简介

In recent years, substantial developments have taken place in the field of  mass spectrometry, enabling the introduction of a number of novel ambient  desorption ionization techniques such as direct analysis in real time (DART®),  desorption electrospray ionization (DESI),3 surface desorption atmospheric  pressure chemical ionization (DAPCI) and atmospheric solids analysis probe  (ASAP™). These novel ion sources are characterized by remarkably high throughput  of analyses which can be carried out under ambient conditions without  (chromatographic) separation of sample components prior to desorption/ionization  or the need for complicated and time demanding sample pre-treatment procedures.  The DART technology employed in this study relies upon fundamental principles of  atmospheric pressure chemical ionization (APCI). Excited-state helium atoms  produce reactive species for analyte ionization.Numerous applications of the  DART ion source coupled to various types of mass spectrometers have been  reported. DART found its use in many areas of analytical chemistry as a tool for  rapid qualitative analysis of numerous compounds. Due to the relatively high  signal fluctuation of ion intensities obtained by repeated DART measurements, an  internal standard usually has to be employed for compensation during  quantitative analysis. However, implementation of Vapur® gas ion separator and  automatic sampling systems were reported to significantly improve the  repeatability for some analytes.

实验仪器

Q Exactive台式FT轨道阱质谱仪

结论

The results presented in this application note demonstrate the feasibility of  DART ionization source in combination with Exactive mass spectrometer for the  rapid detection and quantification of various food contaminants, including set  of priority mycotoxins and melamine selected as an example. Comparable trueness  of generated results was achieved by applying isotope dilution-based  quantification and matrix-matched calibration to compensate for signal  suppression and other matrix effects that unavoidably occur during direct  analysis of real matrix samples. The major advantages of the combination of  ambient ionization technique with Exactive mass spectrometry are the simplicity  of operation, day-to-day robustness and broad application range. In addition,  ultra highresolution provided by Exactive mass analyzer helps to solve some of  the problems caused by isobaric interferences from matrix components. The choice  of ultra high-resolution mass spectrometer such as Exactive is one of the key  requirements when considering the application of DART ionization as a reliable  tool in the food laboratory.