Simple and Sensitive Paper-Based Device Coupling Electrochemical Sample Pretreatment and Colorimetric Detection.
We report the development of a simple, portable, low-cost, high-throughput visual colorimetric paper-based analytical device for the detection of procaine in seized cocaine samples. The interference of most common cutting agents found in cocaine samples was verified, and a novel electrochemical approach was used for sample pretreatment in order to increase the selectivity. Under the optimized experimental conditions, a linear analytical curve was obtained for procaine concentrations ranging from 5 to 60 μmol L(-1), with a detection limit of 0.9 μmol L(-1). The accuracy of the proposed method was evaluated using seized cocaine samples and an addition and recovery protocol.
Instituto de Química, Universidade de São Paulo , 05508-000, São Paulo, São Paulo, Brazil.
Thalita G
TG
Silva
Instituto de Química, Universidade de São Paulo , 05508-000, São Paulo, São Paulo, Brazil.
William R
WR
de Araujo
Instituto de Química, Universidade Federal de Uberlândia , 38400-902, Uberlândia, Minas Gerais, Brazil.
Rodrigo A A
RA
Muñoz
Instituto de Química, Universidade Federal de Uberlândia , 38400-902, Uberlândia, Minas Gerais, Brazil.
Eduardo M
EM
Richter
Unidade Técnico-Científica, Superintendência Regional do Departamento de Polícia Federal em MG , 38408-680, Uberlândia, Minas Gerais, Brazil.
Mário H P
MH
Santana
Instituto de Química, Universidade Federal de Goiás , Campus Samambaia, 74690-900 Goiânia, Goiás, Brazil.
Wendell K T
WK
Coltro
Instituto de Química, Universidade de São Paulo , 05508-000, São Paulo, São Paulo, Brazil.
Thiago R L C
TR
Paixão
D003042:Cocaine / Q000737:chemistry; D003124:Colorimetry / Q000295:instrumentation*; D004340:Drug Contamination; D055664:Electrochemical Techniques / Q000295:instrumentation*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D010209:Paper; D011343:Procaine / Q000032:analysis*
D011343:Procaine; D003042:Cocaine