1-dodecylpyridinium chloride

Endpoint summary

Description of key information

Adsorption / desorption

The adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals (Experimental study report, 2018). A test item solution was prepared by accurately weighing 4 mg of test item and diluted with ACN up to10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 5.3. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances were chosen according to functional similarity with the test substance and calibration graph prepared. The reference substances were Xylene, Ethylbenzene, Toluene, Naphthalene, phenanthrene having Koc value ranging from 2.369 to 4.09. The Log Koc value of test chemical was determined to be 3.150 ± 0.002 at 25°C.This logKoc value indicates that the test chemical has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

Additional information

Adsorption / desorption

Various experimental studies of the test chemical were reviewed for the adsorption end point which are summarized as below:

 

In an experimental key study from study report (2018),the adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals (Experimental study report, 2018). A test item solution was prepared by accurately weighing 4 mg of test item and diluted with ACN up to10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 5.3. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances were chosen according to functional similarity with the test substance and calibration graph prepared. The reference substances were Xylene, Ethylbenzene, Toluene, Naphthalene, phenanthrene having Koc value ranging from 2.369 to 4.09. The Log Koc value of test chemical was determined to be 3.150 ± 0.002 at 25°C.This logKoc value indicates that the test chemical has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

 

For the test chemical, Soil adsorption coefficient (Koc) study was conducted for evaluating the adsorption capacity of test chemical onto different adsorbents (handbook, 1999). The adsorption of test chemical onto different adsorbents was examined at equilibrium conc. from 10 to 300 µM/l. Although Koc value of test chemical was not known, but it was reported that the adsorption maximum of test chemical for soils and compost was less than 10 µmol/g. There is no significant correlation between adsorption behaviour and organic matter contents in soils and composts. Thus, based on this, it indicates that the test chemical has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

On the basis of above overall results for test chemical, it can be concluded that the test chemical has a low to moderate sorption to soil and sediment and therefore have moderate to slow migration potential to ground water.