2-Butanone, 1,3,4-trihydroxy-

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003-06-30 to 2003-06-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

the applied method is similar to that of the OECD TG 117 and OECD TG 121

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:

The study procedure described in this report was based on the following guideline proposal:

Organization for Economic Co-operation and Development (OECD), OECD Guideline for
Testing of Chemicals, Proposal for a new guideline 121: “Estimation of the Adsorption
Coefficient (K) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC)”, January 2001.

Deviations:

not specified

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD 117: "Partition coefficient (n-octanol/water) High Performance Liquid Chromatography (HPLC) method"

Version / remarks:

adopted March 30 1989

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Specific details on test material used for the study:

- Name: (S)-1,3,4-trihydroxybutan-2-one
- CAS no.: 533-50-6
- Description: clear orange-yellow viscous liquid

Radiolabelling:

no

Test temperature:

35 °C (column temperature)

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: not specified
- Type: HPLC
- Type, material and dimension of analytical (guard) column: Hypersil BDS-CN; 150 x 4.6 (I.D.) mm; dp = 2 5 µm (Alltech, Deerfield, USA)
- Flow: 1 mL/min
- Injection volume: 10 µL
- Detection system: spectrophotometric detector (UV at lambda= 210 nm)

MOBILE PHASE: 55/45 (v/v) methanol/Milli-Q water
- Methanol: HPLC-grade, Labscan, Dublin, Ireland
- Milli-Q water: Tap water purified by reversed osmosis and subsequently passed over activated carbon and ion-exchange cartridges; Millipore, Bedford, MA, USA

Using a computer calculation program, pKa values were calculated for the test item to be:
- 2.75 and - 2.78 basic group (RCH2OH)
13.71 acidic group (RRCHOH)
15.30 and 17.08 acidic group (RCH2OH)

Based on this the test substance is always in the non-ionized form in the pH range 5.5 - 7.5. Therefore, the mobile phase was not buffered during the performance of the test.

STATIONARY PHASE: cyanopropyl chemically bound resin on silica basis (Hypersil BDS-CN)

PREPARATION OF THE SOLUTIONS
A solution of the reference substance in Methanol, at a concentration of 1.3 g/L, was used. This solution was diluted by a factor of 10 with mobile phase. The reference substance was prepared by adding 500 µL of the reference substance solution to a 5 mL volumetric flask. Subsequently, this flask was filled up to the mark with mobile phase. As reference blank solution, 10 % methanol in mobile phase was used. A 5.4 g/L solution of formamide in methanol was diluted by a factor 10 with mobile phase. This solution was used for the determination of t0 (retention time of the unretarded component). As blank formamide solution, 10 % methanol in mobile phase was used. A 925.2 mg/L stock solution of Erythrulose was prepared in mobile phase. The test solution was prepared by diluting the stock solution by a factor 10 with mobile phase. As blank solution mobile phase was used.


DETERMINATION OF DEAD TIME
- Method: by inert substance which is not retained by the column; 5.4 g/L solution of formamide (>= 99.5%, Acros Organics, Geel, Belgium) in methanol (HPLC-grade, Labscan, Dublin, Ireland) diluted by factor 10 with mobile phase; solution used for determination of t0 (retention time of the unretarded component); as blank formamide solution, 10 % methanol in mobile phase used

REFERENCE SUBSTANCES
- Identity: Phenol (99 %, Acros organics, Geel, Belgium); log Koc value according to draft OECD TG 121 is 1.32

PERFORMANCE
The solutions were injected in the following sequence: mobile phase, the reference substance, the reference blank solution, the formamide solution, the reference blank solution, the test solution (in duplicate), the corresponding blank solution, the reference substances and the formamide solution. The chromatograms were recorded for 5 minutes.

EVALUATION
- Calculation of capacity factors k': calculated from retention of the substance concerned (tr) and the
unretarded component (t0): k’ = (tr – t0)/t0
- Determination of the log Koc value: Using capacity factors of the reference substances, plot of log Koc (x-value) versus log k’ (y-value) constructed, using linear regression analysis; log Koc value of each component of test substance calculated from equation: log k’ = a * log K + b

The pKa values for the test item were calculated using pKalc version 5.0. (module in PALLAS version 3.0), an expert system for the calculation of pKa values.

Key result

Sample No.:

#1

Type:

log Koc

Value:

< 1.32 dimensionless

Temp.:

35 °C

Remarks on result:

other: HPLC method

Key result

Sample No.:

#1

Type:

Koc

Value:

< 20.9 dimensionless

Temp.:

35 °C

Remarks on result:

other: HPLC method

Details on results (HPLC method):

In the HPLC chromatograms of the test item, using detection at 210 nm, one large and two small test substance peaks were observed. It was assumed that the large peak derives from the major component of the test substance whereas the small peaks derive from impurities.
- Representative HPLC chromatograms of the test solution, the blank (mobile phase), the reference substance, and the formamide solution are attached.
- Average retention data for test substance: t0 was determined to be 1.981 minutes as a mean value of both measurements (i.e. 1.983 and 1.979 minutes); mean values of the retention times tr are summarized in the table of below section “Any other information on results incl. tables”
- Overall result: The adsorption coefficient (Koc) of the test item was determined to be < 20.9 (log Koc < 1.32) at 35°C.

Transformation products:

not specified

Statistics:

The pKa values for the test item were calculated using pKalc version 5.0.

Table: Results of the test

Substance	tr1	k'	log k'	log Koc	Koc
Reference substance (Phenol)	2.389	0.206	-0.687	1.32	20.9
Test substance:
- Peak 1	1.108	-0.441	< -0.687	< 1.32	< 20.9
- Peak 2	1.448	-0.269	< -0.687	< 1.32	< 20.9
- Peak 3	1.962	-0.010	< -0.687	< 1.32	< 20.9

Validity criteria fulfilled:

yes

Remarks:

the study is considered valid

Conclusions:

In a study equivalent to OECD TG 121 using a HPLC method the adsorption coefficient (Koc) of the test item was determined to be < 20.9 (log Koc < 1.32) at 35 °C.

Executive summary:

The estimation of the adsorption coefficient (Koc) in soil and on sewage sludge using High Performance Liquid Chromatography (HPLC) was based on the draft OECD TG 121 (January 2001), which is similar to OECD TG 117. A High Performance Liquid Chromatograph with a spectrophotometric detector was used. The stationary phase was a cyanopropyl chemically bound resin on silica basis (Hypersil BDS-CN). The mobile phase was 55/45 (v/v) methanol/water. A temperature controlled column compartment at 35 °C was used. According to the OECD guidelines, the estimation of the adsorption coefficient (Koc) for test substances that are ionized for at least 10 % within pH 5.5 to 7.5, should be performed with both the ionized and non-ionized form. The pKa values were calculated using a computer calculation program (13.71, 15.30 and 17.08 for acidic groups and - 2.75 and - 2.78 for basic groups in the test substance molecule). In the HPLC chromatograms of the test item, using detection at 210 nm, one large and two small test substance peaks were observed. It was assumed that the large peak derives from the major component of the test substance whereas the small peaks derive from impurities. From this, it was decided to perform the HPLC method at neutral pH. As a result, the adsorption coefficient (Koc) of the test item was determined to be < 20.9 (log Koc <  1.32) at 35 °C.

Key value for chemical safety assessment

Koc at 20 °C:

20.9