1 3 dichlorobenzene

Chlordecone was obtained from Azur Isotopes (purity 98%). Chemical products used for microbiological media, vitamin B₁₂ (>98%), chloro(pyridine)cobaloxime(III), lindane (97%), 1,3-dichlorobenzene (98%), 1,4-dichlorobenzene (99%), chlorobenzene (99.8%), and benzene (99.8%) were obtained from Sigma Aldrich. Titanium (III) citrate was prepared from titanium (III) chloride (>12% in HCl; Sigma Aldrich) and sodium citrate and neutralized with Na₂CO₃ (Chevallier et al., 2019 (link)). Dichloromethane (HPLC grade) was obtained from Fisher Chemical.

Headspace-solid phase microextraction (HS-SPME) was the extraction method used to determine the aroma profile of the three dry dog food diets manufactured with red sorghum and the control diet. The samples were ground and then 0.5 g was weighed and placed in a 10 mL screw-cap vial (Supelco Analytical, Bellefonte, PA, USA) equipped with a polytetrafluoroethylene/silicone septum (Supelco Analytical, Bellefonte, PA, USA). Successively, 0.99 mL of distilled water was added to the ground sample in the vial. A similar approach was utilized by Koppel et al. [11 (link)]. The internal standard utilized was 0.01 mL of 1,3-dichlorobenzene dissolved in methanol (Sigma Aldrich, St. Louis, MO, USA) with a final concentration in the sample of 20 μg/kg. Vials were equilibrated in an autosampler (Pal system, model CombiPal, CTC Analytics, Zwingen, Switzerland) for 10 min at 40 °C and then agitated at 250 rpm. Following equilibration, a 50/30 μm divinylbenzene/carboxen/dimethyl-siloxilane fiber (Supelco Analytical, Bellefonte, PA, USA) was utilized. The fiber was exposed to the sample headspace for 30 min at 40 °C. After sampling, the analytes were desorbed from the SPME fiber coating to the injection port of gas chromatography (GC) at 270 °C for 3 min in splitless mode.

1,3-dichlorobenzene (98%) was purchased from Aldrich (Steinheim, Germany). The metabolites 3,5-dichlorocatechol (97%), 3,5-dichlorophenol (Pestanal grade) and 2,4-dichlorophenol (Pestanal grade) were also purchased from Aldrich (Steinheim, Germany). The isotope labelled internal standards D₃-3,5-dichlorophenol (98,5% D₃) and D₃-2,4-dichlorophenol (98,5% D₃) were provided from CDN Isotopes (Pointe Claire, Quebec, Canada). D₃-2,4-dichlorobenzoic acid (98,5% D₃) was used as internal standard for the quantification of 3,5-dichlorocatechol and was also purchased from CDN Isotopes (Pointe Claire, Quebec, Canada).
Formic acid (100%) and water (LC/MS grade) was supplied by Merck (Darmstadt, Germany). Acetonitrile (HPLC grade) was purchased from J.T. Baker (Germany). Ammonium formate was supplied by Fluka (Buchs, Suisse).