Suspect Screening of OLED-Related Chemicals in Discarded Smartphone Screens

Organic light-emitting diode (OLED)
screens are widely
used in
smartphones and constitute an increasing component of the e-waste
stream, yet the chemical profiles and potential release of OLED screen
materials remain poorly understood. Here, we combined GC–HRMS
with an in-house suspect-screening library to identify and (semi)quantify
OLED-related compounds in discarded smartphone screens, separating
each screen into a display functional laminate (DFL) and a module
carrier layer (MCL). Twenty-four OLED-related compounds were identified,
including 22 confirmed with reference standards. Structurally, all
compounds contained at least two (hetero)aromatic rings and were grouped
into five classes: fused polycyclic aromatics, (hetero)biaryls, fluorene/spirobifluorene
derivatives, triarylamines, and carbazole motifs. At the whole-screen
level, the total chemical burden ranged from 2.24 to 14.6 μg
per screen. Across screens, six aryl boronic acids dominated the detected
mass, collectively contributing 83–99% of the total. Composition
profiles were broadly consistent across DFL samples, indicating similar
manufacturing practices. Compound- and mass-level comparisons between
DFL and MCL indicated chemical-specific distributions, suggesting
potential redistribution within the screen module during manufacturing,
use, dismantling, or disposal. Altogether, these results provide an
initial characterization of OLED-associated chemicals in waste screens
and inform future evaluations of chemical release and exposure in
e-waste contexts.