REAKTIVE GELB F 97494

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 June 12, 2002 to June 12, 2002

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

Radiolabelling:

no

Test temperature:

20°C

Details on study design: HPLC method:

REAGENTS
- Methanol, Chromasolv Riedel de Haen
- Distilled water, Roth
- Potassium phosphate monobasic, Fluka (KH2PO4)
- Sodium hydroxide (c = 1 mole/L), Riedel de Haen
- Hydrochloric acid (c = 1 mole/L), Merck
- Buffer pH: 8 (136.1 g KH2PO4 dissolved in distilled water and filled up to a volume of 1000 mL. 50 mL of this solution and 30 mL sodium hydroxide solution (c = 1 mole/L) diluted with distilled water and filled up to a volume of 1000 mL with distilled water, the pH value was adjusted to 8.0.)
- Dead time marker: Uracil, Riedel de Haen
- Calibration substances (Merck, Aldrich, Riedel de Haen): Benzamide, Acetanilide, Aniline, Monuron, 3,5-dinitrobenzamide, Triadimenol, Linuron, Terbutryn, Naphthalene, Direct Red 81

CHROMATOGRAPHIC CONDITIONS
The chromatographic conditions were the same for the determination of ‘dead time’, the establishment of the calibration graph and the measurement of the test substance.

HPLC EQUIPMENT
- HPLC pump G1311A, autosampler G1313A, column oven G1316A and UV/VIS detector G1314A by Agilent

COLUMN
- Material: stainless steel, dimensions: 125 mm x 4.6 mm by Duratec (18904-02)
- Stationary phase: LiChrospher 100 CN 5 µm
- Column temperature: 20°C

MOBILE PHASE
- Methanole/buffer pH 8.0, 25 : 75 (v/v), isocratic elution
- Flow rate: 1.0 mVmin

INJECTION VOLUME:
- Dead time marker: 10 µL
- Test substance: 25 µL
- Calibration substances (without Direct Red): 10 µL
- Direct Red and test substance: 100 µL

INJECTION AMOUNTS
- Dead time marker: 2.72 ug
- Calibration substances: 0.71 - 7.42 µg
- Test substance: 3.91 µg
- The dead time marker was injected twice as solutions in acetonitrile/distilled water (50:50)
(vlv). The calibration substances (without Direct Red) were dissolved in acetonitrile and diluted 0.1 to 1 in the mobile phase and injected as single standards twice. Direct Red and the test substance were dissolved in distilled water and diluted 0.1 to 1 in buffer pH 8 and injected as single solutions twice.

DETECTION WAVELENGTH
- Dead time marker: 220 nm
- Calibration substances (without Direct Red): 220 nm
- Direct Red: 395 nm
- Test substance: 290 nm

Analytical monitoring:

not specified

Type:

log Koc

Value:

-0.24

Temp.:

20 °C

Remarks on result:

other: 0.12 (standard deviation)

Details on results (HPLC method):

Dead Time = 1.80 min
Log Koc of the test substance = -0.24

Table 1: Determination of the Dead Time (t₀)

Dead time marker	tRin min Measurement 1	tRin min Measurement 2	tRin min Mean
Uracil	1.80	1.80	1.80

 

Table 2:Calibration Data- 1. Measurement

(* from OECD guideline 121, adopted January 2001.)

Calibration substance	1. lnj. tRin min	k	Log k	Log Koc*
Benzamide	2.98	0.66	-0.18	1.00
Acetanilide	3.85	1.14	0.06	1.25
Aniline	3.29*^2	0.83	-0.08	2.07
Monuron	6.92	2.85	0.45	2.21
3,5-Dinitrobenzamide	3.83*^2	1.13	0.05	2.31
Triadimenol	17.99	9.01	0.95	2.40
Linuron	21.08	10.72	1.03	2.59
Terbutryn	22.05	11.26	1.05	2.68
Naphthalene	22.71	11.63	1.07	2.75
Direct Red 81	26.77	13.89	1.14	3.43

²not used for calculation

 

Regression: log Koc =a +b ×log k

Parameters:

 a =1.26

b = 1.47

r²=0.8996

 

 

Table 3: Log Koc of the Test Substance – 1. Measurement

Calibration substance	1. lnj. tRin min	k	Log k	Log Koc
Reaktiv Gelb F-97494	1.99	0.11	-0.96	-0.16

 

 

Table 4:Calibration Data- 2. Measurement

* from OECD guideline 121, adopted January 2001.

Calibration substance	1. lnj. tRin min	k	Log k	Log Koc*
Benzamide	2.94	0.64	-0.20	1.00
Acetanilide	3.77	1.10	0.04	1.25
Aniline	3.20*^2	0.78	-0.11	2.07
Monuron	6.69	2.72	0.43	2.21
3,5-Dinitrobenzamide	3.70*^2	1.06	0.02	2.31
Triadimenol	17.29	8.61	0.94	2.40
Linuron	20.32	10.30	1.01	2.59
Terbutryn	21.27	10.83	1.03	2.68
Naphthalene	21.93	11.19	1.05	2.75
Direct Red 81	24.26	12.49	1.10	3.43

²not used for calculation

 

Regression: log Koc =a +b ×log k

Parameters:

  a =1.29

b = 1.47

r²=0.8900

 

 

Table 5: Log Koc of the Test Substance – 2. Measurement

Calibration substance	1. lnj. tRin min	k	Log k	Log Koc
Reaktiv Gelb F-97494	1.94	0.08	-1.10	-0.32

 

 

Table 6:Log Koc of the Test Substance

	log Koc
1.    Measurement	-0.16
2.    Measurement	-0.32
Mean	-0.24
Standard deviation	0.12
RSD%	50

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the study, the adsorption coefficient (log Koc) of the test substance was determined to be -0.24.

Executive summary:

A study was conducted to determine the adsorption coefficient of the test substance according to the "HPLC method" described in the 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) and methanole/buffer pH 8.0 (25:75 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 290 nm.

Under the conditions of the study, the adsorption coefficient (log Koc) of the test substance was determined to be -0.24.

Description of key information

Under the conditions of the study, the adsorption coefficient (log Koc) of the test substance was determined to be -0.24.

Key value for chemical safety assessment

Koc at 20 °C:

0.575

Additional information

A study was conducted to determine the adsorption coefficient of the test substance according to the "HPLC method" described in the EU Method C.19 and OECD Guideline 121, in compliance with GLP. The test substance was injected twice into an HPLC column wherethe stationary phase was composed of LiChrospher 100 CN (5 µm) and methanole/buffer pH 8.0 (25:75 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 290 nm. Under the conditions of the study, the adsorption coefficient (log Koc) of the test substance was determined to be -0.24.