USF inventors have coupled an ultrasonic piezo that is originally designed as a room humidifier, termed ultrasonic nebulizer, with an APCI source to invent a novel ionization source. The ultrasonic nebulizer is a high-performance ionization source, while coupling with APCI significantly improves ion signals. The invention was experimentally proven to yield the highest survival yield (SY) compared to the state-of-the-art, and be robust against temperature changes on the inlet capillary. The direct mass spectrometry detection of a variety of antibiotics in the same test sample show that detection limits for all tested antibiotics are less than half compared to that of the state-of-the-art. This invention has numerous other diagnostic mass spectrometry applications, such as dry blood spot analysis.
Survival Yield as a Function of Temperature with Various Ionization Methods