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Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
07 Oct 2009 to 16 Mar 2010
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: While permitted under suitability of the calibration set for the notified substance is low.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report date:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: EEC Directive 92/69, Part A.8 "Partition coefficient" Council Regulation (EC) No. 440/2008, Part A.8 "Partition coefficient"
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of method:
HPLC method
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): MTDID 8191
- Substance type: UVCB material
- Physical state: Yellowish liquid
- Concentration of oligomers: ≥99 %
- Stability under test conditions: Not reported
- Storage condition of test material: In the refrigerator at about 5 °C
- Other:

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficient
Type:
log Pow
Partition coefficient:
0.16 - 7.28
Temp.:
25 °C
pH:
6.83 - 6.87
Details on results:
The retention times for all reference substances in both the first main test and the second main test are reported in Table 2. The calibration curve of the first main test is depicted in Figure 1 (SEE ATT 1). The calibration curve for the second main test is depicted in Figure 2 (SEE ATT 2).

The regression equation for the first main test was:
log k' = 0.319 x log Pow - 0.827 (r = 0.998, n = 6)

The regression equation for the second main test was:
log k' = 0.270 x log Pow - 1.464 (r = 0.985, n = 6).

Any other information on results incl. tables

In support of the HPLC assessment of partition coefficient, log Pow was estimated using experimentally-determined values for octanol and water solubility. The calculated value was log Pow = 4.32, which is within the range specified as appropriate for HPLC determination of partition coefficient. Because the test substance is a UVCB material, the HPLC approach is regarded as especially suitable for measurement of log P.

While the elution of peaks differs between the two main tests, the distribution of log P values between the two tests is similar (Tables 3 and 4). This result suggests that molecular weight effects are not important in partitioning behaviour.

Greater than 50% of the components of the test substance have log P values between 4.0 and 5.3 as determined in the first main test and greater than 50% between 3.8 and 5.5 as determined in the second main test. The proportion of the components has been calculated from the peak areas of the respective peaks based on the assumption that the general structure of the major components is very similar and therefore a similar UV absorption is expected. Consequently, the area percent has been equated with weight percent.

Table 2, Retention time and partition data for reference substances in the first and second main tests
Substance Concentration tr,1 tr,2 tr,3 tr,4 tr,5 tr,6 tr,mean log k'A
1st Main Test  
Unretained substance:  
Thiourea (t0) 106 mg/L 1.375 1.379 1.378 1.378 1.38
Reference substances:  
Acetanilide 99.5 mg/L 1.752 1.752 1.749 1.748 1.748 1.749 1.75 -0.57
Benzyl alcohol 100 µL/L 1.834 1.835 1.832 1.830 1.830 1.832 1.83 -0.48
2,3-Dichloroaniline 123.6 mg/L 3.140 3.141 3.134 3.132 3.135 3.138 3.14 0.11
Diphenylamine 134 mg/L 4.272 4.280 4.268 4.261 4.269 4.272 4.27 0.32
Triphenylamine 90.8 mg/L 15.209 15.246 15.216 15.194 15.232 15.232 15.22 1.00
2,4-DDT 109.7 mg/L 22.860 22.884 22.847 22.830 22.860 22.851 22.86 1.19
   
2nd Main Test  
Unretained substance:  
Formamide (t0) 100 µL/L 2.196 2.206 2.200 2.20
Reference substances:  
Acetanilide 99.5 mg/L 2.316 2.320 2.313 2.310 2.310 2.309 2.31 -1.29
2,3-Dichloroaniline 123.6 mg/L 2.691 2.700 2.691 2.685 2.684 2.682 2.69 -0.65
Diphenylamine 134 mg/L 2.832 2.844 2.836 2.828 2.826 2.824 2.83 -0.54
1,2,4-Trichlorobenzene 100 µL/L 3.683 3.708 3.697 3.682 3.677 3.674 3.69 -0.17
Triphenylamine 90.8 mg/L 4.641 4.683 4.666 4.644 4.634 4.630 4.65 0.05
2,4-DDT 113 mg/L 5.752 5.811 5.786 5.756 5.742 5.740 5.76 0.21
A. Log k' = log (tr,mean- to) / to)

