Turbomatrix atd

After the extraction onto preconditioned glass traps (4 mm i.d., 6 mm o.d., and 89 mm long) packed with Tenax TA (Supelco, Bellefonte, PA) as described above (but from 20 ml of melon juice), the trap was desorbed onto a HP-5MS column (30 m × 0.25 mm × 0.25 μm film thickness) in an Agilent 7890A/5975C GC–MS (Agilent, Santa Clara, CA), equipped with an automated thermal desorber (Turbomatrix ATD; Perkin Elmer, Waltham, MA) and fitted with an ODO 2 GC–O system (Scientific Glass Engineering Ltd.). After desorption, the oven was maintained at 40 °C for a further 2 min and then the temperature was raised at 4 °C/min to 300 °C. The mass spectrometer was operated in the electron impact mode with a source temperature of 230 °C, an ionising voltage of 70 eV, and a scan range from m/z 20 to 400. Two assessors were used for the detection and verbal description of the odour-active components of extracts and only those odours which were detected by both assessors were recorded in the results. The assessors scored each odour on a seven-point line-scale (2–8) where 3 = weak, 5 = medium and 7 = strong. n-Alkanes C₆–C₂₅ were analysed under the same conditions to obtain linear retention index (LRI) values for the components.

Emitted volatiles were collected from rose flowers by dynamic headspace sampling and were sent through a glass tube filled with TENAX TA resin (60/80 mesh, 250 mg, Perkin Elmer) at 100 ml/min for 6 h²³. The volatiles were analyzed by GC-MS connected to the Thermodesorption System (TurboMatrix ATD, Perkin Elmer). All peaks were assigned by reference to the NIST library.

BVOC sampling procedure and quantitative method were as described in Chen et al. (2019) [21 (link)]. The healthy leaves were carefully enclosed in a glass sampling chamber (Figure 2). The BVOCs emitted from leaves to the chamber were collected with sampling tubes (200 mg Tenax TA, mesh 60/80, Supelco, Bellofonte, PA, USA), installed in a modified autosampler (STS-25^®; PerkinElmer, Waltham, MA, USA) with 150 mL min⁻¹ flow rate for BVOCs to flow into the absorbent. Each sampling tube collected BVOCs emitted for a period of 60 min, every h during daytime (04:00–16:00) and every 2 h during nighttime (18:00–04:00), with 8.25 L BVOCs collected per sample tube. BVOC sampling tubes were brought back to laboratory every day for analysis on contents and concentrations of BVOCs. The sample tube was analyzed using gas chromatography mass spectrometer (GC-MS) (Clarus 600 GC-MS system, PerkinElmer Instruments, USA) equipped with a thermal desorption system (Turbo Matrix ATD, PerkinElmer Instruments, USA). The data of 17 sampling tubes in one day were combined to represent the BVOCs emitted by the sapling. After sampling, shoots in the sampling chamber were cut, then placed in 100 °C for 48 h, and finally weighed to obtain the absolute dry biomass.