Portable Infrared Laser Spectroscopy for On-site Mycotoxin Analysis

Abstract

Mycotoxins are toxic secondary metabolites of fungi that spoil food, and severely impact human health (e.g., causing cancer). Therefore, the rapid determination of mycotoxin contamination including deoxynivalenol and aflatoxin B1 in food and feed samples is of prime interest for commodity importers and processors. While chromatography-based techniques are well established in laboratory environments, only very few (i.e., mostly immunochemical) techniques exist enabling direct on-site analysis for traders and manufacturers. In this study, we present MYCOSPEC - an innovative approach for spectroscopic mycotoxin contamination analysis at EU regulatory limits for the first time utilizing mid-infrared tunable quantum cascade laser (QCL) spectroscopy. This analysis technique facilitates on-site mycotoxin analysis by combining QCL technology with GaAs/AlGaAs thin-film waveguides. Multivariate data mining strategies (i.e., principal component analysis) enabled the classification of deoxynivalenol-contaminated maize and wheat samples, and of aflatoxin B1 affected peanuts at EU regulatory limits of 1250 μg kg−1 and 8 μg kg−1, respectively.

Carbon source self-heating: ultrafast, energy-efficient and room temperature synthesis of highly fluorescent N, S-codoped carbon dots for quantitative detection of Fe(iii) ions in biological samples

“…38 The new absorption peaks at around 1740, 1650 and 1515 cm À1 were found to appear in the spectrum of CDs (Fig. 2c, curve b), which can be ascribed to the C]O, C]N and N-H groups, respectively, 26,39,40 verifying the oxidation and polymerization of TEPA. Additionally, another new absorption peak could also be observed at around 1120 cm À1 , which was associated with the stretching vibrations of the S]O bond derived from Na 2 S 2 O 8 , 41 and indicated the successful doping of sulphur into N, S-codoped CDs.…”

Gallium arsenide waveguides as a platform for direct mid-infrared vibrational spectroscopy

“…While the direct detection of mycotoxins may be limited with ATR-based IR sensors [30][31][32], the evaluation of matrix changes resulting from fungal activity after infection during growth, harvest, or storage scenarios may be promising. As previously shown, matrix changes are indeed correlated with the presence of mycotoxins, as shown via FT-IR-and QCL-based techniques with sensitivities at EU regulatory limits [33][34][35][36][37][38]. However, utilizing broadband spectra of selected mycotoxins along with smart extraction schemes may increase the utility of MIR monitoring systems, as shown for the example of AFB1.…”

Updated Overview of Infrared Spectroscopy Methods for Detecting Mycotoxins on Cereals (Corn, Wheat, and Barley)

“…The rate of proper cross-validation ranking varies between 79% and 85%, depending on the DON limit used to create the classes. Sieger et al [ 67 ] proposed a new on-site mycotoxin analysis by combining mid-infrared tunable quantum cascade laser spectroscopy (QCL) with GaAs/AlGaAs thin-film waveguides to classify deoxynivalenol-contaminated maize and wheat samples, and aflatoxin B 1 affected peanuts at European Union (EU) regulatory limits of 1250 μg kg −1 and 8 μg kg −1 , respectively. Very few techniques are available for on-site analysis.…”