Separator LiChrospher

Figure 16.4 displays the separation of the resins of B. carterii and B. serrata, their hydrodistillates, and three commercially available olibanum essential oils on a Merck LiChrospher plate in the mobile phase heptane-diethylether-formic acid (7 + 3 + 0.3 v/v/v) without chamber saturation after derivatization with anisaldehyde reagent. 

FIGURE 9.3 Typical SCX-RAM column separation profile peaks (a) represent physical exclusion by pore size. Trapped retained biomolecules are separated by a gradient in the second step (b). Conditions column—LiChrospher 60 XDS (S03/Diol), 25 x 4 mm I.D., flow rate— 0.5 mL/min, gradient from 0 to 1M NaCl in 20 mM KH2P04 pH 2.5, containing 5% ACN in 30 min. Sample 100 pL Human Hemofiltrate (3.7mg/mL), UV detection at 214 nm. 

Figure 4.3 Effect of particle diameter on plate height. (Reproduced from Lichrospher Lichroprep Sorbents Tailored for Cost Effective Chromatography, EM Separations, Gibbstown. With permission from Merck kGaA, Darmstadt, Germany, and EMD Chemicals, Inc.)...

Lichrospher Lichroprep Sorbents Tailored for Cost Effective Chromatography, EM Separations, Gibbstown. 

Mancinelli and colleagues (1999) reported the simultaneous determination of 3-4-methylenedioxymethamphetamine (MDMA), N-ethyl-3,4-methylenedioxyamphetamine (MDEA), methylenedioxyamphetamine (MDA), and N-methyl-l-(l,3-benzdioxol-5-yl)-2-butamine (MBDB) by RP-HPLC with fluorometric detection. The method required a 100 pi sample volume of serum, urine, or saliva separation was achieved on a LiChrospher lOORP-18 analytical column using an acetonitrile/water mobile phase (pH 11.4) set at a flow rate of 1 ml/min. The LLOQ and LLOD were 50 and 10 ng/ml respectively. 

For TRP-2 analysis, a reversed phase gradient method already developed (13) was slightly modified for our purpose. We used a Waters Alliance 2695 separations module equipped with a Waters 996 PDA detector and a CC125/3 Lichrospher 100-5 RP-18 column (Macherey und Nagel, Diiren, Germany) at 30°C and a flow rate of 0.5 mL/min. 

Fig. 2. Effect of silica pore structure on separation. Stationary phases are 10 LiChrospher SI 100, SI 00, SI 1000, and SI 4000 having 100, 500, 1000. and 4000 A mean pore diameter, respectively. Rowrate and inlet pressure are 5 ml/min and 125 bar, respectively. Sample components I, benzene 2. diphenyl 3, m-terphenyl 4, m-quaterphenyl 5, m ipiliiqiicphcnyl 6, m-sexiphenyl. (Cotiuesy of Merck AO.)...

FIG U RE 1.13 Gradient separation of polypeptides on silica rod column and particle-packed columns. Mobile phase velocity 4mm/s, gradient 5%-60% ACN in the presence of TFA, gradient time 5min, columns (a) silica rod column, (b) Capcellpak SG (5 pm), (c) LiChrospher WP 300 RP-18e (5 pm), (d) nonporous NPS-ODS-1 HPLC column (1.5pm) (e) polymer-based TSKgel Octadecyl-NPR (2.5pm). (Reprinted from Minakuchi, H. et al., J. Chromatogr. A, 828, 83, 1998. Copyright 1998, with permission from Elsevier.)... 

Herslof and Kindmark (105) report the use of the mass detector (light-scattering detector) in this sense. The column used (250 X 4.6-mm ID) was packed with LICHROSPHER RP 100 and thermostated at 22°C. The mass detector oven temperature was 40°C, and the inlet gas pressure was 15 psi. The mobile phase consisted of mixtures of acetonitrile, ethanol, and hexane. Gradients from 0 to 100 of ternary premixtures of the three solvents were used at a flow rate of 1 ml/ min. The sample was dissolved in hexane-isopropanol (1 1), and 12 /A were injected (approx. 150 fj.g total sample). The chromatogram of the standard mixture of TGs is shown in Fig. 35. The separations of soybean oil and a mixture of soybean and coconut oils illustrate the resolution of vegetable oils into TG species (Fig. 36). 

The enantiomers of pantoprazole were separated using HPLC at 40°C on Chiralcel OJ-R columns with 25% acetonitrile and 50 mM NaC104 (3 1 v/v) as the mobile phase [11]. Elution was performed at a flow rate of 0.5 mL/min, and detection was at 286 nm. Lichroprep PR-2 was used as a pre-column, and Lichrospher 100 RP-18 was used as a guard column. 

Benzoin acetate, methylben-zoin, Troger s base, tra/w-stilbene oxide and 1,1 -binaphthyl-2,2 -diol Aminopropyl silica gel (LiChrospher 1000, 5 pm) coated with helically chiral poly(diphenyl-2-pyridylmethyl methacrylate) (PDPM) Methanolic solution of ammonium acetate (2.5 mM, pH 4.5) 300 mm x 100 pm i.d. 200 mm effective length, chiral separation 163... 

P-adrenergic blocking agent and various enantiomers Vancomycin bonded on LiChrospher diol silica, 5 pm Methanol-acetonitrile-acetic acid-triethylamine (80-20 20-80 0.1-0.3 0.1-0.4) 355 mm x 75 pm i.d. 265 mm effective length, chiral separation... 

