REPORT 

SANmZED 

DETERMINATION OF THE PARTITION COEFFICIENT {N ·OCTANOL/WATER) OF 

1,1,3,3·TETRAMETHYLBUTYL PEROXYPIVALATE 

NOTOX Proje1,(' -------·--; NOTOX Substanc.t _ 

-----~ 

· Page 1 of 17 -
sponsor. 

c 3 ~T !11A 

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The study described in this report has been correctly reported and was 

conducted in compliance with the most recent edition of: 

The OECD Principles of Good Laborqtory Practice 

which are essentially in conformity with: 

The United States Food and Drug Administration. Title 21 Code of Federal Regulations Part 58. 

The United States Environmental Protection Agency (FIFRA). Title 40 Code 

of Federal Regulations Part 160. 

The United States Environmental Protection Agency (TSCA). Tit1e·40 Code of 

Federal Regulations Part 792. 

Study Director 

Ir. M.J.C. Brekelmans 

\ Date~ '-.. 

Page 3 

Management 

J.A.M.W. van Helvoirt 

H ead-<J.f-Gh"'m.i.§..t ry Oat~" 
This report was audited by the NOTOX Quality Assurance Unit to ensure that 

the methods and results accurately reflect the raw data. 

The dates of Quality Assurance inspections and audits are given below. 

During the on-site inspections procedures applicable to this type of study 

were inspected. 

DATES OF QAU INSPECTIONS/AUDITS 

on-site inspection (s) 

17 July 1997 

protocol inspection (s) 

22 May 1997 

report audit (s) 

11 August 1997 

Head of Quality Assurance 

C.J. M.itchell B.Sc. 

--

\ 

Date\ /) 

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REPORTING DATES 

17 July 1997 

22 May 1997 

11 August 1997 
OECD Guidelines for Testing of Chemicals, Guideline No. 117~ 'Partition coefficient (n-octanol/water) High Performance Liquid Chromatography (HPLC) method' (adopted March 30, 1989). 

EEC directive 92/69 EEC, Part A, Methods for the determination. of physico- chemical properties, A.8: 'Partition coefficient', EEC Publication no. L383, December 1992. 

In the HPLC chromatograms of 1,1,3,3-TETRAMETHYLBUTYL PEROXYPIVALATE using spectrophotometric detection at 205 nm, 4 peaks were observed and therefore 4 P0w values were determined. For the major component of 1,1,3,3-TETRAMETHYLBUTYL PEROXYPIVALATE, the Pow value was 8.08 ' 104 (log P0w ~ 4.9). For the impurities, Pow values were 1.29 • 105 (log Pow~ 5.1), 1.49 • 105 (log Pow~ 5.2) and 1.45 • 106 (log P0w ~ 6.2). The temperature of the mobile phase was between 24.2 and 24.4 'C during the measurements. 

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Study Monitor 

Testing Facility 

Study Director 

Study plan 

TEST SUBSTANCE 

Identification 

Chemical name 

CAS No. 

Description 

Batch 

Purity Test substance storage Stability under storage 

conditions 

Expiry date 

( ~~ ) 

NiiTOXB:-·v-:----~--/ 

Hambakenwetering 3 

5231 DO 's-Hertogenbosch 

T-lw--N.e~. r· ~~ ----

_/ Sta;T23JU]y1997- -

Comp 1 eted: 23 Ju.l y 1997 

1,1,3,3-tetramethylbutyl peroxypiva1ate Propaneperoxic acid, 2,2-dimethy1-,1,1,3,3- tetramethy1buty1 ester (9CI) 

22288-41-4 

ColorJrlA~A 1inuid 

Csee-GeF1:4·f-ivat:-~ of Analysis In freezer in the dark 

Stable 

Not indicated 

The sponsor is responsible for the completeness and GLP Compliance of all 

test substance data. 

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The partition coefficient (n-octanol/water) (P0w) is defined as the ratio of the equilibrium concentrations in a two phase system consisting of n·octanol and water. 

