imidacloprid (ISO); 1-(6-chloropyridin-3-ylmethyl)-N-nitroimidazolidin-2-ylidenamine

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17-21 Sep 2015

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)

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7550 (Partition Coefficient, n-octanol / H2O, Shake Flask Method)

GLP compliance:

yes (incl. QA statement)

Remarks:

Hess. Ministerium fur Umwelt, ländlichen Raum und Verbraucherschutz, Wiesbaden, Germany

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

0.6

Temp.:

24 °C

pH:

4

Type:

log Pow

Partition coefficient:

0.7

Temp.:

24 °C

pH:

7

Type:

log Pow

Partition coefficient:

0.6

Temp.:

24 °C

pH:

9

Individual results pH 4:

Experiment:	1A	1B	2A	2B	3A	3B
Phase ratio 1-octanol : aqueous phase	1 : 2	1 : 2	1 : 1	1 : 1	2 : 1	2 : 1
Volume of the 1-octanol phase [mL]	5	5	10	10	20	20
Volume of the aqueous phase [mL]	10	10	10	10	10	10
Concentration in the 1-octanol phase [mg/L]*	1485.3	1478.5	884.5	881.0	488.2	490.9
Concentration in the aqueous phase [mg/L]*	350.9	356.5	211.6	210.2	120.9	117.9
Mass balance [mg]	10.936	10.958	10.961	10.912	10.973	10.997
Mass balance [%]	100	101	101	100	101	101
pH of the aqueous phase	4.02	4.02	4.02	4.02	4.02	4.02

*rounded values

Partition coefficients at pH 4:

Exp.	Pow*	Average Pow	SD	RSD [%]	Log Pow
1A 1B	4.23 4.15	4.19	0.06	1.4	0.62
2A 2B	4.18 4.19	4.19	0.01	0.2	0.62
3A 3B	4.04 4.16	4.10	0.09	2.2	0.61
Average Pow		Pow*=4.2	0.05	1.2

* rounded values

Individual results pH 7:

Experiment:	1A	1B	2A	2B	3A	3B
Phase ratio 1-octanol : aqueous phase	1 : 2	1 : 2	1 : 1	1 : 1	2 : 1	2 : 1
Volume of the 1-octanol phase [mL]	5	5	10	10	20	20
Volume of the aqueous phase [mL]	10	10	10	10	10	10
Concentration in the 1-octanol phase [mg/L]*	1603.7	1592.6	923.3	932.3	471.2	517.7
Concentration in the aqueous phase [mg/L]*	346.3	344.5	206.1	205.7	114.4	114.5
Mass balance [mg]	11.482	11.408	11.294	11.380	10.568	11.499
Mass balance [%]	103	102	101	102	95	103
pH of the aqueous phase	7.02	7.01	7.01	7.00	7.00	7.00

* rounded values

Partition coefficients at pH 7:

Exp.	Pow*	Average Pow	SD	RSD [%]	Log Pow
1A 1B	4.63 4.62	4.63	0.01	0.1	0.67
2A 2B	4.48 4.53	4.51	0.04	0.8	0.65
3A 3B	4.12 4.52	4.32	0.28	6.6	0.64
Average Pow		Pow* = 4.5	0.15	0.34

* rounded values

Individual results pH 9:

Experiment:	1A	1B	2A	2B	3A	3B
Phase ratio 1-octanol : aqueous phase	1 : 2	1 : 2	1 : 1	1 : 1	2 : 1	2 : 1
Volume of the 1-octanol phase [mL]	5	5	10	10	20	20
Volume of the aqueous phase [mL]	10	10	10	10	10	10
Concentration in the 1-octanol phase [mg/L]*	1506.5	1501.3	891.2	883.8	491.8	484.2
Concentration in the aqueous phase [mg/L]*	352.6	345.3	207.8	208.3	115.6	115.6
Mass balance [mg]	11.059	10.960	10.990	10.921	10.992	10.840
Mass balance [%]	101	100	100	100	100	99
pH of the aqueous phase	9.00	9.01	9.02	9.02	9.04	9.04

* rounded values

Partition coefficients at pH 9:

Exp.	Pow*	Average Pow	SD	RSD [%]	Log Pow
1A 1B	4.27 4.35	4.31	0.05	1.2	0.63
2A 2B	4.29 4.24	4.27	0.03	0.8	0.63
3A 3B	4.25 4.19	4.22	0.05	1.1	0.63
Average Pow		Pow* = 4.3	0.04	1.0

* rounded values

Reference 2

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

supporting study

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)

GLP compliance:

yes

Remarks:

study conducted not formally, but essentially in compliance with GLP standards

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

0.57

Temp.:

21 °C

pH not reported. Log Pow corresponds to Pow value of 3.70.

Description of key information

log Pow at 24 °C: 0.7 at pH 7; 0.6 at pH 4 and pH 9 (OECD 107, EU A.8, flask method)

Key value for chemical safety assessment

Log Kow (Log Pow):

0.7

at the temperature of:

24 °C

Additional information

In an earlier determination according to OECD 107 (flask method), a log Pow value of 0.57 was obtained at 21 °C, pH not reported. This study is supporting.