Use of a pH-sensitive polymer in a microextraction and preconcentration method directly combined with high-performance liquid chromatography

1. González-Martín, R.
2. Pacheco-Fernández, I.
3. Maiti, B.
4. Ayala, J.H.
5. Afonso, A.M.
6. Díaz, D.D.
7. Pino, V.