirmed a common set of MTs (α-pinene, β-pinene, myrcene, α-terpinene, γ-terpinene) across samples but highlighted significant differences in emission profiles between fruits, vegetables, and plants.
• The findings provide valuable data for atmospheric modeling and understanding plant-specific volatile organic compound emissions.