One-step membrane protected micro-solid-phase extraction and derivatization coupling to high-performance liquid...

Aliphatic aldehyde is a type of important organic material and precursor. However, some of them have been proved danger or harmful to health, especially those are occurred in food and cosmetics. Here, we reported a rapid and efficiency one-step membrane protected micro-solid-phase extraction and derivatization (μ-SPE-D) method for selectively determination of trace aliphatic aldehydes in complex cosmetic and food samples by coupling to high-performance liquid chromatography (HPLC). In this method, one-step extraction and derivatization strategy reduced the sample preparation time; membrane protected solid-phase extraction technology eliminated matrix interference; and the efficient sorbent mono-(6-(diethylenetriamine)-6-deoxy)-beta-cyclodextrin- ploy(styrene-divinylbenzene-methacrylic acid) (NH₂-β-CD-Poly(St-DVB-MAA)) guaranteed the selective adsorption of aliphatic aldehydes. The sorbent, NH₂-β-CD-Poly(St-DVB-MAA), was prepared via chemical fabrication and optimized carefully. The μ-SPE device, and extraction and derivatization conditions were optimized. The mechanism of extraction and derivatization was also discussed. While coupling to HPLC, the method detection limits were as low as 0.024-2.5 μg/L, and the method quantification limits were 0.081-7.6 μg/L with relative standard deviations (RSDs) in the range of 2.2-7.7%. Finally, this membrane protected μ-SPE-D-HPLC was successfully applied to the real sample analysis. In cosmetics analysis, aliphatic aldehydes were found and quantified in the range of 9.0-750.2 μg/kg, and the recoveries were in the range of 81.7-114.9% with RSDs less than 8.3% from toner and moisturizer samples. Meanwhile, aliphatic aldehydes were found and quantified in the range of 1.3-31.3 μg/kg, and the recoveries were in the range of 80.8-114.4% with RSDs less than 7.1% from fried food samples. Our results proved that only 5 min was needed for extraction and derivatization processes. Furthermore, the method detection limits of formaldehyde were an order of magnitude less than literature reports which reveal excellent selectivity of this membrane protected μ-SPE-D-HPLC method.