A rapid method for determining diethylene
glycol (DEG) in toothpaste based on the use of ultraperformance
liquid chromatography (UPLC) coupled to
time-of-flight mass spectrometry (TOF-MS) has been
developed. The method has been validated in toothpaste
samples spiked at different levels, 0.005, 0.1 and 5%,
obtaining satisfactory recoveries (74–98%) and relative
standard deviations (<4%). Quantification was carried out
by using matrix-matched standards calibration. The developed
method was applied to several types of toothpaste,
making identification and quantification of DEG and other
polyethylene glycols (PEG) feasible with very little sample
manipulation, as only extraction with water is required. The
excellent sensitivity of TOF-MS analysis performed in fullscan
acquisition mode allowed the determination of DEG at
concentration levels as low as 0.005% in samples and its
reliable identification via the mass accuracy measurements
provided by this instrument (<5 ppm
