Shed­ding Light
on the
dark me­ta­bo­lo­me

The term dark me­ta­bo­lo­me de­scri­bes the lar­ge num­ber of un­an­no­ta­ted fea­tures in un­t­ar­ge­ted LC-MS da­ta­sets. Part of this chall­enge is bio­lo­gi­cal com­ple­xi­ty. Part of it is io­niza­ti­on bias.

Io­niza­ti­on de­ter­mi­nes what be­co­mes vi­si­ble.

Com­ple­men­ta­ry
Io­niza­ti­on

SICRIT® is a gas-pha­­se io­niza­ti­on tech­ni­que that can be di­rect­ly cou­pled to LC and SFC via an in­te­gra­ted va­po­riza­ti­on mo­du­le and it is ful­ly com­pa­ti­ble with es­tab­lished LC-MS work­flows.

A peer re­view­ed JASMS 2024 stu­dy com­pared LC-ESI-MS and LC-SICRIT®-MS in mi­cro­bi­al me­ta­bo­lo­mics and show­ed: The com­bi­ned ap­proach in­creased over­all fea­ture co­vera­ge.

The fi­gu­re shows the sta­tis­ti­cal com­pa­ri­son bet­ween SICRIT® and ESI V. fi­sche­ri data. Venn dia­gramm with the num­ber of fea­tures de­tec­ted in each source for all bio­lo­gi­cal con­di­ti­ons com­bi­ned [1].

V. fi­sche­ri fat­ty acyl main class an­no­ta­ti­on counts by io­niza­ti­on source. The stri­ped bars cor­re­spond to ESI an­no­ta­ti­on counts, and the so­lid bars cor­re­spond to SICRIT an­no­ta­ti­on counts. All an­no­ta­ti­ons are MS2 le­vel and were ob­tai­ned from Bruker’s Me­ta­b­os­cape soft­ware [2].

MS2 li­pid an­no­ta­ti­ons show­ed class de­pen­dent dif­fe­ren­ces bet­ween ion sources.

Dif­fe­rent io­niza­ti­on me­cha­nisms em­pha­si­ze dif­fe­rent re­gi­ons of che­mi­cal space.

Evi­dence

Hy­dro­pho­bic me­ta­boli­tes

Re­lia­ble de­tec­tion of all ca­li­bra­ti­on points for de­ri­va­ti­zed Vit­amin K1 and Vit­amin D3 de­mons­tra­tes ro­bust io­niza­ti­on of li­pophi­lic com­pounds.

Ca­li­bra­ti­on rows for Vit. K1 and D3 and EIC of lo­west ca­li­brant

Per­fluo­ri­na­ted com­pounds

SICRIT® io­ni­zes PFC com­pounds not ac­ces­si­ble by ESI or APCI un­der com­pa­ra­ble con­di­ti­ons.

Io­niza­ti­on of 2-(perfluorodecyl)Ethanol and 1H-Per­fluo­ro­de­ca­ne

Small or­ga­nic acids

LC-SICRIT®-MS pro­vi­des clean ne­ga­ti­ve mode de­tec­tion of ma­leic acid and py­ru­vic acid via simp­le [M‑H]- de­pro­to­na­ti­on.

EICs for Ma­leic Acid and Py­ru­vic Acid at 4500 ng/ml and 5000 ng/ml re­spec­tively

Prac­ti­cal
Va­lue

SICRIT® does not re­place ESI. It pro­vi­des an or­tho­go­nal io­niza­ti­on per­spec­ti­ve.

Ex­pan­ding che­mi­cal ac­ces­si­bi­li­ty re­du­ces io­niza­ti­on bias and broa­dens me­ta­bo­lo­mic co­vera­ge.

In the con­text of the dark me­ta­bo­lo­me de­ba­te, shed­ding light starts with un­der­stan­ding what io­niza­ti­on makes vi­si­ble.

Dis­cuss how com­ple­men­ta­ry io­niza­ti­on can ex­pand your LC-MS co­vera­ge!

Cont­act Us