2 research outputs found
Smartphone-based colorimetric determination of sulfadiazine and sulfasalazine in pharmaceutical and veterinary formulations
<p>A novel, simple, accurate, and low-cost colorimetric device based on an Android smartphone was developed for sulfonamide determination. A software program was developed to be used for analyzing the samples. Various parameters for digital colorimetric detection were investigated and optimized, such as the volume of the sample drop, the type of sample holder, the distance from the mobile phone camera to the sample holder, and the effect of ambient light. From the optimized conditions, a calibration curve was created by the intensity of blue channel for sulfonamides for the concentration range of 0.5–2.5 µg mL<sup>−1</sup> with good linearity and a regression coefficient (<i>R</i><sup>2</sup>) of 0.996. The results obtained by the smartphone method were compared with a spectrophotometric procedure at the 95% confidence level (<i>n</i> = 3). Both methods correlated well with a regression coefficient (<i>R</i><sup>2</sup>) of 0.997. The limit of detection of both methods was equal to 0.11 µg mL<sup>−1</sup>. The developed smartphone system was successfully used for the determination of sulfonamides in pharmaceutical and veterinary formulations with recoveries of 102 and 98.7%, respectively. The developed method provides good accuracy (relative error <5%) and precision (relative standard deviation <7%) and offers simple, convenient, rapid, and inexpensive determination of sulfonamides.</p
Molecularly Imprinted Polymer-Decorated Magnetite Nanoparticles for Selective Sulfonamide Detection
Sulfonamides are known not only to
be antimicrobial drugs that
lead to antimicrobial resistance but also to be chemotherapeutic agents
that may be allergenic and potentially carcinogenic, which represents
a potentially hazardous compound once present in soil or water. Herein,
a hybrid material based on molecularly imprinted polymer (MIP)–decorated
magnetite nanoparticles for specific and label-free sulfonamide detection
is reported. The composite has been characterized using different
spectroscopic and imaging techniques. The magnetic properties of the
composite are used to separate, preconcentrate, and manipulate the
analyte which is selectively captured by the MIP onto the surface
of the composite. Screen printed electrodes have been employed to
monitor the impedance levels of the whole material, which is related
to the amount of the captured analyte, via electrochemical impedance
spectroscopy. This composite-based sensing system exhibits an extraordinary
limit of detection of 1 × 10<sup>–12</sup> mol L<sup>–1</sup> (2.8 × 10<sup>–4</sup> ppb) (<i>S</i>/<i>N</i> = 3), which is close to those obtained with liquid chromatography
and mass spectrometry, and it was demonstrated to screen sulfamethoxazole
in a complex matrix such as seawater, where according to the literature
sulfonamides content is minimum compared with other environmental
samples