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. 

Fig.4 Reconstructed SRM chromatograms obtained from the LC-ESI-MS/MS analysis of a 100 ng mL-1 standard mixture of estrogens (in the NI mode) and progestogens (in the PI mode). Column Purospher STAR RP-18e (125x2 mm, 5 pm, Merck). Mobile phase gradient acetonitrile/water. Flow rate 0.2 mL min-1...

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. 

L-arginine, metabo-lites/urine HPLCFL Column Purospher STAR RP-18e (250 X 4 mm, 5 pm) Mobile phase Solvent A di-sodium hydrogen phosphate/potassium hydrogen phosphate, pH 6.88 Solvent B ACN Solvent C MeOH (gradient elution) Detection Aex/em = 338/455 nm Extraction SPE/column Oasis MCX/elution 25 % NH3 water MeOH (10 40 50 v/v/v) LOD 0.05-198.5 pmol/ 20 pL injection LOQ 0.17-655.1 pmol/ 20 pL injection [66]... 

Enalapril, paracetamol, sotalol, dipyrone, vancomycin, captopril, fluconazole, cefazolin, metoprolol, aspirin, ticlopidine, prednisolone, propranolol, digoxin, sildenafil, furosemide, dexamethasone, carvedilol, ketoprofen, nifedipine, terbinafine, acenocoumarol, spironolactone/urine HPLC DAD Column LiChroCART Purospher STAR, RP-18e (250 x 4 mm, 5 pm) Mobile phase MeOH ACN 0.05 % TFA in water (gradient elution) Detection DAD X = 200 50 nm Adjusted to pH 7.0, protein precipitation LOD 0.01-1.44 pg/mL LOQ 0.04-4.35 pg/mL [72]... 

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. 4.12 Peak distortion due to injection of sample dissolved in pure methanol (Purospher Star RP18 methanol-water, 60 40).

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.

Wikberg et al. (2011) studied porous silicas (average pore diameter 6, 20, and 30 nm [Purospher STAR] with 5 m particles, and silica 10 nm [Merck] with 3 xm particles used as hydrophilic stationary phases in liquid chromatography) using the NMR spectra of bound water... 

Cocaine and its metabolites, amphetaminelike and lysergic compounds, Opioids, cannabinoids Filtration (0.45 m) Surrogate std (20 ng/L) On-line SPE (5 mL-h5 mL) Oasis HLB (cannabinoids) PLRPs (all rest) RP- HPLC Purospher Star RP18 (125 x2mm, 5 m) A AcN B H20 QqLIT (ESI +/-) 2 SRM 5-59 0 07-1.94 Postigo etal., 2008b... 

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. 

Zorbax Extend, Nucleosil HD, XTerra MS, and Purospher Star (Chem. 24). Hypercarb (Graphite), Nucleosil 50 (high coverage together with a small pore diameter), and Fluofix INW and lEW (short alkyl chains with fluorine atoms) are oddities . 

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