Table 3, Retention time, logP results and Area percent data for the test substance, 1st main test
Test Item Peak Retention Time (min) log k'A logPB Peak Area Mean Area Percent of Total
1st run 2nd run 3rd run 1st run 2nd run 3rd run 1st run 2nd run 3rd run Mean
1 1.676 1.675 1.670 -0.66415 -0.66560 -0.67297 0.51 0.51 0.48 0.50 18299.0 3.33
2 1.941 1.939 1.934 -0.38820 -0.38974 -0.39363 1.38 1.37 1.36 1.37 10987.0 2.00
3 2.460 2.456 2.451 -0.10466 -0.10627 -0.10829 2.27 2.26 2.25 2.26 8394.3 1.53
4 3.214 3.207 3.203 0.12490 0.12324 0.12229 2.99 2.98 2.98 2.98 10395.7 1.89
5 3.350 3.342 3.336 0.15593 0.15416 0.15283 3.08 3.08 3.07 3.08 4213.0 0.77
6 4.753 4.737 4.735 0.38925 0.38718 0.38692 3.82 3.81 3.81 3.81 6997.7 1.27
7 5.189 5.170 5.167 0.44200 0.43983 0.43949 3.98 3.97 3.97 3.98 64512.0 11.75
8 7.517 7.484 7.484 0.64904 0.64670 0.64670 4.63 4.62 4.62 4.63 101757.7 18.53
9 11.173 11.123 11.106 0.85194 0.84971 0.84895 5.27 5.26 5.26 5.26 46125.0 8.40
10 11.516 11.465 11.448 0.86688 0.86469 0.86396 5.31 5.31 5.30 5.31 70651.7 12.86
11 12.658 12.605 12.585 0.91324 0.91119 0.91042 5.46 5.45 5.45 5.45 7973.3 1.45
12 16.906 16.824 16.807 1.05204 1.04974 1.04926 5.89 5.89 5.89 5.89 6231.3 1.13
13 17.445 17.378 17.346 1.06686 1.06504 1.06417 5.94 5.94 5.93 5.94 64515.3 11.75
14 18.280 18.218 18.176 1.08886 1.08726 1.08618 6.01 6.01 6.00 6.01 29534.7 5.38
15 19.130 19.073 19.032 1.11017 1.10877 1.10776 6.08 6.07 6.07 6.07 14886.7 2.71
16 26.741 26.642 26.581 1.26512 1.26342 1.26237 6.56 6.56 6.55 6.56 13441.0 2.45
17 27.982 27.894 27.835 1.28586 1.28442 1.28346 6.63 6.62 6.62 6.62 46076.3 8.39
18 29.377 29.250 29.215 1.30806 1.30608 1.30554 6.70 6.69 6.69 6.69 16731.7 3.05
19 30.173 30.114 30.009 1.32023 1.31934 1.31775 6.74 6.73 6.73 6.73 7461.3 1.36
Sum, Peaks 7-10 283046.4 51.54
Sum, Peaks corresponding to logP ≥ 3.0 501108.7 91.25
Sum, Peaks corresponding to logP ≥ 4.0 489898.0 89.2
Sum, Peaks corresponding to logP ≥ 4.5 425386.0 77.5
Sum, All Peaks                   549184.7 100.00
A. Log k' values calculated from individual retention times as log k' = log (tr- t0) / t0
B. LogP values calculated from regression equation using individual log k' values

