Non-graphitic carbon fibre

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019-11-26 to 2019-12-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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:

yes

Remarks:

A reduced number of reference items was used

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:

yes

Remarks:

A reduced number of reference items was used

GLP compliance:

yes

Type of method:

HPLC estimation method

Radiolabelling:

no

Details on study design: HPLC method:

Test System: Analytical HPLC-column packed with a cyanopropyl stationary phase and coupled to a diode array detector (DAD)

HPLC-DAD-System HPLC AGILENT 1100 consisting of:

Auto sampler G1329A
Auto sampler thermostat G1330B
Pump G1312A
Degasser G1322A
Column oven G1316A
Detector G1315B

Software OpenLab 2.2, AGILENT TECHNOLOGIES

HPLC Column YMC-Pack CN, S 5 µm, 12 nm, 250 x 4.0 mm, batch 11761, YMC EUROPE GMBH

Injection volume 20 µL
Flow rate 1.0 mL/min
Mobile phase Methanol : water (50 : 50)

Reagents:
Acetonitrile, > 99.9%, VWR
Methanol, > 99.9%, VWR
Purified water, ≤ 50 ppb TOC, ≥ 18.2 M/cm, in house device

Column temperature: 20 - 25 ± 1 °C (set to 22 °C and kept constant by the analytical system)

Analytical monitoring:

no

Type:

Koc

Value:

0 other: value could not be determined due to the insolubility of the test item

Remarks on result:

not determinable

Remarks:

alue could not be determined due to the insolubility of the test item

Evaluation

As the retention times of the signals observed within the extracts of the test item were below that of the void time marker (sodium nitrate), the evaluation of the adsorption coefficients would not be feasibly and thus no further calculations were performed. Signals heights were compared for conclusions on the origin of the observed signals.

Void Time

HPLC void time t₀was determined by twofold injection of a solution of 10 mg/L sodium nitrate

Table 1:         Void Time of the System Suitability Test

 

Serial No.	t0 [min]
1	1.508
2	1.536

Reference Items

The retention time data of the reference items are given in Table 2.

Table 2:         Retention Times of the Reference Items

Reference Item	logKOCsoil	logKOC sewage sludge	tR [min]
4-Nitrobenzamide	1.93	1.52	3.665
Monuron	1.99	1.46	4.634
Linuron	2.59	2.43	8.119
Phenanthrene	4.09	4.35	14.271

 

Test Item Analysis

For each extraction medium and application rate, two signals were observed. The retention times were below that of the void time marker (sodium nitrate; seeTable 3).

Table 3:         Retention Times ofthe Test Item Samples

Test item amount [g/L]	Extraction-medium	Extraction step	Retention time [min]
			Signal 1	Signal 2
25	Acetonitrile	1	0.849	1.219
		2	0.848	1.227
50		1	0.851	n.d.
		2	0.853	n.d.
25	Methanol	1	0.883	1.273
		2	0.868	1.215
50		1	0.891	1.314
		2	0.876	1.229

n.d. = Not determined due to signal not being significant enough

Conclusions:

For each extraction, two test item signals were detected. As the retention times were below that of the void time marker (sodium nitrate), the evaluation of the adsorption coefficients would not be feasibly and thus no further calculations were performed.

Additionally it could be concluded, that the test item itself is insoluble within the selected solvents and the observed signals are originated from leached impurities.

A determination of the adsorption coefficients of the test item was deemed to be not possible acc. to OECD 121.

Executive summary:

The adsorption coefficient (KOC) for the test item non-graphitic carbon fiber on soil and on sewage sludge using high performance liquid chromatography (HPLC) was estimated according to OECD 121 (2001) and Council Regulation (EC) No. 440/2008, Method C.19 from2019‑12‑04 to 2019‑12‑11, at the test facility.

For test sample generation, the test item was extracted with acetonitrile and methanol at two different application rates with two replicates, respectively. Additionally a second, subsequent extraction was performed after the first extraction with new solvents. 

For each extraction, two test item signals were detected. As the retention times were below that of the void time marker (sodium nitrate), the evaluation of the adsorption coefficients would not be feasibly and thus no further calculations were performed. As the test item is poorly soluble, the observed signals are estimated to be caused by impurities leached from the test item instead of genuine test item components. This is also confirmed by reduced signal heights between the 1^stand 2^ndextraction.

The determination of the adsorption coefficients logKOC on soil and sewage sludge of the test item non-graphitic carbon fibre was deemed to be not possible acc. to OECD 121 as the test item is insoluble within the relevant solvents.

 

Reference 2

Endpoint:

adsorption / desorption: screening

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Conclusions:

In accordance with REACH Annex XI, section 2 the test can be omitted if due to the physico-chemical properties the proceeding of the test is technically not possible.
The adsorption coefficient (KOC) for the test item non-graphitic carbon fibre on soil and on sewage sludge using high performance liquid chromatography (HPLC) was estimated according to OECD 121 (2001) and Council Regulation (EC) No. 440/2008, Method C.19 (see entry Noack study 191120RW / CAH18859N" in section 5.4.1)

For test sample generation, the test item was extracted with acetonitrile and methanol at two different application rates with two replicates, respectively. Additionally a second, subsequent extraction was performed after the first extraction with new solvents. For each extraction, two test item signals were detected. As the retention times were below that of the void time marker (sodium nitrate), the evaluation of the adsorption coefficients would not be feasibly and thus no further calculations were performed. As the test item is poorly soluble, the observed signals are estimated to be caused by impurities leached from the test item instead of genuine test item components. This is also confirmed by reduced signal heights between the 1st and 2nd extraction.
Therefore, a determination of the adsorption coefficients of the test item was deemed to be not possible acc. to OECD 121.

Description of key information

The adsorption coefficient (KOC) for the test item non-graphitic carbon fiber on soil and on sewage sludge using high performance liquid chromatography (HPLC) was estimated according to OECD 121 (2001) and Council Regulation (EC) No. 440/2008, Method C.19 .

The determination of the adsorption coefficients log KOC on soil and sewage sludge of the test item non-graphitic carbon fibre was deemed to be not possible acc. to OECD 121 as the test item is insoluble within the relevant solvents.