oligomeric Reaction products from Hydrogenation and Hydrolysation of Starch

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Mar - Jun 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

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))

Test guideline 2

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))

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:

-

EC Number:

473-690-8

EC Name:

-

Cas Number:

738602-93-2

Molecular formula:

not applicable for UVCB

IUPAC Name:

(2R,3R,4S,5S,6R)-2-{[(2R,3R,4R,5S,6R)-5-{[(2R,3R,4R,5S,6R)-3,4-dihydroxy-6-(hydroxymethyl)-5-{[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}oxan-2-yl]oxy}-3,4-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}-6-(hydroxymethyl)oxane-3,4,5-triol; (2S,3R,5R)-4-{[(2R,3R,4R,5S,6R)-5-{[(2R,3R,4R,5S,6R)-3,4-dihydroxy-6-(hydroxymethyl)-5-{[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}oxan-2-yl]oxy}-3,4-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}hexane-1,2,3,5,6-pentol

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source (i.e. manufacturer or supplier) and lot/batch number of test material: Sponsor, Batch 4G08
- Purity, including information on contaminants, isomers, etc.: 54.2 % Maltotriosyl glucoside


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature at about 20 °C away from direct sunlight

Study design

Test temperature:

25 °C

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Merck-Hitachi pump L-6200
Merck-Hitachi autosampler L-7450
Merck-Hitachi UV/Vis detector L-4000
Sedex ELSD detector 85
Jones Column oven 7990
- Type: HPLC
- Type, material and dimension of analytical (guard) column: Lichrospher 100 CN, pre-column CN
- Detection system: UV VIS, ELSD

MOBILE PHASES
- Type: water/methanol (45:55 v/v%)
- Experiments with additives carried out on separate columns: no
- pH: 6.8
- Solutes for dissolving test and reference substances:

DETERMINATION OF DEAD TIME
- Method: by inert substances which are not retained by the column (sodium nitrate)

REFERENCE SUBSTANCES
- Identity: isoproturon, linuron, 2,4-DDT, diclofop-methyl, acetanilide, pyrazophos

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 8.23 µg/ml, 100 µl
- Quantity of reference substances:
isoproturon 10.64 mg, 135 µl
linuron, 10.53 mg, 55 µl
2,4-DDT, 13.05 mg, 250 µl
diclofop-methyl, 10.56 mg 180 µl
acetanilide, 10.83 mg, 140 µl
pyrazophos 20.97 mg 800 µl
dilute to 10 mL with mobile phase,
100 µl injected
- Intervals of calibration: 6

REPETITIONS
- Number of determinations: 3

EVALUATION
- Calculation of capacity factors k': calculated from the retention time of the reference items, the test item and an un-retarded item
- Calculation of retention times: no specific calculation
- Determination of the log Koc value: by linear regression

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Key result

Sample No.:

#1

Type:

Koc

Value:

0.32

pH:

6.8

Temp.:

25 °C

Adsorption coefficient 2

Key result

Sample No.:

#2

Type:

Koc

Value:

0.304

pH:

6.8

Temp.:

25 °C

Adsorption coefficient 3

Key result

Sample No.:

#3

Type:

Koc

Value:

0.393

pH:

6.8

Temp.:

25 °C

Results: HPLC method

Details on results (HPLC method):

- Retention times of reference substances used for calibration (min):
Acetanilide 3.12
Isoproturon 3.63
Linuron 4.58
Pyrazophos 5.91
Dicolfop-methyl 6.91
2,4-DDT 10.67
- Details of fitted regression line (log k' vs. log Koc):
Y = a+b*x
Y = log k' values
X = log Koc values
b = 0.162
a=-0.051
r = 0.999
- Average retention data for test substance: 2.23 min

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In conclusion, the log of the adsorption coefficient of MG-60 was estimated to be log Koc -0.5 which is equal to a Koc value of 0.3 using the HPLC method. This value indicates that MG-60 will not be adsorbed by organic carbon in soil. MG-60 is very mobile.

Executive summary:

The determination of the adsorption coefficient (Koo) of MG-60 was performed according to the OECD Guideline for the Testing of Chemicals, No. 121, Estimation of the Adsorption Coefficient (Koo) on Soil and Sewage Sludge using High Performance Liquid Chromatography (HPLC), January, 2001 and the EC Directive 2001/59, C.19.

The test item solution was injected three times and the combined reference solution was injected six times. The test item is not UV detectable. Therefore, ELSD was used for the detection. Only three of the reference compounds (isoproturon, pyrazophos and diclofop- methyl) were ELSD detectable. Therefore, the ELSD signal of the test item was corrected using a time increment A t, to adjust for the time difference between UV and ELSD detection times. This time increment was determined with isoproturon, pyrazophos and diclofop-methyl.
The retention time of the test item was determined to be below the lowest reference item used (acetanilide). Thus, the log Koc of MG-60 was determined to be < 1.25. By extrapolating the regression curve, the log Koc of the test item was calculated to be -0.5, corresponding to a Koc value of 0.3.
In the present study the reference items covered the range of log Koc 1.25 to log Koc 5.63.

The chromatography of the test item resulted in one main peak with a well-defined and reproducible retention time. The HPLC method was therefore considered to be suitable for the purpose of the study. Based on the chromatographic data, MG-60 was considered to be stable during the test procedure.
The retention times of the individual measurements of the reference items, test item and the dead time are reported. The capacity factor (k') was calculated for each reference item using the retention times. Log KOc was plotted versus log k for each component to obtain a regression curve.