13c12 dieldrin

Neat standards of p,p’-DDE (CAS# 72-55-9, 99% pure) and dieldrin (CAS# 60-57-1, 98.7% pure) were purchased from Aldrich (Milwaukee, WI). Neat standards of triclosan (TCS, CAS# 3380-34-5, 96% pure) and triclocarban (TCC, CAS# 101-20-2, 98% pure) were purchased from TCI America (Montgomeryville, PA), while fipronil (CAS# 120068-37-3, 98% pure) was obtained from Enzo Life Sciences (Farmingdale, NY). Isotope internal standards (¹³C₁₂-p,p’- DDE, ¹³C₁₂-dieldrin, ¹³C₁₂-TCS, and ¹³C₆-TCC) were purchased from Cambridge Isotope Laboratories (Tewksbury, MA), whereas ¹³C₂,¹⁵N₂-fipronil internal standard was purchased from Toronto Research Chemicals (TRC, Canada). Organic solvents (HPLC-grade hexane, acetone, and acetonitrile) were purchased from Fisher Scientific (Fair Lawn, NJ).

Neat standards of p, p’-DDE (CAS# 72-55-9, 99% pure) and dieldrin (CAS# 60-57-1, 98.7% pure) were purchased from Aldrich (Milwaukee, WI). A stock solution of 18 OCPs containing α-, β -, γ -, δ-hexachlorocyclohexane (HCH) isomers, α- and β- chlordane isomers, p, p’-DDD, p, p’-DDE, p, p’-DDT, dieldrin, aldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, heptachlor, heptachlor epoxide, and methoxychlor at a concentration of 2000 µg/ml in hexane:toluene (1:1 v/v) were purchased from Phenomenex (Torrance, CA). Isotope internal standards (¹³C₁₂-p, p’-DDE and ¹³C₁₂-dieldrin) and a mixture of deuterated internal standards (acenaphtlene-d10, chrysene-d12, and phenanthrene-d10) were obtained from Cambridge Isotope Laboratories (Tewksbury, MA) and Ultra Scientific (North Kingstown, RI), respectively. Organic solvents (hexane, acetone, and acetonitrile) were purchased from Fisher Scientific (Fair Lawn, NJ).