Shinozuka et al. [91] developed a sensitive method for the determination of four anthranilic acid derivatives (diclofenac sodium, aluminium flufenamate, mefenamic and tolfenamic acids) by HPLC procedure. The four drugs were converted into methylphthalimide (MPI) derivatives in a constant yield by reaction with /V-chloromethylphthalimide at 60°C for 30 min. The production of the MPI derivatives were confirmed by mass spectrometry. The MPI derivatives of the four drugs were separated by HPLC using a C-18 bonded phase LiChrospher RP-18 column (250 x 4 mm i.d.) with acetonitrile-water (80 20, v/v) as mobile phase. The flow rate was 0.8 mL/min. The UV absorbance was measured at 282 nm. The calibration curves of the MPI derivatives of the drugs were linear from 1.0 to 5.0 pg/rnL. The detection limits of the four drugs were 0.5-5 ng. The extraction procedure for the four anthranilic acid derivatives added in the plasma and urine was performed by using Extrelut 1 column. Yields of column extraction of 100 pL of plasma and urine samples (containing 0.5 pg of anthranilic acid derivatives) with 6 mL of ethyl acetate were 84-106%. 

The quinoxalinol derivatives of a-ketovaleric acid and ketovaleric acid (internal standard) were separated on a LiChrospher 100 RP-8 column (4 mm x 250 mm). The mobile phase was a 60 40 ratio of 0.35 Af ammonium acetate and acetonitrile. The eluate was monitored by fluorescence with the excitation and emission wavelengths set at 340 and 420 nm, respectively. 

Cohydrolysis [2-4] of npropyltrichlorosilane and 3-chloropropyltrichlorosilane in the molar ratio 6.5 1.5 yields 1 and by cohydrolysis of wpropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane in the molar ratio 7 1 2 can be obtained [5]. The compounds can be separated in semipreparative amounts with normal phase HPLC on a Merck Hibar RT 250-10 Si 60 LiChrospher (5 pm) column with whexane as eluent [5]. The retention times increase with the number of polar groups in the molecules (see Fig. 1). 

The compounds can be separated in semipreparative amounts with normal phase HPLC on a Merck Hibar RT 250-10 Si 60 LiChrospher (5 pm) column with a mixture of 50 vol % nhexane and 50 vol % CHCI3 as eluent. 

A recent development has resulted in HPTLC layers with spherical silica gels 511. These silica gels have a narrow particle size distribution with 6-8 pm of LiChrospher Si 60 F254S spread over glass plates at 0.2 mm thickness and on aluminium sheets at 0.1 mm thickness. At the same time spherical silica is possible with a. 3-5 pm spread on aluminium sheets to a thickness of 0.1 mm for the use of separated spots in Raman spectroscopy. Such plates are labelled HPTLC Aluminium sheets Si 60 FjsaS RAMAN. 

Fig. 2 Separation of 25 flavonoid standards (1—eriocitrin 2— neoeriocitrin 3—robinetin 4—narirutin 5—naringin 6— rutin 7— hesperidin 8—neohesperidin 9—isorhoifolin 10— rhoifolin 11—diosmin 12—neodiosmin 13—neoponcirin 14—quercetin 15— poncirin 16—luteolin 17—kaempferol 18—apigenin 19—isorhamnetin 20—diosmetin 21— rhamnetin 22—isosakuranetin 23— sinensetin 24—acacetin 25—tangeretin) using Cig Lichrospher 100, 250 x 4.0 mm, 5 pm, Merck gradient elution with 0.01 M phosphoric acid-methanol with flow rate of 0.6 mL/min at 40°C and detection at 285 nm. (From Ref. [8].)...

Pyka and Sliwiok separated six esters of nicotinic acids methyl nicotinate, ethyl nicotinate, isopropyl nicotinate, butyl nicotinate, hexyl nicotinate, and benzyl nicotinate by adsorption HPLC on a LiChrospher Si 60 column. The mixtures containing benzene and methanol in volume proportions (O-i-lO, 1h-9, 2h-8, 3h-7, 4-1-6, and 5-1-5) were used as the mobile phases. The (min) values of esters investigated have been correlated with the dipole moments (/imph) of the mobile phases apphed, with numerical values of one topological index from among those based on the distance matrix (A, W, °7J, B) or the... 

Pyka separated 16 PAHs (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo [a] anthracene, chrysene, benzo[/>]fluoranthene, benzo[fe]fluoranthene, benzo[a]py-rene, dibenzo[a,/z]anthracene, benzo[g,/i,i]perylene, and indeno[l,2,3-C(i]pyrene) according to the Environmental Protection Agency (EPA) by gradient HPLC on a LiChrospher PAH column using acetonitrile and water as mobile phases. Retention times fr (sec) of investigated PAHs were correlated with topological indices based on the adjacency matrix (M, 012) and the... 

Separation column 250 x 4 mm steel column packed with LiChrospher 60 RP select B, 5 pm (Merck)... 

As an example, Fig. 4.30 shows the separation of three pharmaceutical intermediates on LiChrospher RP-18 with a mobile phase composition of acetonitrile-water (80 20). Intermediate 1 elutes at 2.28 min while intermediates 3 and 2 co-elute at 3.16 min. Obviously, the separation problem is not solved and, thus, the mobile phase composition must be adjusted in subsequent batch runs with higher water fractions. 

Fig. 4.30 Separation with LiChrospher RP-18 with acetonitrile-water (80 20).

Table 4.10 Optimisation of an RP separation with LiChrospher RP 18 and different volume fractions of acetonitrile.

To check the selectivity with different chromatographic systems the separation with LiChrospher RP-18 is compared with the gradient separation with two different adsorbents. For LiChrospher RP-8 the separation with methanol-water is shown in... 

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