Application of flowerlike MgO for highly sensitive determination of lead via matrix-assisted laser desorption/ionization mass spectrometry.

RATIONALE: Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) is a high-throughput method to achieve fast and accurate identification of lead (Pb) exposure, but is seldom used because of low ionization efficiency and insufficient sensitivity. Nanomaterials applied in MS are a promising technique to overcome the obstacles of MALDI. METHODS: Flowerlike MgO nanostructures are applied for highly sensitive lead profiling in real samples. They can be used in two ways: (a) MgO is mixed with N-naphthylethylenediamine dihydrochloride (NEDC) as a novel matrix MgO/NEDC; (b) MgO is applied as an absorbent to enrich Pb ions in very dilute solution. RESULTS: The signal intensities of lead by MgO/NEDC were ten times higher than the NEDC matrix. It also shows superior anti-interference ability when analyzing 10 µmol/L Pb ions in the presence of organic substances or interfering metal ions. By applying MgO as adsorbent, the LOD of lead before enrichment is 1 nmol/L. Blood lead test can be achieved using this enrichment process. Besides, MgO can play the role of internal standard to achieve quantitative analysis. CONCLUSIONS: Flowerlike MgO nanostructures were applied for highly sensitive lead profiling in real samples. The method is helpful to prevent Pb contamination in a wide range. Further, the combination of MgO with MALDI MS could inspire more nanomaterials being applied in highly sensitive profiling of pollutants. Copyright © 2016 John Wiley & Sons, Ltd.