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Unrivaled End Capping Technology Efforts to eliminate solute-silanol

Targa HPLC columns are true to the Latin root of their name. TARGA, meaning “shield,” is precisely the effect the unique bonded phase has on the silica’s silanol surface.

Many HPLC column manufacturers illustrate the performance of their columns packed with iner t, base deacti-vated, “Type B silica” bonded phases by the chromatographic behavior of polar compounds such as pyridine. Performance claims can be misleading, however, when mobile phases are buffered to low pH or when they contain high percentages of organic solvent.

Favorable Kinetics at Aqueous or Organic Mobile Phase Extremes

The bulky moiety used for end capping TARGA C8 and C18 sorbents present other valuable selectivity characteristics in addition to the extreme iner tness to basic and acidic compounds. Long chain alkane bonded phases collapse under low organic phase conditions on most reverse phase HPLC columns causing poor reproducibility and slow reequilibra-tion. Fast gradients can be run on TARGA columns from initial 100% aqueous conditions with fast cycle times and very good run-to-run reproducibility. TARGA columns can also be run isocrat-ically in 100% aqueous conditions for carbohydrate analysis, or with only a few percent organic modifier to achieve selectivity on solutes that are retained under typical reverse phase conditions.

TARGA A P P L I C AT I ONS

Trace Catecholamine Analysis

In vivo microdialysis present a challenge to both instrumentation and column design, especially when depended upon as a tool for routine analysis. The chromatogram below illustrates rat hypothalamus microdialysis analysis for 5HT. Researchers repor t that the 100x2.1mm Higgins Analytical PEEK and titaniumTARGA C18 column operates routinely at 0.2 - 100 nM detection levels.

5HT Analysis of Rat Hypothalamus Dialysate

TARGA C18 5µm 100x2.1mm P/NTS-1021-C185

NaH2PO4 0.15M, OSA 0.74mM, EDTA 0.1mM pH 2.87 (orthophosphoric acid) 2% IPA

Instrumentation: Flux Rheos Isocratic Pump, In-line Solvent Degasser, Spark Holland Triathlon Autosampler, Antec INTRO EC Detector

Detection levels of 0.2 - 100 nM are routinely achieved.

TARGA Compared to a Competitor’s Hydophilic Column

150x4.6mm, 20% MeCN/water (unbuffered) 1mL/min

TARGA’s Superior Hydrophilic Reverse Phase Properties

Several manufacturers offer reverse phase column products with imbedded polar functionality intended to enhance the chromatography of hydrophilic compounds like those illustrated in the previous antibacterial example. Unfor tunately, most of these approaches introduce undesirable secondary effects that preclude their use with acidic or basic solutes unlike TARGA with its unique bonded phase.

Fat-Soluble Vitamin Assay

TARGA C18 5µm 100x2.1mm Par t Number TS-1021-C185 3% water in MeOH mobile phase 200µl/min, diode array detection

Analysis of Very Polar Antibacterials with a Highly Aqueous Mobile Phase

1.Vancomycin, 2. Cefotaxime, 3. Cefazolin

TARGA C18 100x2.1mmTS-1021-C185 Mobile Phase: 92%Water with 0.l% TFA pH2.5,

8% MeOH, DAD at 230nm

Unbuffered 20% MeCN/water

Anti-Hypertensives

TARGA C18 5µm 150x4.6mm Part Number TS-1546-C185 25% MeCN/20mM NaH 2 PO 4 pH3.2 1mL/min 260nm 1.Triamterene 2. Hydrochlorothiazide

Analgesics and Anti-Inflammatorys

TARGA C18 5µm 150x4.6mm Part Number TS-1546-C185 45% MeCN/20mM NaH 2 PO 4 pH3.2 1mL/min 260nm 1. Acetaminophen 2. Indoprofen 3. Naproxan 4. Indomethacin 5. Ibuprofen

A Popular Hydrophilic RP Column

TARGA C18 Column

Pyridine

Pyridine Phenol

Phenol