1-[2-(2-chloroethoxy)phenylsulfonyl]-3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)urea;triasulfuron (ISO)

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 Nov 1993 to 14 Jan 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Version / remarks:

May 1981

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Version / remarks:

Dec 1992

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

1.6

Temp.:

25 °C

pH:

5

Key result

Type:

log Pow

Partition coefficient:

1.7

Temp.:

25 °C

pH:

6.9

Type:

log Pow

Partition coefficient:

2.6

Temp.:

25 °C

pH:

9

Details on results:

The reported values indicate the concentrations of the neutral test substance. The uncorrected Log Pow values measured at 25 °C are: 1.1, -0.59 and -1.8 for pH at 5.0, 6.9 and 9.0, respectively.

The variation between the corrected log P values indicates that the assumption that the test substance exists in octanol (saturated with the respective buffer) solely as the neutral species is not entirely justified. At pH 9.00, a significant proportion of the test substance exists in the charged form as either the potassium or the sodium salt. Even at pH 7.00 some of the test substance in the octanol must exist as a salt. However, this proportion is less than that in the pH 9.00 system, therefore the corrected log P value using the buffer pH 7.00 is nearer to that using buffer pH 5.00.

1.Experimental Data and Results (uncorrected P and log P values)

sample number	P1	P2		P3		P4		P5	P6
amount of test substance/ mg	14.9250	15.2235		16.1190		16.1190		13.7310	14.0295
volume of octanol / mL	20.0	20.0		40.0		40.0		10.0	10.0
volume of buffer / mL	25.0	25.0		25.0		25.0		25.0	25.0
concentration of the  substance in the octanol phase / (mg/L)	134.430	131.316		117.849		120.748		128.959	127.409
	132.978	131.483		117.753		119.709		128.741	127.355
average of 2 values	133.704	131.400		117.801		120.229		128.850	127.382
concentration of the substance in the aqueous phase/ (mg/L)	515.795	501.407		456.373		462.452		508.459	490.941
	516.927	501.040		456.013		462.851		506.297	491.825
average of 2 values	516.361	501.224		456.193		462.652		507.378	491.383
pH of aqueous phase	6.84	6.90		6.91		6.96		6.93	6.93
amount of substance in the octanol phase / mg	2.6741	2.6280		4.7120		4.8092		1.2885	1.2738
amount of substance in the aqueous phase / mg	12.9090	12.5306		11.4048		11.5663		12.6845	12.2846
total recovered amount of substance / mg	15.5831	15.1586		16.1168		16.3755		13.9730	13.5584
recovery/%	104	100		100		102		102	97
Pow	0.2589	0.2622		0.2582		0.2599		0.2540	0.2592
average Pow	0.2606			0.2591				0.2566
average Pow ± S. D.	0.2587 ± (0.0027)
log Pow	-0.5869		-0.5814		-0.5880	-0.5852	-0.5952		-0.5864
average log Pow	-0.5842				-0.5866		-0.5908
average log Pow± S. D.	-0.5872 ± (0.0045)

sample number	P51	P52		P53	P54		P55	P56
amount of test substance / mg 1	1.0946	1.0946		2.1891	2.1891		0.5473	0.5473
volume of octanol / mL 2	20.0	20.0		40.0	40.0		10.0	10.0
volume of buffer/ mL	25.0	25.0		25.0	25.0		25.0	25.0
concentration of the substance in the octanol phase / ( mg/L )	50.706	55.147		48.985	50.585..		42.595	42.699
	46.123	48.527		49.731	51.028		42.273	42.295
	46.503	48.441		49.228	51.294		42.188	41.907
average of 3 values	47.777	50.705		49.315	50.969		42.352	42.300
concentration of the substance in the aqueous phase / (mg/L)	3.972	3.997		4.342	4.311		3.539	3.574
	3.978	3.998		4.332	4.309		3.531	3.581
	3.991	3.982		4.348	4.325		3.532	3.595
average of 3 values	3.980	3.992		4.341	4.315		3.534	3.583
pH of aqueous phase	5.04	5.05		5.08	5.06		5.02	5.02
amount of substance in the octanol phase / mg	0.9555	1.0141		1.9726	2.0388		0.4235	0.4230
amount of substance in the aqueous phase / mg	0.0995	0.0998		0.1085	0.1079		0.0884	0.0896
total recovered amount of substance / mg	1.0550	1.1139		2.0811	2.1467		0.5119	0.5126
recovery/%	96	102		95	98		94	94
Pow	12.004	12.702		11.360	11.812		11.984	11.806
average Pow	12.353			11.586			11.895
average Pow ± S. D.				11.9 ± (0.438)
log Pow	1.0793		1.1039	1.0554		1.0723	1.0786		1.0721
average log Pow	1.0916			1.0639			1.0754
average log Pow ± S. D.	1.077 ± (0.016)

sample number	P91	P92	P93	P94	P95	P96
amount of test substance / mg	49.3520	49.8495	50.8445	49.8495	50.6455	49.9490
volume of octanol / mL volume of buffer / mL	20.0 25.0	20.0 25.0	40.0 25.0	40.0 25.0	10.0 25.0	10.0 25.0
concentration of the substance in the octanol phase/ (mg/L)	32.154 32.331 32.258	33.216 33.315 33.273	33.831 33.684 33.738	32.855 32.826 32.969	32.068 31.969 32.017	32.761 33.000 32.918
average of 3 values	32.248	33.268	33.751	32.883	32.018	32.893
concentration of the substance in the aqueous phase / (mg/L)	1972.500 1978.926	1991.623 1997.077	2011.519 2012.050	1962.15 1964.12c	2029.476 2036.302	2018.493 2020.569
average of 2 values	1975.713	1994.350	2011.785	1963.14	2032.889	2019.531
pH of aqueous phase	9.02	8.97	8.99	9.00	8.96	8.95
amount of substance in the octanol phase / mg	0.6450	0.6654	1.3500	1.3153	0.3202	0.3289
amount of substance in the aqueous phase / mg	49.3928	49.8588	50.2946	49.0785	50.8222	50.4883
total recovered amount of substance / mg	50.0378	50.5242	51.6446	50.3938	51.1424	50.8172
recovery/%	101	101	102	101	101	102
Pow	0.01632	0.01668	0.01678	0.01675	0.01575	0.01629
average Pow	0.01650		0.01677		0.01602
average Pow ± S. D.	0.01643 ± (0.00040 )
log Pow	-1.7873	-1.7778	-1.7752	-1.7760	-1.8027	-1.7881
average log Pow	-1.7826		-1.7756		-1.7954
average log Pow± S. D.	-1.7845 ± (0.0105)

Conclusions:

The octanol-water partition coefficient (Log Pow) of the test substance at 25 °C was found to be 1.6, 1.7 and 2.6 at pH 5.0, 6.9 and 9.0, respectively.

Executive summary:

The octanol-water partition coefficient (Log Pow) of the test substance was determined using the shake-flask method and according to OECD TG 117 following GLP principles. At 25 °C the partition coefficient (n-octanol / water) of the test substance was found to be 1.6, 1.7 and 2.6 at pH 5.0, 6.9 and 9.0, respectively.

Description of key information

Log Pow: 1.6, 1.7 and 2.6 at pH 5.0, 6.9 and 9.0, respectively at 25°C, OECD TG 107, shake-flask method, Stulz 1994

Key value for chemical safety assessment

Log Kow (Log Pow):

1.7

at the temperature of:

25 °C