Screening of Indoor Transformation Products of Organophosphates and Organophosphites with an in Silico Spectral Database

Numerous transformation
products are formed indoors, but they are
outside the scope of current chemical databases. In this study, an
in silico spectral database was established to screen previously unknown
indoor transformation products of organophosphorus compounds (OPCs).
An R package was developed that incorporated four indoor reactions
to predict the transformation products of 712 seed OPCs. By further
predicting MS2 fragments, an in silico spectral database
was established consisting of 3509 OPCs and 28,812 MS2 fragments.
With this database, 40 OPCs were tentatively detected in 23 indoor
dust samples. This is the greatest number of OPCs reported to date
indoors, among which two novel phosphonates were validated using standards.
Twenty-four of the detected OPCs were predicted transformation products
in which oxidation from organophosphites plays a major role. To confirm
this, the in silico spectral database was expanded to include organophosphites
for suspect screening in five types of preproduction plastics. A broad
spectrum of 14 organophosphites was detected, with a particularly
high abundance in polyvinyl chloride plastics and indoor end-user
goods. This demonstrated the significant contribution of organophosphites
to indoor organophosphates via oxidation, highlighting the strength
of in silico spectral databases for the screening of unknown indoor
transformation products.