Table 4, Retention time, logP results and Area percent data for the test substance, 2nd main test
Test Item Peak Retention Time (min) log k'A logPB Peak Area Mean Area Percent of Total
1st run 2nd run 3rd run 1st run 2nd run 3rd run 1st run 2nd run 3rd run Mean
1 2.142 2.160 2.184 <1.0 8497.0 0.60
2 2.285 2.283 2.285 -1.41655 -1.42698 -1.41655 0.18 0.14 0.18 0.16 30015.0 2.13
3 2.358 2.355 2.358 -1.14573 -1.15409 -1.14573 1.18 1.15 1.18 1.17 18895.7 1.34
4 2.512 2.507 2.510 -0.84933 -0.85636 -0.85213 2.27 2.25 2.26 2.26 10188.3 0.72
5 2.627 2.622 2.626 -0.71280 -0.71793 -0.71382 2.78 2.76 2.77 2.77 15358.7 1.09
6 3.009 2.999 3.004 -0.43496 -0.44037 -0.43766 3.81 3.79 3.80 3.80 138330.3 9.80
7 3.368 3.354 3.361 -0.27536 -0.28060 -0.27797 4.40 4.38 4.39 4.39 210943.3 14.94
8 3.897 3.877 3.886 -0.11304 -0.11819 -0.11587 5.00 4.98 4.99 4.99 252151.7 17.86
9 4.597 4.568 4.579 0.03699 0.03171 0.03372 5.55 5.53 5.54 5.54 162903.3 11.54
10 4.737 4.700 4.714 0.06165 0.05527 0.05770 5.64 5.62 5.63 5.63 79290.3 5.61
11 5.682 5.636 5.654 0.19919 0.19341 0.19568 6.15 6.13 6.14 6.14 195263.3 13.83
12 7.183 7.115 7.142 0.35488 0.34891 0.35129 6.73 6.71 6.71 6.72 161604.3 11.44
13 8.952 8.862 8.892 0.48684 0.48101 0.48296 7.22 7.19 7.20 7.20 52992.7 3.75
14 9.298 9.201 9.246 0.50854 0.50256 0.50535 7.30 7.27 7.28 7.28 75724.7 5.36
Sum, Peaks 6-10 764328.6 54.12
Sum, Peaks corresponding to logP ≥ 3.0 1329203.9 94.13
Sum, Peaks corresponding to logP ≥ 4.0 1190873.6 84.3
Sum, Peaks corresponding to logP ≥ 4.5 979930.3 69.4
Sum, All Peaks                   1412158.7 100.01
A. Log k' values calculated from individual retention times as log k' = log (tr- t0) / t0
B. LogP values calculated from regression equation using individual log k' values

FIGURE 1 --> SEE ATT 1

FIGURE 2 --> SEE ATT 2

Applicant's summary and conclusion

Conclusions:
The n-octanol:water partition coefficient (logP) of components within the UVCB test substance ranged from 0.16 to 7.28 at pH 6.87, 25°C
Executive summary:

The n-octanol:water partition coefficient of the test substance (CAS1101874-33-2), a UVCB material, was assessed using an HPLC method at 25 °C and neutral pH. The test was performed twice using two different C18 stationary phases and a 75:25 (v/v) acetonitrile:water mobile phase which was isocratic during elution of the analyzed fragments. Nineteen peaks were reported in the first main test, and fourteen peaks were reported in the second main test. The retention times for peaks 1-19 corresponded to a logP range of 0.50 to 6.73 in the first test. The retention times for peaks 2-14 corresponded to a logP range of 0.16 to 7.28 in the second test, and peak 1 eluted with the unretained formamide standard (log P undefined). The logP range is therefore reported as 0.16 to 7.28.

The study was conducted under internationally-accepted test guideline OECD117 and was compliant with GLP standards. The test substance is a UVCB-material containing mostly oligomeric materials plus a small amount of residual materials. The reference substances were chosen from the candidates described in the method guideline and are acceptable in principle. However, the reference standards employed in this study are of limited utility for this test substance, owing to differences in chemical characteristics of aromatic and aliphatic compounds and poor representation of test substance functional groups among the calibration set. The study is therefore classified as reliable with restrictions.