Mass spectrometry is the most specific technique for the detection and identification of organic and inorganic compounds. It is able to provide molecular weight information as well as a wealth of structural details that together give a unique fingerprint for each sample. It is used widely in analytical laboratories for academic research, industrial product development, and regulatory compliance with particular importance in proteomics, drug discovery, environmental monitoring, food regulation, and forensic and homeland security. Due to these characteristics, MS-based analytical methods are showing an increasing interest in the scientific community, where the identification of unknown compounds in complex matrices represents a key parameter. The advent of ambient MS technology paved the way for the development of a great variety of applications and innovations: the challenge of analyzing samples in their native state encouraged the development of new ion sources like desorption electrospray ionization (DESI), direct analysis in real time (DART), or paper spray ionization (PSI). Miniaturized mass spectrometers have been recently introduced to improve portability and accessibility in order to promote in-field and real-time analyses. Novel materials and new instrumental configurations are under study to enhance the performance of different ion sources; additional dimension for separation using ion mobility has been proposed for the analyses of complex mixtures. Safety issues can be identified at the early stages through nontargeted monitoring technologies. Furthermore, the variety of fragmentation strategies that can be combined in new instrumentation overall enhances work in the OMICS fields, particularly proteomics and metabolomics. Mass spectrometric imaging is another emerging powerful analytical technique that has been applied to perform parallel analyses of multiple molecules in complex samples without labeling, thus providing a distinct advantage over preexisting methods for label-free and simultaneous detection of drugs and metabolites. Although MS-based methods are getting progressively more powerful, more reliable, and easily available, the main drawbacks are still related to sample complexity and preparation, mass accuracy, and the need of high-throughput and screening analyses when a great number of samples have to be analyzed.

The aim of the proposed special issue is to cover the aspects regarding emerging features of MS-based techniques. Innovative studies on advances in MS are welcome: submission of papers dealing with the development of prototypes, new instrumental configurations, and MS-based methods, in which new approaches of environmental, food, clinical, or forensic concern are described, is encouraged. The role of MS innovations should be clearly pointed out.

Potential topics include but are not limited to the following:

• New materials for MS-based analyses
• New MS instrumentation and approaches
• MS-based analytical methods for forensic applications
• MS-based methods for biomarker disease/drug discovery
• MS-based methods for food security and food safety
• MS-based methods for environmental analysis
• MS-based methods in the cultural heritage field
• Ambient MS
• Imaging MS