Hexabromocyclododecane

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 September 2010 to 23 September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Test guideline 1

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

Test guideline 2

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

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Test material

Test material information

Constituent 1

Reference substance name:

Hexabromocyclododecane

EC Number:

247-148-4

EC Name:

Hexabromocyclododecane

Cas Number:

25637-99-4

Molecular formula:

C12H18Br6

IUPAC Name:

(1S,2S,5S,6S,9S,10S)-1,2,5,6,9,10-hexabromocyclododecane

Details on test material:

Name: Great Lakes CD-75P
Lot No.: 609062G1
CAS No.: 25637-99-4
Chemical name: Hexabromocyclododecane
Purity: 99.0 %
Appearance: White to off-white powder
Production date: 03 March 2009
Expiry date: 02 March 2014
Storage: room temperature 15-25ºC, continuously protected from all light
Manufacturer: Great Lakes Chemical Corporation

Radiolabelling:

no

Study design

Test temperature:

22ºC

HPLC method

Details on study design: HPLC method:

EQUIPMENT
Stationary Phase
LiChrospher 100 CN 250 × 4 mm, 5µm HPLC Column No.: 540779-1

HPLC system: Surveyor HPLC system:
Pump, No. : 54075
Autosampler, No.: 55097
PDA Detector, No.: 56138
655A-52 Column Oven, No.: 6211-016
Ultrasonic bath: Elmasonic S300H, ELMA, No.: 010890105

Balance: BP221S Sartorius, No.: 11809117

Water purification system: MILLIPORE, DIRECT Q3, FOMNO 7334I

HPLC Conditions:
Detector: UV at 210 nm
Column: LiChrospher 100 CN 250 x 4 mm, 5µm No.: 540779-1
Mobil Phase: Acetonitrile : water = 1 : 1
Flow: 1 ml/min.
Injection volume: 10 µl
Temperature: 22 °C

REFERENCE SUBSTANCES
Nine chemicals for which log Koc has been reported were used to calibrate the elution time in units of log Koc.

Dead time, t0 was determined by the injection of sodium nitrate solution.

Table 1. Reference substances used for calibration
Chemical name CAS Number log Koc Purity, Supplier Batch No.
Sodium nitrate 7631-99-4 t0 100 % Merck KGaA A980637
Acetanilide 103-84-4 1.25 99.9 % Merck KGaA S4715244
Methyl
benzoate 93-58-3 1.80 99.9 % Merck KGaA S4748230
Atrazine 1912-24-9 1.81 97.5 % Sigma-Aldrich 8087X
Isoproturon 34123-59-6 1.86 99.9 %, Sigma Aldrich SZE8200X
Triazophos 24017-47-8 2.55 66.5 % Sigma-Aldrich SZE8114X
Naphthalene 91-20-3 2.75 99.9 % Merck KGaA S4767446
Fenthion 55-38-9 3.31 97.8 %, Sigma Aldrich 6193X
α-Endosulfan 959-98-8 4.09 99.6 % Sigma-Aldrich SZE8289X
DDT 50-29-3 5.63 99.1 % Sigma-Aldrich 5143X


PREPARATION OF THE TEST SOLUTIONS
Reference substances and test item were dissolved in acetonitrile. Concentration of reference substances stock solutions was about 1 mg/ml, and the test item stock solution was about 200 µg/ml. These stock solutions were diluted with the mobile phase resulting in about 10 ºg/ml solutions except sodium nitrate (100 µg/ml), DDT (100 µg/ml), α-Endosulfan (1 mg/ml) and test item (200 µg/ml).

DETERMINATION OF RETENTION TIMES
Three series of the above reference solutions and the test item solution were measured alternately, with two replicate injections. For the determination of t0 (t0 = retention time of the unretarded component) sodium nitrate solution was injected. The retention times were determined.

EVALUATION
The capacity factors, k’ were calculated from the retention times (tR) of the selected reference substances and the dead time (t0):

K1=((tR-t0) / t0)

A calibration plot of log k' versus log Koc was prepared. (See Figure 1.) The calibration equation was determined by linear regression using the least squares method. Repeatability is the difference of maximum and minimum values of log Koc derived from individual measurements. Accuracy is the difference between the estimated log Koc and the log Koc value determined by the batch equilibrium method.

Results and discussion

Adsorption coefficient

Type:

log Koc

Value:

> 5

Temp.:

22 °C

Remarks on result:

other: The result shows that log Koc of Great Lakes CD-75P is significantly higher than the calibrated range. Therefore no accurate value of log Koc can be estimated.

