Acetonitrile-water pressure test

Figure 3.79 Acetonitrile-water pressure test with a propionitrile porogen after activation of the inner wall of a PEEK column (polymerization at 65 °C over 17 h).

Figure 1.15 Fast analysis of a test mixture on a 10 cm x 4.6 mm I.D. column packed with 3 micrometer octa< ecylsilanized silica with a mobile phase flow rate of 3.4 mi. i.n (acetonitrile-water 7 3) and operating pressure of ca. 340 atmospheres. Peaks 1 uracil, 2 phenol, 3 - nitrobenzene, 4 - toluene, 5 -ethylbenzene, 6 - isopropylbenzene, and 7 - tert.-butylbenzene. (Reproduced with permission from ref. 222. Copyright Friedr. Vieweg 6 Sohn).

FIGURE 14.10 Comparison of benzene (1), naphthalene (2), and biphenyl (3) test probes eluted from a 3 cmx 75 (Xm inner diameter column packed with 1.8 flm C18 particles. Trace A was obtained at 1.2 /ll./min flow rate and trace B was obtained at 10,000 psi column head pressure (10 /il./min flow rate). Mobile phase was 60 40 acetonitrile water. 

Fig. 2.3. Chromatogram of 2 jil aliquois of a test mixture on a 100 x 2.1 mm column of 3.5 jcm SymmetryShield RPI8. Mobile phase A was 0.191 v/v formic acid in water and mobile phase B was 0.19 v/v formic acid in acetonitrile-water (95 5 v/v). Gradicnl time was 5 min and the flow rate was 1.5 ml/min. The temperature was 60°C. giving a starting pressure of ca. 300 bar (4350 psi). Detection was at 215 nm. Peak identities pyridine, quinine, ben/yl alcohol, phenol, nortriptyline, acetophenone. 3-methyl-4-nitrobenzoic acid, methyl salicylaldehyde, 4-chlorocinnamic acid and octanophenone.

Eluent delivery was provided by two model 510 high-pressure pumps coupled with automated gradient controller model 680 (Waters Chromatography Division, Millipore, MA, USA) and a model 7125 infection valve with a 20-(il loop from Rheodyne (Cotati, CA, USA) Stainless-steel columns (30 x 0.40 cm I.D.) packed from Tracer Analltica (Barcelona, Spain) with 10 un particle diameter Spherisorb ODS-2 (Merck, Darmstadt, FRG) were used. Four different LC mobile phase compositions were tested acetonitrile-water... 

Five naphthylisoquinoline alkaloids (dimers michellamine A, B, and C, and momomers korupensamine A and B) were separated on a Cjg column (positive ion electrospray MS, collision energy 25 eV collision pressure 2.5mTorr) using a complex 19-min 85/15 -> 60/40 water (0.1% TFA)/acetonitrile gradient [1171]. Test solution concentrations were 20ng/mL. 

FIGURE 16.8 High efficiency analysis of a test sample using five coupled Acquity 1.7-pm columns at near ambient temperature (40 C). Analysis conditions Total column length, 450 mm flow rate, 0.17 ml/min (system) pressure, 999 bar temperature, 40°C (Polaratherm) detection, 210 nm (20 Hz). Mobile phase 30/70 acetonitrile/water. Peak identification 1 = uracil, 2 = caffeine, 3 — pyridine, 4 — aniline, 5 — phenol, 6 — acetophenone, 7 = benzene. Source Reproduced with permission from 2006 Elsevier B.V. 

For isolation of the core peptides of PS I (CPI) the 66 kDa region was cut out after SDS-PAGE and was eluted from the gel by electroelution at 200 V for 8 h. The purity test of the obtained CPI was carried out by SDS-PAGE and by Western blot procedure. For analysis of lipids the PS I particles and the isolated CPI (PS I core peptides) were dialysed against water, precepitated with acetone, centrifuged at 5.000 x g for 20 min and washed two times with water. The sediments were extracted with boiling methanol and subsequently extracted with methanol/chloroform (1 2 v/v). For the HPLC analysis a lipid solution in methanol was used. The analysis was carried out with a RP-18 column with acetonitrile/water/phosphoric acid (85%) 60.39, 9 0, 1 (v/v/v). The column pressure was 5,5 bar and the flow-rate 0.5 ml/min. Detection of eluted lipids was obtained with a spectral-detector at 205 nm. 

Prohexadione-calcium standard solutions Dissolve 10 mg of prohexadione-calcium in 100mL of water to prepare a lOOmgL" solution. Transfer 100 p.L of this solution into a 30-mL test-tube, evaporate water to dryness under reduced pressure and to methylate prohexadione-calcium according to Section 6.3. Dissolve the product in acetonitrile to prepare the 0.05,0.2,0.4,0.6 and 0.8 mgL acetonitrile solutions. 

---