(S)-3-methyl-2-(2-oxotetrahydropyrimidine-1-yl)butyric acid

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 10-12 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study was conducted according to an OECD Method and in accordance with GLP. The study material is well characterized.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

2000

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Version / remarks:

Derived from the 08.04.1993:2. Draft Guideline for testing of Chemicals:Screening method for the determination of the Adsorption-coefficient on Soil (KOC) (HPLC Method)

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

430-900-2

EC Name:

-

Cas Number:

192725-50-1

Molecular formula:

Hill formula: C9H16N2O3 CAS formula: C9H16N2O3

IUPAC Name:

3-methyl-2-(2-oxo-1,3-diazinan-1-yl)butanoic acid

Radiolabelling:

no

Study design

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: HPLC
- Type:Chromatointegrator Mod.D-2500 (Merck-Hitchi)
- Type, material and dimension of analytical (guard) column: hypersil CPS, 250 mm * 4.6 mm id; 5um particle size
- column temperature = room (20+/- 1oC)
- flow-rate = 0.75 mL/min
- Detection system: Mod. 4200 UV/Vis (Merck-Hitchi); wavelength = 214 nm

MOBILE PHASES
- Type: methanol water
- Solutes for dissolving test and reference substances:


REFERENCE SUBSTANCES
- Identity: Thiourea, atrazine, isoproturon, triadimenol, fenamiphos, linuron, azinphos methyl

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 10 ug/ml
- Quantity of reference substances: 10 ug/ml
Calibration curves were developed from retention time data for formamide and reference standard solutions

REPETITIONS
- Number of determinations: duplicate

EVALUATION
- Calculation of capacity factors k: Yes- calculated from the equation k = tr-t0/t0 where tr is retention time ( min) and t0= dead time( min)
- Determination of the log Koc value: yes- with reference to the calibration curve
- mean retention time for dead time( formamide) = 4.556 (SD = 0.005)

Results and discussion

Adsorption coefficient

Type:

log Koc

Value:

< 1.5

Results: HPLC method

Details on results (HPLC method):

FILL IN WHAT YOU CAN.....

Mean retention time for dead time = 4.556

Mean retention times for references substances used for calibration: 5.34 - 7.33

- Details of fitted regression line (log k' vs. log Koc):
intercept = -0.4644
SE residuals = 0.0382
SxO: 0.1192
Qxx = 134.9645
y-mean = 0.3649
Number of values = 24
log Koc = 2 log k' = -0.7208
log Koc = 3 log k' = -0.1935
X coefficient = 0.3544
SE X-coefficient = 0.0196
R2 = 0.9368
t(95,22): 2.0739
Confidence limits = 0.25
degrees of freedom = 22

- Average retention data for test substance: 2.5

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coeffcient of the components of the test material have been determined to be less than 1.5.

The test substance eluted with a lower retention time than thiourea. Its log Koc value was therefore outside the limits of the method and less than 1.5.