Results: HPLC method

Details on results (HPLC method):

The three calibration series and three test item series were measured alternately. The adsorption coefficient Koc was determined based on a calibration curve using 8 reference items.

The capacity factors k’ were calculated from the dead time and retention times of the reference substances. The log k’ data of the reference substances were plotted against their log Koc values. The resulting calibration curve and the respective data are given in Figure 1 and Table 1 (see 'details on study design' above, respectively. The equation of the curve fitted to the calibration points is as follows:

log k' = 0.1463 × log Koc + 0.045 (Rsq = 0.965)

Retention time of Great Lakes CD-75P (12.95 min) is significantly higher than that of the last eluting standard, DDT (9.46 min). This result shows that log Koc of Great Lakes CD-75P is significantly higher than the calibrated range. Therefore no accurate value of log Koc can be estimated.

Any other information on results incl. tables

Table 1: Measured and calculated data of the reference substances and test item

Chemical name	log Koc	Retention time (min)	log k'	log Koc		Accuracy		Repeatability
	from OECD 121		Calculated	Calculated		log unit		DlogKOC, log unit
Sodium nitrate	-	1.25	for determination of dead time
		1.25
		1.22
		1.22
		1.22
		1.22
	Mean	1.23
	CV%	1.3
Acetanilide	1.25	3.07	0.175	0.89		0.02		0.36
		3.07	0.175	0.89
		3.07	0.175	0.89
		3.07	0.175	0.89
		3.07	0.175	0.89
		3.08	0.177	0.9
	Mean	3.07	0.175	0.89
	CV%	0.1	-	-
Methyl-benzoate	1.8	3.73	0.308	1.8		0.01		0
		3.73	0.308	1.8
		3.73	0.308	1.8
		3.73	0.308	1.8
		3.74	0.31	1.81
		3.74	0.31	1.81
	Mean	3.73	0.309	1.8
	CV%	0.1	-	-
Atrazine	1.81	3.58	0.281	1.61		0.01		0.19
		3.58	0.281	1.61
		3.58	0.281	1.61
		3.58	0.281	1.61
		3.59	0.283	1.63
		3.59	0.283	1.63
	Mean	3.58	0.282	1.62
	CV%	0.1	-	-
Isoproturon	1.86	3.74	0.31	1.81		0		0.05
		3.74	0.31	1.81
		3.74	0.31	1.81
		3.74	0.31	1.81
		3.74	0.31	1.81
		3.74	0.31	1.81
	Mean	3.74	0.31	1.81
	CV%	0	-	-
Triazophos	2.55	5.01	0.488	3.03		0.01		0.48
		5.01	0.488	3.03
		5.02	0.489	3.03
		5.01	0.488	3.03
		5.01	0.488	3.03
		5.01	0.488	3.03
	Mean	5.01	0.488	3.03
	CV%	0.1	-	-
Naphthalene	2.75	4.84	0.468	2.89		0.01		0.14
		4.84	0.468	2.89
		4.83	0.466	2.88
		4.83	0.466	2.88
		4.84	0.468	2.89
		4.84	0.468	2.89
	Mean	4.84	0.467	2.89
	CV%	0.1	-	-
Fenthion	3.31	5.74	0.564	3.55		0.01		0.14
		5.73	0.563	3.54
		5.74	0.564.	3.55
		5.75	0.565	3.56
		5.74	0.564	3.55
		5.74	0.564	3.55
	Mean	5.74	0.564	3.55
	CV%	0.1	-	-
a-Endosulfan	4.09	6.71	0.649	4.13		0.03		0.04
		6.69	0.647	4.12
		6.74	0.651	4.14
		6.72	0.65	4.13
		6.72	0.65	4.13
		6.71	0.649	4.13
	Mean	6.72	0.649	4.13
	CV%	0.2	-	-
DDT	5.63	9.45	0.825	5.33		0.03		0.3
		9.46	0.825	5.34
		9.49	0.827	5.35
		9.5	0.828	5.35
		9.42	0.823	5.32
		9.42	0.823	5.32
	Mean	9.46	0.825	5.33
	CV%	0.4	-	-
Great Lakes CD-75P	-	12.95	-	-		-		-
		12.92	-	-
		13.02	-	-
		13.02	-	-
		12.88	-	-
		12.91	-	-
	Mean	12.95	-	-
	CV%	0.4	-	-

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Conclusions:

Under the conditions and range of the study the Log Koc was determined to be >5.0 at 22ºC.