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Water solubility

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Description of key information

Results  water solubiltiy of the substance is 54.2 mg/L ± 12.8 at 20 deg. C. 

Key value for chemical safety assessment

Water solubility:
54.2 mg/L
at the temperature of:
20 °C

Additional information

The water solubility of the test substance was determined by the shake flask method according to guidelines in OECD 105.


Quantitation of the water soluble components in the ZDDP (zinc dialkyldithiophosphate) submission substance was perfomred by GC-MS (gas chromatography-mass spectrometry) following derivatization of the water soluble portion to halogenated derivatives with pentafluorobenzyl bromide CASRN 1765 -40 -8. The derivitization procedure is described in "Structural determination of zinc dithiophosphates in lubricating oils by gas chromatography-mass spectrometry with electron impact and electron-capture negative ion chemical ionization" Journal of Chromatography A. 905(2001) 207 -222. The derivatization process cleaves the intact ZDDP (zinc dialkyldithiophosphate) molecule in two replacing the zinc atom with two pentafluorobenzyl branches forming two pentafluorobenzyl phosphorodithioic acid molecules, each with two alkyl groups, which can be separated and identified by GC-MS.


Results of the study indicate the water solubiltiy of the substance is 54.2 mg/L ± 12.8 at 20 deg. C. ZDDP components where alkydithiophosphate ligands contained C4 (isobutyl) groups accounted for the bulk of the composition of the water solubles ( approx. 93% by GC area).