Aoc 20i injector

Residual solvents and ethanol were quantified by gas chromatography using a GC-2010 Plus AF system equipped with an AOC-20i injector for automated sample injection (both from Shimadzu). The product solution was mixed with an equal amount of internal standard (40.000 μg/ml n-propanol) and applied on to a (5%-Phenyl)-methylpolysiloxan column (HP-5, 30 × 0.53 mm; Agilent). Separation of analytes was achieved with the following parameters: FID temperature: 260 °C, inlet temperature: 250 °C, mode: split, carrier gas pressure: 20 kPa, purge flow: 3.0 ml/min, split ratio: 6.0, temperature program: 0–3 min @ 55 °C, gradient from 3 to 6 min of 55 to 200 °C, 6–12 min @ 200 °C. Results were analyzed using Chromeleon 6.8 Chromatography Data System Software (Thermo Fischer Scientific) and a sample volume of 0.3 μL.

A Shimadzu GC-MSQP2010 fitted with a AOC-20i injector and FID and MS detectors (Shimadzu, Tokyo, Japan) was used for the GC-MS analysis. The GC was run with a nonpolar Supelco MDN-5S fused silica capillary column (30 m × 0.25 mm ID, 0.25 µm film thickness) commonly used for the analysis of VOCs. The injection volume (EO dissolved in chromatography grade hexane) was 1 μL. Helium was used as the carrier gas at a constant flow of 1 mL/min. The column temperature was set at 50 °C for 30 s, then increased from 50–150 °C at 4 °C/min, from 150–175 °C at 1.5 °C/min and from 175–300 °C at 20 °C/min for a total analysis time of 58.42 min. The injector temperature was set to 250 °C and the injection was accomplished with a split ratio of 1/50 throughout the entire run. The MS was operated in the electron impact mode at 70 eV, with a scan range of 40–400 m/z. The temperatures were set to 200 °C for the ion trap, 50 °C for the manifold and 305 °C for the transfer line.
A Varian 450-GC fitted with an MS240 iontrap MS and a Combipal autosampler (Varian Instruments, Sunnyvale, CA, USA) and run with a nonpolar Varian FactorFour VF-5ms column (30 m × 0.25 mm ID, 0.25 μm film) commonly used for the analysis of VOCs was used under the same conditions to assist in compound identification.

Gas chromatography separation method was employed to detect GC-amenable LM from liquid samples and quantify its content via standard calibration. Payload (P_%) and Encapsulation efficiency (EE_%) were determined according to Baiocco, Preece and Zhang [10 (link)]. Air-dried LM-microcapsules (2.5 mg) were suspended in absolute ethanol as the receptor medium (50 mL) within airtight glass vials which were ultrasonicated (VWR Ultrasonicator, USC200TH, Lutterworth, UK) over 60 min to rupture the microcapsule shells hence releasing their oil load. Subsequently, the LM-abundant phase (supernatant) was separated by centrifugation (Sigma 3-18KS, Buckinghamshire, England, UK) and transferred into an automatic parse screw-top amber glass vial (Agilent Technologies, 9-425, CA, US) specially designed for GC. The GC system was a Shimadzu GC-2010, with AOC-20i Injector and AOC-20s Auto-sampler, (Shimadzu UK Ltd., Wolverton, UK) utilising nonane as the internal standard (IS). The column used was a Phenomenex ZB-5 (95% Polydimethyl siloxane/5% Polydiphenyl siloxane) connected to the gas cylinders of He, N₂, and compressed air as the carrier gases. Based on the response of LM to the specific detector in the column, the elution time of LM was 7.5 min. The experiments were performed in triplicate.