Plasma Pencil Atmospheric Mass Spectrometry Detection of Positive Ions from Micronutrients Emitted from Surfaces

Abstract

Analysis and detection of micronutrients is important for the reduction of the global burden of malnutrition-related disease. A relatively new technique, plasma pen atmospheric mass spectrometry (PPAMS) was applied in a comprehensive evaluation for rapid, simultaneous detection of the key micronutrients: zinc, iron, folate, vitamin A, and iodine. PPAMS was performed through the coupling of a low-temperature plasma pen to an atmospheric mass spectrometer (MS). The effectiveness of the PPAMS system was demonstrated through the generation of characteristic mass spectra and tandem mass spectra on neat micronutrient powders suspended on double sided tape. The analytical performance and ability to qualitatively separate out the nutrients from a complex biological solution and each other was then assessed through the application of PPAMS on a sample matrix of micronutrients in porcine plasma in which nutrient concentration is varied from high blood level concentrations (HBLCs) to low blood level concentrations (LBLCs). A multivariate software model, principal components analysis (PCA) was then used to qualitatively separate the fragments obtained by nutrient type. The resulting PCA scores plots of the positive ion spectra from each mixed sample showed excellent separation of HBLCs and LBLCs of single nutrients at the 95% confidence level.1 The associated PCA loadings plots showed that key loadings could be attributed to the expected micronutrient fragments. The PPAMS technique was successfully demonstrated and compared with traditional MS techniques: time-of-flight secondary ion mass spectrometry (ToF-SIMS) and electrospray ionization mass spectrometry (ESI-MS). Separation of the nutrients at concentrations relevant for human blood-based nutrient detection was possible in both ESI-MS and PPAMS. However, only PPAMS could detect the nutrients at physiological concentrations from porcine plasma. ToF-SIMS could detect the nutrients from plasma solution but required 5× to 1000× higher concentrations of folate, vitamin A, and iodine to achieve adequate separation of the micronutrients via PCA.

Quantification and remote detection of nitro explosives by helium plasma ionization mass spectrometry (HePI‐MS) on a modified atmospheric pressure source designed for electrospray ionization

“…To determine the detection limit of TNT on a HePI source coupled to a Waters-Micromass Quattro Ultima mass spectrometer Voltage and power LTP [33,34] probe ac, DBD He, Ar, N 2 , air (<0.4) N 30 ac, 2-5 kHz, 2.5-5 kV pp , <3 W DBDI [37][38][39] ac, DBD He, Ar, N 2 , air (0.05-0.2) Y À30 to +30 ac, 18-25 kHz, 3.5-4.5 kV pp , 5-30 W PADI [40] rf discharge He (>0.7) Y N/A rf, 13.56 MHz, 0.3 kV pp , <5 W DART [24,41] dc discharge He, N 2 (1) N 250-350 dc, +1-5 kV FA-APGD [31,32] dc discharge He (0.9-1.5) N 200 dc, À500 to À700 V MPDS [36] dc discharge He (0.28) Y ambient dc, À300 to 350 V PPAMS [42] ac DBD He (?) Y 30 ac, 2-5 kHz, 3-6 kV pp , <3 W HePI [43] dc discharge He (0.02-0.05) Y 30-400 dc, 1-5 kV operated in the negative ionization mode, first a series of TNT standard solutions were prepared.…”

Ambient DESI and LESA-MS Analysis of Proteins Adsorbed to a Biomaterial Surface Using In-Situ Surface Tryptic Digestion

“…Much work has been undertaken on this challenge with ultra-high vacuum analysis of proteins adsorbed to surfaces using time of flight secondary ion mass spectrometry (ToF-SIMS) [ 6 , 7 ] and matrix assisted laser desorption/ionization (MALDI) MS [ 8 , 9 ] with some success. The vacuum environment is, however, a significant obstacle to the analysis of the native surface protein state, and emerging ambient MS techniques offer great opportunities in this respect [ 10 ].…”

Generation and Applications of Plasma (An Academic Review)

“…Plasma pencil, which is also known as the Plasma plume is considered as the most important application for low pressure or non-equilibrium plasma. In the medical field, low-temperature plasma provides the no arcing risks and generates a low concentration of ozone because of plasma formation [37].…”