Octanol/water partition coefficients of toxaphene congeners determined by the “slow-stirring” method

The octanol/water partition coefficients (KOW) for a series of technical toxaphene peaks and congeners (n = 36) and organochlorines (pentachlorobenzene (PCIBz), hexachlorobenzene (HClBz), mirex and polychlorinated biphenyl congeners (CB) 105, 153 and 209) were determined using the “slow-stirring” technique with two different concentrations at 25°C. KOWS of the organochlorines were consistent with published values and results from the two treatments were in good agreement, suggesting the toxaphene congener KOWs are accurate and precise. Log KOW of toxaphene components / congeners ranged from 4.77 ± 0.076 to 6.64 ± 0.074, and were significantly related to chlorine number (log KOW = 3.4 + [0.28* # Cl], r2 = 0.44, p < 0.001). Additional variation in toxaphene congener KOW, and likely other physical chemical properties, is due to chlorine position and the structure of the carbon skeleton. These results represent some of the first physical-chemical properties of individual toxaphene congeners.