Voltammetric Determination of Sulfonamides in Milk

Chem. Anal. (Warsaw), 49, 59 (2004)
Voltammetric Determination of Sulfonamides in Milk
by Maria Ren
Adam Mickiewicz University, Faculty of Chemistry,
ul. Grunwaldzka 6, 60–780 Poznañ
Key words:
differential-pulse voltammetry, sulfonamides, milk
A voltammetric method for determination of selected sulfonamides in milk has been proposed. Fundamental measurements were expected to provide information on the voltammetric
behaviour of sulfonamides and the conditions required for their determination have been
established. The effect of pH on the position and height of the sulfonamide reduction peak
recorded in Britton-Robinson buffer has been studied. Reduction peaks were observed at
the following potentials: –0.65 V, –0.72 V, –0.87 V for sulfadiazine (SDZ), sulfamerazine
SMR) and sulfamethazine (SMT), respectively and –0.66 V, –0.79 V, –0.91 V [pH = 3] for
sulfachloropyridazine (SCP). The investigated sulfonamides were determined using differential pulse voltammetry at the 10-7 mol L-1 concentration level (SDZ,SMR,SMT), and
10–8 mol L-1 for SCP. A procedure for determination of sulfonamides in the milk samples
spiked with their known amounts has been also proposed.
W pracy zaproponowano woltamperometryczn¹ metodê oznaczania wybranych sulfonamidów w mleku. Przeprowadzono podstawowe badania dotycz¹ce redukcji tych zwi¹zków
i warunków ich oznaczania. Zbadano wp³yw pH na po³o¿enie i wysokoœæ piku redukcji sulfonamidów w buforze Brittona Robinsona. Zaobserwowano piki redukcji przy potencja³ach:
–0.65 V, –0.72 V, –0.87 V odpowiednio dla sulfadiazyny, sulfamerazyny i sulfametazyny,
oraz –0.66 V, –0.79 V, –0.91 V [pH = 3] dla sulfachloropirydazyny. Badane sulfonamidy
mo¿na oznaczaæ metod¹ ró¿nicowej woltamperometrii pulsowej na poziomie stê¿eñ 10-7
mol L-1 w przypadku SDZ, SMR, SMT i 10-8 mol L-1 w przypadku SCP. Opracowano
metodykê oznaczenia sulfonamidów w próbkach mleka dotowanych znan¹ iloœci¹ sulfonamidów.
* Corresponding author. E-mail: [email protected]