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Analytica 2016
September 28-30, 2016
Volume 7, Issue 5(Suppl) J Anal Bioanal Tech 2016
ISSN: 2155-9872 JABT, an open access journal
conferenceseries .com
September 28-30, 2016 Orlando, USA
7th International Conference and Exhibition on
Analytical & Bioanalytical Techniques
J Anal Bioanal Tech 2016, 7:5(Suppl)
PALMS: Parallel targeted/untargeted metabolome screening platform
Melnik A1, Da Silva R1, Hyde E1, Fernando Vergas1, Amina Bouslimani1, Ivan Protsyuk1, Theodore Alexandrov1 and Pieter C Dorrestein1,2
1University of California, USA
2European Molecular Biology Laboratory, Germany
3Steinbeis Center SCiLS Research, Germany
The human body contains about 10 microbes per each human cell if you do not consider red blood cells which are lacking
DNA. This means microbes significantly impact the chemistry in and on our body. Despite the role of microbial chemistry
on human health, we know very little about its chemistry, let alone quantitatively. One of the analytical methods that are sensitive
enough to measure microbial chemistry can be mass spectroscopy (MS). Here we introduce PALMS platform that is capable
of analyzing full sample profile using high accuracy Orbitrap instrument and quantify set of targeted metabolites using triple
quadrupole in a single LC run. Several hundred of fecal swabs samples from the American Gut project were tested and then
people were swabbed at several hundred locations for the creation of 3D quantitative maps. The system setup comprises of triple
quadrupole (qqq) and Orbitrap mass spectrometers connected in parallel to a single UHPLC system. Liquid connection was split
into equal ratio and directed into two MS which are equipped with identical HESI ion sources; tubing length maintained equal
in order to avoid any retention time (RT) differences between two MS. The data acquisition was triggered by UHPLC system
by mean of contact closure signal that is sent to both MS simultaneously. Data captured by Q Exactive recorder in untargeted
profiling mode with high resolution while quantitative data on defined targets were acquired by TSQ. We first evaluated our
system by screening of several hundreds of fecal swabs extracts received from American Gut project. For targeted quantification
we used mix of 200 standards containing microbial primary and secondary metabolites. We evaluated a distribution of the
standards in fecal samples by constructing a calibration curve with triple quadrupole data. Our results showed that even in
such high background as fecal matter we can quantify metabolites with relatively low error rate. By feeding mass list to triple
quadrupole we managed to achieve pictogram sensitivity at the same time acquiring a full molecular profile using Orbitrap.
By analyzing untargeted data we were able to putatively identify thousands of molecules using molecular networking while
quantification was performed for selectedmicrobial metabolites. Because inmolecular networking structurally similar molecules
clustered together we were able to relatively quantify analogs of the standards by extrapolating their concentrations. We then
used the platform for screening the microbial metabolites reside on human body. We constructed 3D chemical composition
maps of human skin surface. Highly accurate, untargeted data allowed for identification of some key microbial metabolites that
are distributed on the skin in the specific locations such as armpit and groin area. We then relatively quantified the metabolites as
some of our standards clustered with molecules of interest, which concentration was accurately measured by triple quadrupole.
Determining the quantitative information for key microbial metabolites grant us the possibility to calculate the amount of the
microbial cells that are primary producers and potentially assess the impact of them on our health.
Sub-2 μmC18 bound silicamonolith particles as HPLC stationary phase of high separation efficiency
Ashraf Ali Khan and Won Jo Cheong
Inha University, South Korea
S ub-2 μm porous silica monolith particles have been prepared successfully by sol-gel process followed by grinding and
calcinations at 550 oC. The particles were derivatized with a C18 ligand followed by end-capping with a mixture of
hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS). The resultant phase was packed in glass lined stainless steel
microcolumn is much better than that of commercial C-18 phase. This phase has shown some encouraging possibility for fast
analysis when packed in a short column. This study offers a promising vision towards commercialization of chromatographic
phases based on silica monolith particles.