1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 DOI: 10.1002/elan.201700520 Batch Injection Analysis-Multiple Pulse Amperometric Fingerprint: A Simple Approach for Fast On-site Screening of Drugs Camila Garcia Cardozo, [a] Rafael Melo Cardoso, [b] Thiago Matheus Guimara ˜ es Selva, [c, d] Adriana Evaristo de Carvalho, [a] Wallans Torres Pio dos Santos, [e] Thiago Regis Longo Cesar Paixa ˜ o, [c] and Rodrigo Amorim Bezerra da Silva* [a, b] Abstract: In this work, the association of batch injection analysis with multiple pulse amperometric detection (BIA-MPA) is presented as a new approach to obtain drugs fingerprints. To illustrate the potential of this screening method, tablets containing sildenafil as the active substance were used. Here, a sequence of three potential pulses as a function of time (+ 1.3, + 1.6 and + 2.1 V) were applied on a boron-doped diamond elec- trode while reproducible injections were performed in a BIA cell (wall jet configuration). The chemical profile of the respective drug combined three ratios among the peak currents obtained in each amperogram: R 1 = ipa 1.6V /ipa 1.3V , R 2 = ipa 2.1V /ipa 1.6V ,R 3 = ipa 2.1V /ipa 1.3V . This simple protocol allowed discrimination between Viagra  (reference)/ge- neric and two smuggled tablets, as well as pure Viagra  from Viagra  adulterated with other electroactive com- pounds (caffeine, dipyrone, paracetamol and tadalafil). For comparison, screening of these samples was also performed using square wave voltammetry combined with a chemometric method (principal component analysis), in which was achieved similar discrimination by one or other strategy for the most of drugs. This new BIA-MPA fingerprinting combines desirable features in forensic science such as low cost, simplicity, high sample through- put (two drugs discerned in less than 30 s) and portability (screening at the place of the seizure). Keywords: Batch Injection Analysis (BIA) · Multiple Pulse Amperometry (MPA) · Fingerprinting · Screening · Sildenafil Citrate (Viagra) · Boron-Doped Diamond Electrode 1 Introduction The consumption of counterfeit pharmaceutical products has been growing substantially worldwide. Recent data (2013) estimates that the counterfeiting industry generates $75 billion of losses, increasing 13% annually (double that for legitimate pharmaceuticals) [1], becoming a trade more lucrative than that obtained from narcotics such as heroin and cocaine to organized crime [2]. The problem is more evident in countries with less regulation in the chain from production to sale, an absence of anti-counterfeiting legislation, weak penal sanctions and corruption [3]. Some reasons clients give for this illegal acquisition are that counterfeit drugs do not require a medical prescription and are easily acquired at lower prices in clandestine locations or on websites. However, this practice puts the health of patients at serious risk, because the authenticity and origin of these drugs are completely unknown. According to the World Health Organization (WHO), U.S. Food and Drug Administration (FDA) [4] and the Pharmaceutical Security Institute (PSI) [5], a counterfeit medicine is a product deliberately and fraudulently mislabelled with respect to identity and/or source, applied to branded and generic products [3]. Counterfeit drugs present fake labels or a discrepancy between the active pharmaceutical ingredient (API) information declared on the label and the real composition, including products containing: another API, no API, the correct API with the wrong dose, API with adulterants (such as dangerous impurities) and API from different sources. Other types acquired are smuggled drugs, originating from a clandes- tine process of importation. Despite smuggled medicines [a] C. Garcia Cardozo, A. Evaristo de Carvalho, R. Amorim Bezerra da Silva Faculdade de CiÞncias Exatas e Tecnologias, Universidade Federal da Grande Dourados, 79.804-970, Dourados, MS, Brazil E-mail: rabsilva@ufu.br rodamorimsilva@gmail.com [b] R. Melo Cardoso, R. Amorim Bezerra da Silva Instituto de Química, Universidade Federal de Uberlândia, 38400-902, Uberlândia, MG, Brazil [c] T. Matheus Guimar¼es Selva, T. Regis Longo Cesar Paix¼o Instituto de Química, Universidade de S¼o Paulo, 05508-000, S¼o Paulo, SP, Brazil [d] T. Matheus Guimar¼es Selva Instituto Federal de Educac ¸¼o, CiÞncia e Tecnologia de Per- nambuco, 50740-545, Recife, PE, Brazil [e] W. Torres Pio dos Santos Departamento de Farmµcia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 39100-000, Diamantina - MG, Brazil Supporting information for this article is available on the WWW under https://doi.org/10.1002/elan.201700520 Full Paper www.electroanalysis.wiley-vch.de  2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Electroanalysis 2017, 29, 2847 – 2854 2847