Synthesis of highly fluorescent water-soluble silver nanoparticles for selective detection of Pb(ii) at the parts per quadrillion (PPQ) level - Chemical Communications (RSC Publishing)
Conversion of 3 parts per quadrillion to centimeter/meter
A sensitive vesicle mediated dispersive liquid-liquid microextraction of parts per quadrillion levels of beryllium from seawater samples prior to graphite furnace atomic absorption spectrometry determination - ScienceDirect