USB-Powered Coated Blade Spray Ion Source for On-Site Testing Using Transportable Mass Spectrometry

On-site testing in food analysis using mass spectrometry (MS) requires miniaturization of vacuum systems, mass analyzers, sample cleanup, and ionization sources. In this study, a simple coated blade spray (CBS) ion source was developed that enables high voltage generation on the blade by ubiquitous certified (micro-)USB On-The-Go devices like smartphones, tablets, and power banks. CBS is capable of performing both analyte enrichment by solid-phase microextraction (SPME) material coated on the metal substrate and direct-spray ionization. The USB-CBS device was used on two different MS systems, a transportable single-quadrupole and a benchtop triple-quadrupole tandem MS. Various characteristics of the USB-CBS device, including high voltage generation and angular positioning, were studied. The potential of the newly developed device for food safety applications is demonstrated by banned and regulated veterinary drugs such as β-agonists and sulfonamide antibiotics, covering a wide range of molecular weights and polarities. The results highlight the potential of the developed, simplified, inexpensive (less than 10 USD), and universal vendor-independent USB-powered CBS ion source coupled with MS(/MS) systems for semiquantitative applications, in laboratories, and in future on-site food quality and safety testing. Apart from that, most likely on-site environmental, biomedical, and forensic testing will also benefit from this USB-CBS instrumental development that is compatible with any atmospheric inlet MS system.