A comparison of log Kow (n-octanol–water partition coefficient) values for non-ionic, anionic, cationic and amphoteric surfactants determined using predictions and experimental methods

Environmental Sciences Europe

Table 3 CMC values at pH 7 for use as surrogate water solubility values for solubility ratio method calculations

Compound	#	CMC values (g/L)				Octanol solubility (mg/mL)^a
Compound	#	Using surface tension method [11]^a	Using SPME method [6]	Mean of literature values [6]	Mean and SD	Octanol solubility (mg/mL)^a
C8EO4	1	3.2	3.899 ± 0.506	3.839	3.65 ± 0.387	FSO
C12EO4	2	0.0343	0.018 ± 0.002	0.040	0.0308 ± 0.011	FSO
C12EO8	3	0.06	0.048 ± 0.008	0.038^b, 0.060 (0.049^c)	0.0523 ± 0.007	93.9
C12AS	4	1.15	3.701 ± 0.746	2.344	2.40 ± 1.28	0.9
C12E4S	5	0.405	0.281 ± 0.067	0.726	0.471 ± 0.230	79.2
C11COONa	6	1.97	0.238 ± 0.035	5.800	2.67 ± 2.85	77.9
C12TMAC	7	4.06	4.467 ± 0.405	4.222	4.25 ± 0.205	729.9
C16TMAC	8	0.08	0.125 ± 0.024	0.306	0.170 ± 0.120	359.3
C18BAC	9	0.11	0.0012 ± 0.0002	0.101	0.071 ± 0.060	118.6
C12–16ADB	10	0.26	ND	0.480^a	0.370 ± 0.156	19.6
C12ADB	10	ND	0.376 ± 0.116	0.451	0.414 ± 0.053	ND
C14ADB	10	ND	0.056 ± 0.010	ND	NA	ND
C16ADB	10	ND	0.0016 ± 0.0002	ND	NA	ND
C12AAPB	11	0.486	ND	0.318	0.402 ± 0.119	27.6
C12DAO	12	1.65	0.067 ± 0.015	0.480	0.732 ± 0.821	FSO
ATR	13	ND	0.039 ± 0.005^b	0.035^b	0.0370 ± 0.003	46
PCP	14	ND	0.658 ± 0.102^b	1.153^b	0.906 ± 0.350	7.4

FSO Test compounds is fully soluble in n-octanol and so not measurable, ND not determined, NA not applicable
^aAs reported by Fraunhofer IME in this study
^bBased on water solubility values, not the CMC
^cAverage of the two values