Ionic liquids improved reversed-phase HPLC on-line coupled with ICP-MS for selenium speciation

Metal and metalloid speciation in plants: Overview, instrumentation, approaches and commonly assessed elements

“…Unlike GC, derivatization to produce volatile compounds is not required. It is also more reproducible than CE [86]. Species alterations may still occur, however.…”

“…Trifluoroacetic acid (TFA) is a useful ion pairing reagent for IP-RPLC; achieving good separations, with the drawback of having long retention times and consequently, poor peak resolution [86]. HFBA, in comparison, is a stronger ionpairing reagent with better chromatographic resolution than TFA [86].…”

“…Room temperature ionic liquids (RTILs) have been found to be an attractive additive in HPLC columns in the analysis of selenium species, as found in studies such those conducted by Chen et al [86] which analysed Se species in yeast and clover, where good resolution of Se species could be achieved in 8 min.…”

A novel surface-confined glucaminium-based ionic liquid stationary phase for hydrophilic interaction/anion-exchange mixed-mode chromatography

“…[12,13]. In HPLC, ILs were applied in two ways, as mobile phase additives to mask the adverse effect of residual silanol groups [14][15][16] or being immobilized to the surface of supporting materials as stationary phases [17,18]. Qiu et al developed a number of imidazolium ionic liquid-based stationary phases [19][20][21][22][23], and found that ILs of different structures might exhibit reversed phase, ion-exchange or HILIC retention mechanism.…”

“…Separation conditions: mobile phases were 100 mM NH4FA (A) and ACN (B), with a gradient elution of 95%B maintained 6 min, linearly increased to 70%B from 6 to 12 min, maintained at 70%B from 12 to 17 min, to 95%B from 17 to 20 min, equilibration at 95%B to 35 min; flow rate at 0.4 mL/min; column temperature at 30 • C; DAD at 283 nm. Peaks: (1) 2 -hydroxychalcone,(2) prunetin, (3) chrysin, (4) hesperetin, (5) naringenin, (6) diosmetin, (7) daidzein,(8) apigenin, (9) (±)-dihydrokaempferol, (10) phloretin, (11) genistin, (12) daidzin,(13) phlorizindihydrate,(14) hesperidin, (15) naringin,(16) vitexin.…”