# A Review: Sample Preparation and Chromatographic Technologies for Detection of Aflatoxins in Foods
## 3 Chromatography
### Liquid Chromatography and Mass Spectrometry
#### 3.3.2 LC-MS for Quantitative Analysis
Compared to LC-FLD methods, the LC-MS/MS method not only generated comparable results concerning aflatoxin B\({}_{1}\) in FAPAs proficiency test samples but also quantitated other mycotoxins in one analysis. [PERSON] et al. [283] proposed and evaluated a generic extraction approach using water-acetonitrile-1% formic acid as an extraction solvent to analyze 136 pesticides, 36 natural toxins (including aflat) and 86 veterinary drugs in foods and feeds. After extraction, no further clean-up was performed, extracts were directly injected into an LC-QQQ. Recoveries for 80% of the analytes were between 70% and 120% with RSDs \(<10\%\). Matrix effects were minimized by using matrix-matched calibration standards and a small injection volume, 5 uL. It is clear that with reasonable performance criteria, LC-MS-based multianalyte methods could significantly improve operation efficiency, replacing many matrix- and compound-dependent single mycotoxin methods [284; 285; 241]. The intended use of multimycotoxin methods should be clearly defined so that a practical balance between method performance and number of target mycotoxins could be reached. For example, [PERSON] et al. [55] developed a stable isotope dilution LC-MS/MS method to analyze aflat, fumonisins, ochratoxin A, deoxynivalenol, HT-2/T-2 toxin and zearalenone in foods. As the method was intended for the FDA regulatory program, only FDA regulated mycotoxins (e.g., aflat) and a few mycotoxins of health significance (zearalenone, HT-2/T-2 toxins) are included. Each mycotoxin was quantitated using a \({}^{13}\)C-IS and the method could identify and quantitate these mycotoxins at concentrations ranging from 1.0 to 1000 ng/g in peanut butter, wheat flour and corn. The majority of recoveries ranged from 80 to 120% with RSDs \(<20\%\). Greater than 90% of the average recoveries were in the range of 90-110%, with repeatability RSD\({}_{\text{r}}\) (within laboratory) \(<10\%\) and reproducibility RSD\({}_{\text{R}}\) (among laboratory) \(<15\%\). Although such an approach would not be realistic for the quantification of 191 mycotoxins [279] or 295 bacterial and fungal metabolites in foods [284], a similar platform may be utilized for screening mycotoxin occurrence in different matrices. To date, the majority of LC-MS-based mycotoxin methods have been developed using LC-QQQ, however, LC-high resolution mass spectrometry (HRMS; e.g., LC-Orbitrap-MS and LC-Q-time of flight-MS) has gradually attracted attention [285; 286]. LC-HRMS offers the acquisition of high resolution full scan data with accurate _m/z_ and the option of targeted or non-targeted sample acquisition with retrospective data analysis. Although it is still a niche application, LC-HRMS has been evolving rapidly in the field of mycotoxin analysis and provides a powerful tool to screen for aflat and other mycotoxins in food and feed products. Early HRMS applications were stymied by the lack of impactful understanding and agreement among mycotoxin researchers regarding the role of LC-HRMS in mycotoxin analysis. The lack of software tools and identification criteria created severe technical impediments to the application of LC-HRMS, but rapid improvements of hardware (e.g., sensitivity, resolution power and data acquisition rate), data mining software and data storage systems supported by identification criteria guidance will likely facilitate the implementation of LC-HRMS moving forward [282; 287; 288]. Like LC-QQQ, LC-HRMS, especially LC-Orbitrap and LC-Q-Orbitrap MS is commonly used for multimycotoxin and multianalyte analysis. Due to limited use of LC-TOF in mycotoxin research, very few studies use LC-TOF or LC-Q-TOF for aflatoxin analysis. [PERSON] et al. [289] used a LC-Q-TOF and studied fragmentation patterns of aflat under different collision energies. No quantitative analysis was performed. In an early LC-HRMS study, [PERSON] et al. [290] coupled a direct analysis in real time (DART) ionization source with an Orbitrap MS for the quantitative analysis of multiple mycotoxins in wheat and maize.