4.
Simultaneous determination of erythromycin A in giant prawn and
tilapia in Mekong region by stripping square wave voltammetry
Nguyen
Phuoc Minh*, Tran Bich Lam, Nguyen Trong Giao
Department of Food Technology, Ho Chi Minh City University of
Technology, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City,
Vietnam E-mail: httk1983@gmail.com
Abstract:
Erythromycin A (EA) is now one
of antibiotics limited in seafood products in general and in
giant freshwater prawns (Macrobrachium rosenbergii) and
tilapia (Oreochromis niloticus) in particular while
exporting to the US, EU, Japan, Canada. There are many
methods used for analyzing this antibiotic in these aqua
species such as ELISA, HPLC, LC-MS/MS, GC-MS, etc. A new
sensitive analytical approach for determination of
erythromycin A using stripping square wave voltammetry at
the slowly dropping mercury electrode was primarily
developed and validated to quantify this antibiotic with
simple and short time analysis, not too pure analytical
solutions, not high price equipments. Electrochemical
signals were measured at potential wave -1430 mV. The
optimal experimental parameters for the method were:
supporting electrolyte ammonium acetate 0.1 M, pH 8.0, the
solvents for dissolving erythromycin standard: acetonitril,
Vstart = -400 mV, Vstop = -1700 mV, Vstep = 6 mV, Vpulse =
40 mV, Tdrop = 5000 ms , Velctrolise = -1100 mV,
Telectrolise = 5 s. The method showed high recovery (85.07 ÷
96.50 %), high sensitivity (lower limit of detection, LoD =
0.57 µg.kg-1 in giant prawn and LoD = 0.52 µg.kg-1 in
tilapia) and high precision (RSD 0.91 ÷ 2.1 %) as well as
excellent linearity (r2adjusted ≥ 0.99999).
Keywords: Erythromycin A; giant freshwater prawn;
tilapia; stripping square wave voltammetry; dropping mercury
electrode.
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