Four different methods are available for the determination of the 

partition coefficient. The principle of each method is described below: 

1. Flask-shaking method Dissolved test substance is mixed thoroughly with n-octano1 and water. After phase separation, the concentration of the test substance in both phases is determined by a suitable analytical method. 

2. HPLC-method 

A solution of the test substance is injected onto a reversed-phase HPLC-column. The log P0w·value is calculated from the retention time of the test substance. 

3. Estimation from the water solubility and n-octanol solubility The solubility of the test substance in n-octanol and in water is determined. The quotient of the n-octanol- and water solubility is a rough estimation of the partition coefficient. 

4. Calculation from the structural formula 

Calculation methods are based on the theoretical fragmentation of the molecule into suitable substructures for which reliable log P w increments are known. The log P0 is obtained by summing the fragment values and the correction terms for intramolecular interactions. Lists 

of fragment constants and correction terms are available. 

Based on information supplied by the sponsor, the logPow of 1,1,3,3- TETRAMETHYLBUTYL PEROXYP!VALATE was expected to be between 0 and 6. Therefore, the HPLC method was chosen for the determination of the 

partition coefficient (n-octanol/water). 

Page 7 · 
Organization for Economic Co-operation and Development (OECD}, OECD Guideline for Testing of Chemicals, Guideline No. 117: 'Partition coefficient (n-octanol/water} High Performance Liquid Chromatography 

(HPLC} method' (adopted March 30, 1989}. 

European Economic Community (EEC], EEC directive 92/69 EEC, Part A, Methods for the determination of physico-chemical properties, A.8: 

'Partition coefficient', EEC Publication no. L383, December 1992. 

ARCHIVING 

NOTOX B.V. will archive the following data for at least 10 years: 

protocol, report, test substance reference sample and raw data. 

- Page 8 
The test system is recognized by the international guidelines (OECD, EEC). 

REFERENCE SUBSTANCES/HPLC METHOD 

Six chemicals for which log P0w has been reported were used to calibrate the elution time in units of log Pow· The mixture of reference substances consisted of: 

Reference substance 

nitrobenzene (z.s., Merck) 

toluene (p.a., Merck} bromobenzene (99%, GC, Aldrich Chemie Co., Inc, USA) 

1,4·dichlorobenzene {z.s., Merck} 

1,2,4-trichlorobenzene (LiChrosolv, Merck} 

2,4-DDT {99%, HPLC, Riedel de Haen, Seelze, Germany} 

1 log Paw values according to the OECD guideline. 

- Page 9 

log Pow' -"-"---/ 

1.9 

2.7 

3.0 

3.4 

4.2 

6.2 
and 2 gil. A mixture of the reference substances was prepared by adding 50 ~1 of each solution to a volumetric flask. Subsequently, this flask was 

made up with mobile phase to a final vo1ume of 10.0 m1. 

For the determination of t 0 (retention time of the unretarded component), 

a solution of formamide (p.a., Merck, Darmstadt, Germany) in methanol was 

prepared at a concentration of 1.5 gil and thereafter diluted 10 times with mobile phase, 

A stock solution of 1,1,3,3-TETRAMETHYLBUTYL PEROXYPIVALATE was prepared 

by dissolving 58,5 mg test substance in 50.0 m1 acetonitrile. The stock solution was diluted 25 times with mobile phase, resulting in the test 

solution. The corresponding blank solution was prepared by dissolving acetonitrile 25 times with mobile phase. 

Performance of the test 

The solutions were injected in the following sequence: the mixture of 

reference substances, mobile phase, the formamide solution, the test 

solution (in duplicate), the corresponding blank solution, the mixture of 

reference substances and the formamide solution. The chromatograms were 

recorded for approximately 15 minutes. 

Temperature of measurement 

The temperature of the mobile phase was recorded intermittently during the 

measurements. 

