Separator Purospher Star

The instrumental analysis for the identification of UV filters degradation products formed during the fungal treatment process was performed by means of HPLC coupled to tandem mass spectrometry using a hybrid quadrupole-time-of-flight mass spectrometer (HPLC-QqTOF-MS/MS). Chromatographic separation was achieved on a Hibar Purospher STAR HR R-18 ec. (50 mm x 2.0 mm, 5 pm, from Merck). In the optimized method, the mobile phase consisted of a mixture of HPLC grade water and acetonitrile, both with 0.15% formic acid. The injection volume was set to 10 pL and the mobile phase flow-rate to 0.3 mL/min. 

FIGURE 5.11 Gradient-elution reversed-phase separation of alkylbenzenes on a Purospher Star RP-18e, 3 am, column (30x4mm i.d.). (A) Non-adjusted linear gradients, 50%-100% acetonitrile in 3min at ImL/ min and at 3mL/min. (B) Adjusted linear gradients, 50%-100% acetonitrile in 3 min at ImL/min and 50%-100% acetonitrile in Imin at 3mL/min. Conditions 40°C, detection UV, 254 nm sample B—benzene, MB—toluene, EB—ethylbenzene, PB—propylbenzene, BB—butylbenzene, AB—amylbenzene, and HB—hexylbenzene. 

Figure 4.12 shows the separation of a pharmaceutical agent on an analytical alkyl-silica column (Purospher Star RP18e, 100mm long, internal diameter 4mm). The sample was dissolved in pure methanol and between 5 and 250 pi was injected, while the mobile phase consists of methanol and water (60 40 volumetric ratio). At small injection volumes no peak distortion is observed, but with 30 pi the chromatogram shows a distortion of the main peak and band splitting. A small part of the sample... 

Fig. 3 Gradient elution RP separation of alkylben-zenes with gradient times adjusted to varying flow rate of the mobile phase. Linear gradients, 50-100% acetonitrile in 3 min at 1 ml/min (top) and 50-100% acetonitrile in 1 min at 3 ml/min (bottom). Conditions Purospher Star RP-18e, 3 p,m, column (30 x 4 mm I.D.), 40°C, detection UV, 254 nm sample B, benzene MB, toluene EB, ethylbenzene PB, propylben-zene BB, butylbenzene AB, amylbenzene HB, hexylbenzene.

XTerra MS resembles Purospher Star, except in the polar groups of the latter. It is these that give rise to the good selectivity of Purospher in separating triphenylene/o-terphenyl. 

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