1 4 dichlorobenzene d4

Frozen cancerous and healthy breast tissues from different patients were purchased from the Israeli Biorepository Network for Research MIDGAM (Haifa, Israel). Both cancerous and noncancerous tissues from patients who had not undergone chemotherapy were collected after surgery. The frozen tissues were transported inside plastic cryovials in dried ice and kept at −80 °C pending the experiment. All tissue samples were thawed in their plastic cryovials to room temperature for 10–20 min and ≈40 mg samples were immersed (500 [µL]‐ tissue [mg]) µL in 0.9% NaCl in double‐distilled water. EPA 524 internal standard mix with 2000 µg mL⁻¹ 1,4‐dichlorobenzene‐d4 in methanol, purchased from Sigma‐Aldrich, was used as internal standard at 40 ppb. Tissue samples were analyzed by GC‐MS and the HSGC sensor set‐up.

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.