Peptide identification and sequencing strategies by mass spectrometry have been very well-developed during the last 25 years after the soft ionization techniques have been introduced. When sequencing peptides with tandem mass spectrometry (MSn), peptides are cleaved at various locations off their backbones to generate fragment ions of different masses based on their amino acid sequences. The most common product ions are the b-, y-, and a-ions generated from the cleavage of amide bond (CO-NH) and the subsequent loss of CO from the b-ions to form a-ions. The resulting (MSn) spectra can be matched with a database or computed with an algorithm to get the original sequence of known or unknown peptides.
Mass spectrometry in connection with different separation techniques currently represents the main analytical approach for determination of residual pesticides in the Food & Agriculture industry. Traditionally, samples need to be collected and sent to a laboratory for analysis using techniques such as GC‐MS or HPLC‐MS, which are costly and time‐consuming. In addition, the conventional mass spectrometer usually requires laborious sample pre‐treatment, which does not allow for immediate in‐situ sample determination.
Beginning in the late 1990’s, opioid consumption has rapidly increased in the United States and Canada. Where access to pharmaceutical opioids is limited, heroin and counterfeit pills or powder are sold in the unregulated market. These powders and pills are of unknown content and may contain highly toxic opioids that could result in unintentional overdoses. Mass spectrometry has been demonstrated as a viable and cost effective way to screen opioids for toxic compounds.