Atrazine

Cyromazine (98.5%), bispyribac sodium, diquate dibromide, melamine, acetamipride, dinotefuran, imidachloprid, flucarbazone, and atrazine were purchased from Dr. Ehrenstorfer GmbH (Stuttgart, Germany). Polyaniline (emeraldine salt) (Average M_w > 15,000, 3–100 μm particle size), methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), benzoyl peroxide (BPO), potassium tetrakis (3,5-bis (trifluoromethyl) phenyl) borate (KTFPB), and acetonitrile were purchased from Sigma-Aldrich Inc. (St. Louis, MO, USA). High molecular weight poly(vinyl chloride) (PVC), sodium tetraphenyl borate (NaTPB), dioctyl phthalate (DOP), and tetrahydrofuran (THF) were obtained from Fluka AG (Buchs, Switzerland). Tetrahydrofuran (THF) was freshly distilled prior to use. For pesticide technical formulation, a nominee-kz, 3% soluble liquid (SL) of Cyromazine, was purchased from Kafr El-Zayat Pesticides and Chemicals Company (Gharbia, Egypt). All other chemical reagents were of analytical grade and used without any further purification. A stock Cyromazine solution (10⁻² M) was prepared by dissolving 0.166 g pure Cyromazine in 100 mL distilled water and the pH of the solution was adjusted to pH 3.5 using 0.1 M acetic acid. Dilutions of CYR (10⁻³–10⁻⁷ M) were prepared in 50 mM acetate solution, pH 3.5.

Dow Corning OFX 0309 was purchased from Ingredients Plus, Malaysia. Atrazine (molecular weight: 215.68 g mol⁻¹, λ_max: 222 nm) and propazine (molecular weight: 229.71 g mol⁻¹, λ_max: 222 nm) were purchased from Dr Ehrenstorfer, Germany (99% purity). Standard stock solutions of Atrazine (1000 mg l⁻¹) and propazine (1000 mg l⁻¹) were prepared in methanol. The working solutions were freshly prepared daily by an appropriate dilution of the stock solutions in deionized water. For all experiments, OFX 0309 surfactant and both triazine species were used without further purification. Hydrochloric acid (HCl) and sodium hydroxide (NaOH) were used for pH adjustment. Potassium carbonate (K₂CO₃), sodium carbonate (Na₂CO₃), potassium hydroxide (KOH), potassium chloride (KCl), sodium chloride (NaCl), sodium nitrate (Na₂NO₃) and sodium sulfate (Na₂SO₄) (purchased from QRec, Malaysia) were prepared by dissolving an appropriate amount in deionized water. Trichloroacetic acid (TCA), purchased from Fisher Chemical, USA, was used in the deproteination of milk samples.

The following chemicals were used for exposure studies: atrazine (CAS 1912-24-9), 99.3% purity, Dr. Ehrenstorfer GmbH, Augsburg, Germany; deltamethrin (CAS 52918-63-5), 99.5% purity, Dr. Ehrenstorfer GmbH, Augsburg, Germany; diazinon (333-41-5), 99% purity, Dr. Ehrenstorfer GmbH, Augsburg, Germany; Dimethyl sulfoxide (CAS 67-68-5), 99.9% purity, Sigma-Aldrich, St. Louis, USA; diuron (CAS 330-54-1), 98.8% purity, Dr. Ehrenstorfer GmbH, Augsburg, Germany; hydrogen peroxide (H₂O₂) (CAS 7722-84-1), Sigma-Aldrich, Steinheim, Germany; metazachlor (CAS 67129-08-2), 99.5% purity, Dr. Ehrenstorfer GmbH, Augsburg, Germany; sulforaphane (SFN) (CAS 4478-93-7), 90% purity, Sigma-Aldrich, Steinheim, Germany; terbutylazine (tBA) (CAS 5915-41-3), 99.5% purity, Dr. Ehrenstorfer GmbH, Augsburg, Germany; tertbutylhydroquinone (tBHQ) (CAS 1948-33-0), 97% purity, Sigma-Aldrich, St. Louis, USA.
The compounds were dissolved in 20 mM stock solutions of atrazine, deltamethrin, diazinon, diuron, metazachlor, and terbutylazine in 99% EtOH and stored at −20 °C. Stock solutions of H₂O₂ and tBHQ of 100 mM were prepared in 99% EtOH and stored at −20 °C for every new experiment. A 50 mM stock of SFN in 99% EtOH was prepared and stored at −80 °C.