Hplc grade hexane

OME racemate, (R)-OME, (S)-OME, and (S)-lansoprazole (I.S) were purchased from Sigma-Aldrich (Steinheim, Germany). HPLC-grade hexane, ethanol, formic acid, and ammonium hydroxide were purchased from Merck (Darmstadt, Germany). A Milli-Q Plus water purification system from Millipore Corporation (Bedford, USA) was used for water purification.

Technical-grade dodecyl acetate (DDA) (97%) was supplied by Merck Life Science S.L. (Madrid, Spain). Its molecular formula and selected properties are as follows: molecular formula, C₁₄H₂₈O₂; molecular weight, 228.37 g mol⁻¹; melting point, 150 °C at 15 mmHg; octanol/water partitioning (log K_ow), 5.88.
Commercially available bentonite obtained from Merck Life Science S.L. (Madrid, Spain) was used in this study.
The solvent used in the DDA extraction was HPLC-grade hexane obtained from Merck Life Science S.L. (Madrid, Spain). Sodium alginate (medium viscosity, 3.5 kg m⁻¹ s⁻¹ for 2% solution) and tripolyphosphate (90–95%) obtained from Merck Life Science S.L. (Madrid, Spain) and calcium chloride (95%) obtained from Panreac S.A. (Barcelona, Spain) were used in the preparation and evaluation of the CR formulations.

The tomato floral scent was collected using a dynamic headspace extraction device [40 (link)]. Prior to flowering, individual buds were isolated in fabric mesh bags (mesh diameter: 2 mm) to prevent visits by bees. Once the flowers opened in the next morning, they were placed in a polyethylene plastic cup (upper diameter: 490 mm, bottom diameter: 370 mm, height: 35 mm, volume: 35 mL) to collect scent. The flowers in the cups opened normally and were not jostled. Each cup contained an inlet and an outlet to let air in and out. The inlet was made in the middle of the lid of the cup. A vacuum pump (QC-1B, Beijing Institute of Labor Instrument, Beijing, China) was utilized to pull fragrant headspace air through sorbent traps at a flow rate of 1.5 mL/min. Air purified via an activated charcoal column (100 mm length × 5 mm diameter) was pumped through the cup, and volatiles were forced into a glass trap (120 mm length × 8 mm diameter) containing 50 mg Porapak Q (80/100 mesh, Supelco, Bellefonte, PA, USA). All of the connections were made with Teflon tape. The collection of volatiles was conducted over 6 h from 09:00 to 15:00. Then, the glass traps were eluted twice with a total of 300 μL of HPLC grade hexane (Sigma-Aldrich, Oakville, ON, Canada), and the volatile compounds were stored in sample vials (2 mL; Agilent Technologies, California, USA) at −80 °C until use.

Contech Enterprises (Delta, BC, Canada) provided (±)-exo-brevicomin and (±)-frontalin. Bedoukian Research (Danbury, CT, USA) provided (–)-trans-verbenol. Finally, (1S)-(–)-verbenone, HPLC-grade hexane, 1-hexanol, and methanol, as well as 10 host volatiles of D. armandi were purchased from Sigma-Aldrich.

Filters (PTFE, 13 mm, 0.22 µm) were obtained from Phase Separations, Australia. Anhydrous sodium sulphate powder, HPLC grade dichloromethane, and HPLC grade hexane were obtained from Sigma-Aldrich, Australia. The analytical standards used in this study were prepared from the following solutions: a custom semi-volatile organic compound mix (PM Separations, Australia), a polyaromatic hydrocarbon (PAH) organic compound mix (Trajan Scientific, Australia), a ‘single column analytes’ mix (Novachem, Australia), and an 8270 phenols standard (Phenomenex, Australia). Phenol-d6, phenanthrene-d10, 1,4-dichlorobenzene-d4, acenaphthene-d10, p-terphenyl-d14, and chrysene-d12 were used as internal standards and were obtained from Sigma-Aldrich, Australia.

The concentrations of chloroorganic pesticides and their metabolites, namely, α-HCH, β-HCH, γ-HCH, p,p′-DDE, p,p′-DDD, o,p′-DDE, o,p′-DDD, heptachlor, cis-chlordane, trans-chlordane, cis-nonachlor, trans-nonachlor, aldrin, mirex, hexachlorobenzene, 1,2,3,5-tetrachlorobenzene, and 1,2,4,5-tetrachlorobenzene, and the polychlorinated biphenyls (PCBs) 28, 52, 101, 105, 118, 123, 128, 138, 153, 180, and 183, were measured in serum.
HPLC-grade hexane and all high-purity analyte standards were obtained from Sigma-Aldrich (Steinheim, Germany). Labeled ¹³C₁₂ PCB101 was obtained from Cambridge Isotope Laboratories (Tewksbury, MA. USA) and 2,4,5,6-tetrachloro-m-xylene, 4,4′-dibromooctafluorobiphenyl, and 2,3,5,6-Tetrabromo-p-xylene (TBX) were obtained from Sigma-Aldrich (Steinheim, Germany). Sulfuric acid (98% purity) was purchased from Supelco (Bellefonte, PA. USA). Helium (99.9999% purity) and nitrogen (99.9999% purity) were obtained from NIIKM (Moscow, Russia).