Page 10 
Column 

Mobile phase 

Flow 

Detection 

Injection volume 

DATA HANDLING 

LiChrospher 100 RP·18; 125 x 4 (I.D.) mm; d ~ 5 ~m (Merck, Darmstadt, Germany) 78/30 (v/v) acetonitrile (HPLC-grade, Labscan Limited Co., Dublin, Ireland)/Milli·Q water (Millipore Corp., Bedford, MA, USA) 1 ml/min 

UV at ~= 205 nm for the test substance and and the blank solution and A~ 210 nm for the 

references and formamide. 

100 ~1 for the test substance and the blank solution and 10 ~1 for the references and 

formamide. 

1. The capacity factor (k') is calculated from the retention of the substance concerned (tr) and the unretarded component (t 0 ): 

k' = (tr · t 0 )/t0 

2. Using the capacity factors of the reference substances, a plot of log P0w (x-value) versus log k' (y-value) was constructed, using linear regression analysis. The log Pow value of each component of the test substance was calculated from the following equation: 

log k'~ a'log Pow+ b 

Using high performance liquid chromatography, especially large log P0w values (between 0 and 6) can be accurately determined from the liquid chromatographic retention data. 

Page 11 
In the HPLG chromatograms of 1,1,~ETRAMETHYLBUTYL PEROXYPIVALATE, using 

detect ion at 205 nm, one large a~ ...,sma 11 peaks were observed. It was 

assumed that the large peak derives rrom the major component of test 

substance whereas the small peaks derives from impurities. 

The t 0 was determined to be 0.96 minutes as a mean value of both measurements (i.e 0.96 and 0.96 minutes). 

The mean values of the retention times, k' values, log k' values, 

log P0w and P0w values are summarized in Table 1. 

Table 1 Results of the test. 

Substance tr ' ' k ' log k log Pow 

nitrobenzene 1. 73 0.802 -0.096 1.9 

toluene 2.65 1.760 0.246 2.7 

bromobenzene 2.85 1. 969 0.294 3.0 

1,4-dichlorobenzene 3.50 2.641 0.422 3.4 1,2,4-trichlorobenzene 5.06 4.268 0.630 4.2 

2,4-DDT 12,50 12.016 1.080 6.2 

test substance 

lr2.eA.L_U.major component} 6.78 6.057 -0.782 -~ 4.9 :_ -"- - - - ·---· -- - ---

-

~ 

-~ 

---- ( 

Pow 

1--~. oa xlO~ , 

----------~ 

-

----•~-~---· -~~---""•~·~--~ 

A= 

Mean value of the retention times of both chromatograms. 

Interpolated from the regression line: y • 0.263x · 0.510 {r•0.991, n•6) 

Note: The calculations were performed using not rounded values. 

The temperature of the mobile phase was 24.2-24.4'C during the 

measurements. 

Page 12 
!HWHEL R 

( 

component 1 

Figure 1 HPLC chromatogram of a 46.8 mg/1 1,1,3,3-TETRAMETHYLBUTYL- PEROXYPIVALATE solution recorded at ~= 205 nm. 

Note: The peaks between 0 and 6 minutes were also observed in the chromatograms of the blank {see Figure 2). Therefore it was assumed that these peaks did not derive from the test substance. 

Page 13 
Figure 2 HPLC chromatogram of a blank recorded at 205 nm. 

Page 14 
1 ~ nitrobenzene 

2 ~ toluene 

3 ~ bromobenzene 

6 

4 = 1,4-dichlorobenzene 

5 ~ 1,2,4-trichlorobenzene 

6 = 2,4-DDT 

Figure 3 HPLC chromatogram of the mixture of reference substances in mobile phase recorded at A= 210 nm. 

Page 15 

2 

3 

1 
CHAMHEL R 

Figure 4 HPLC chromatogram of a 0.15 g/1 formamide solution in mobile phase recorded at ).~ 210 nm. 

Page 16 
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Satehhiil~ber 

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p

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· Page 17