Pentasodium 2,2'-((2,4-diamino-5-(4-methoxy-2-sulfophenylazo)-1,3-phenylene)bis(azo))bis(5-(2-(sulfonatooxyethyl)sulfonyl)benzenesulfonate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From April 25, 2006 to April 26, 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

25°C

Details on study design: HPLC method:

- HPLC equipment: HPLC System Agilent 1100 series: HPLC pump G1311A, autosampler G1313A, column oven G1316A, degaser G1322A and UV/Vis detector G1314A by Agilent

- Column:
Stationary phase: LiChrospher 100 CN 5µm by Duratec (17405-02)
Material: stainless steel, dimensions: 250 mm x 4.6 mm
Column temperature: 25°C

- Mobile Phase: Methanol, cleaned water 50:50 % (v/v), isocratic elution
- Flow rate: 1.0 mL/minute
- Injection volume: 10 µL
- Detection wavelength: 210 nm for dead time marker, calibration substances and 420 nm for test substance
- Injection amounts/dilutions:
Dead time marker: 22.3 µg
Calibration substances: 0.68 - 1.79 µg
Test substance: 0.619 µg

- The dead time marker was dissolved in methanol and diluted 0.1 to 1 in the mobile phase and injected as single standards twice. The calibration substances were dissolved in methanol and diluted 0.1 to 1 in the mobile phase and injected as single standards twice. The test substance was dissolved in distilled water and diluted 0.1 to 1 with the mobile phase and injected as single sample twice.
- Reagents
Methanol, Chromasolv, Riedel de Haen
Cleaned water (laboratory equipment)
Distilled water, Roth
Dead time marker: Formamide, Merck
Calibration substances: Acetanilide, Atrazin, Monuron, Triadimenol, Linuron, Pyrazophos, Diclofop-methyl (Riedel de Haen)

Analytical monitoring:

not specified

Key result

Type:

log Koc

Value:

< 1.25

Temp.:

25 °C

Remarks on result:

other: log Koc of the test substance was below the log Koc of the lowest calibration substance (acetanilide)

Details on results (HPLC method):

- Dead Time (to) = 3.115 minutes
- Adsorption coefficient of the test substance (log Koc) <1.25

Transformation products:

not measured

Table 1: Determination of the Dead Time (t_o)

Dead time marker	tRin minutes Measurement - 1	tRin minutes Measurement - 2	tRin minutes Measurement - 3
Formamide	3.116	3.114	3.115

 Dead Time (t_o) = 3.115 minutes

 

Table 2: Calibration Data - Measurement 1

(*from OECD guideline 121, adopted January 2001)

Calibration substance	1. Injection tRin minutes	k	log k	Log Koc*
Acetanilide	4.014	0.29	-0.54	1.25
Atrazin	4.514	0.45	-0.35	1.81
Monuron	4.743	0.52	-0.28	1.99
Triadimenol	5.511	0.77	-0.11	2.40
Linuron	6.230	1.00	0.00	2.59
Pyrazophos	8.919	1.86	0.27	3.65
Diclofop-methyl	10.833	2.48	0.39	4.20

Regression:Log K_oc=a+bxlogk

Parameters:

a = 2.83

b = 3.07

r²= 0.9849

 

Table 3: Log K_ocof the test substance - Measurement 1

Test substance	1. Injection tRin minutes	k	log k	Log Koc
Reaktiv Braun F05-0209-05	1.186	-0.62	<-0.54	<1.25^#

^#Below log K_ocvalue of the lowest calibration substance (acetanilide).

 

Table4: Calibration Data - Measurement 2

(*from GECD guideline 121, adopted January 2001)

Calibration substance	1. Injection tRin minutes	k	log k	Log Koc*
Acetanilide	4.009	0.29	-0.54	1.25
Atrazin	4.510	0.45	-0.35	1.81
Monuron	4.742	0.52	-0.28	1.99
Triadimenol	5.514	0.77	-0.11	2.40
Linuron	6.229	1.00	0.00	2.59
Pyrazophos	8.917	1.86	0.27	3.65
Diclofop-methyl	10.825	2.48	0.39	4.20

Regression:Log K_oc=a+bxlogk

Parameters:

a = 2.83

b = 3.07

r²= 0.9849

 

Table5: Log K_ocof the test substance - Measurement 2

Test substance	2. Injection tRin minutes	k	log k	Log Koc
Reaktiv Braun F05-0209-05	1.183	-0.62	<-0.54	<1.25^#

^#Below log K_ocvalue of the lowest calibration substance (acetanilide).

 

Table6: Log Koc of the test substance

Measurements	log Koc
1. Measurement	<1.25
2. Measurement	<1.25
Mean	<1.25

 

The adsorption coefficient (LogK_oc) of the test substance was found to be <1.25

 

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the study, the adsorption coefficient (i.e., log Koc) of the test substance was determined to be <1.25. The substance has expectedly no adsorptive properties in soil.

Executive summary:

A study was conducted to determine the adsorption coefficient of the test substance according to the "HPLC method" described in EU Method C.19 and OECD Guideline 121, in compliance with GLP.

The test substance was injected twice into an HPLC column where the stationary phase was composed of LiChrospher 100 CN (5 µm). Methanol/cleaned water (50:50 v/v) was used as the mobile phase. A calibration graph was drawn by measuring the retention times of a series of substances with known adsorption coefficients. The adsorption coefficient of the test substance was derived by comparing its retention time with the calibration curve. Detection of the test substance was carried out at 420 nm.

 

Under the conditions of the study, the adsorption coefficient (i.e., log K_oc) of the test substance was determined to be <1.25

Description of key information

The adsorption coefficient (i.e., log Koc) of the test substance was determined to be <1.25.

Key value for chemical safety assessment

Koc at 20 °C:

17.8

Additional information

A study was conducted to determine the adsorption coefficient of the test substance according to the "HPLC method" described in EU Method C.19 and OECD Guideline 121, in compliance with GLP. The test substance was injected twice into an HPLC column where the stationary phase was composed of LiChrospher 100 CN (5 µm). Methanol/cleaned water (50:50 v/v) was used as the mobile phase. A calibration graph was drawn by measuring the retention times of a series of substances with known adsorption coefficients. The adsorption coefficient of the test substance was derived by comparing its retention time with the calibration curve. Detection of the test substance was carried out at 420 nm. Under the test conditions, the adsorption coefficient (i.e., log K_oc) of the test substance was determined to be <1.25 (Moller, 2006b).

[LogKoc: 1.25]