Charcoal

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-08-03 to 2010-08-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted in accordance OECD no. 121 resp. EU method C.19

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

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

Principles of method if other than guideline:

HPLC is performed on analytical columns packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties. A moderately polar stationary phase based on a silica matrix is used. While passing through the column along with the mobile phase the test substance interacts with the stationary phase. As a result of partitioning between mobile and stationary phases the test substance is retarded. The dual composition of the stationary phase having polar and non-polar sites allows for interaction of polar and non-polar groups of a molecule in a similar way as is the case for organic matter in soil or sewage sludge matrices. This enables the relationship between the retention time on the colum and the adsorption coefficient on organic matter to be established.

GLP compliance:

no

Type of method:

HPLC estimation method

Media:

other: no palicable

Test material

Test material information

Constituent 1

Reference substance name:

Charcoal

EC Number:

240-383-3

EC Name:

Charcoal

Cas Number:

16291-96-6

IUPAC Name:

Carbón vegetal

Details on test material:

Name: Charcoal (Probe 2: C-Fix =80.5%)
Batch no.: 29004
Appearance: Charcoal typic
Composition: Charcoal
CAS no.: 16291-96-6
EINECS-no.: 240-383-3
Purity: C-Fix: 80.5%
Expiry date: Dec. 2030
Storage: Room temperature 20 ± 5 °C, keep away from humidity

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
no aplicable

Radiolabelling:

no

Study design

Test temperature:

25 +/- 1

HPLC method

Details on study design: HPLC method:

Pump: Dionex P580 Pump
Injector: Rheodyne 8125)
Column: Reprosil-Pur CN Dr. Maisch, 4.6 mm i.D., 125 mm length, particle size 3 µm
Detector: Dionex, UVD 170S
Column temperature was room temperature, 25 ± 1 °C.
Wavelength for evaluation: 220 nm
Mobile phase: Methanol/water (55/45% v/v)

Batch equilibrium or other method

Analytical monitoring:

not required

Details on sampling:

no aplicable

Details on matrix:

no aplicable

Details on test conditions:

no aplicable

Results and discussion

Adsorption coefficient

Type:

log Koc

Value:

< 1.5

Temp.:

25 °C

Results: HPLC method

Details on results (HPLC method):

The log KOC-value of the test item charcoal (Probe 2: C-Fix = 80.5%) lies outside the calibration range obtained with the used reference substances (1.32-5.63) and also outside the determinable log Koc-range of the HPLC screening method (according to OECD guideline 121: 1.5 - 5.0). Therefore, the log KOC of the test item should be stated as < 1.5.

Results: Batch equilibrium or other method

Adsorption and desorption constants:

no aplicable

Recovery of test material:

no aplicable

Concentration of test substance at end of adsorption equilibration period:

no aplicable

Concentration of test substance at end of desorption equilibration period:

no aplicable

Details on results (Batch equilibrium method):

no aplicable

Statistics:

no aplicable

Any other information on results incl. tables

El cálculo del factor de capacidad k': El factor de capacidad k' para cada pico se calcula como sigue:k '= (t_R- t₀) / t₀ ; con t_Rtiempo de retención, t_o tiempo muerto (tiempo de retención de nitrato de sodio).

La función de calibración se ha elaborado a partir de las seis mediciones de los factores de capacidad de los elementos de referencia. Al graficar el registro de valores de KOC los puntos de referencia contra los factores de capacidad media de registro y la realización de la regresión lineal, arrojan una función de calibración de la siguiente forma: y = ax + b, resultando el cálculo de log KOC :

Utilizando la ecuación de regresión lineal se calculó y determinó los factores de capacidad calculados para el producto de ensayo, para cada una de las tres mediciones del log K OC.

Por último, la media y la desviación estándar del log K OC se calcularon:

log= 0,2934 k' * log KOC - 0.32   r²  = 0,986.

 

 

Los tiempos de retención del pico obtenido después de la inyección de la solución producto de ensayo se presentan en la tabla siguiente:

-         Los tiempos de retención de elementos de prueba

Artículo de prueba Pico	T R [Min]
Medida 1	2,270
Medida 2	2,256
Medida 3	2,236
Media	2,254
La desviación estándar	0,017

 

-         Valor calculado: Factor de capacidad k ', log k', y el log K OC - elemento de la prueba

Artículo de prueba Pico	k '	logK '	log K OC
Medida 1	0,7606	-0,1188	0,686
Medida 2	0,7497	-0,1251	0,664
Medida 3	0,7342	-0,1342	0,633
Media			0,661
La desviación estándar			0,026

 

log K OC se calcula a partir del factor de capacidad k 'de la siguiente manera:

log K OC = (log k '+ 0,32) / 0,2934

Applicant's summary and conclusion

Validity criteria fulfilled:

no

Remarks:

no log Koc values of test item are outside the range of calibration

Conclusions:

The log Koc of the test item charcoal is stated as <1.5.