Acclaim Mixed-Mode WAX

Figure 3.177 Separation of hydrophilic monocarboxylic acids with mixed-mode liquid chromatography. Separator column Acclaim Mixed-Mode WAX-1, 5 pm column dimensions 150 mm X 4.6 mm i.d. column temperature SOT eluent 25 mmol phosphate buffer,...

More than 5 years ago, two type IV mixed-mode columns that are based on an alkyl chain with terminal ion-exchange functional groups were commercialized under the trade name Acclaim Mixed-Mode WAX-1 [67] and Acclaim... 

Mixed-Mode WCX-1 [68] (Thermo Fisher Scientific, Waltham, MA, USA). The Acclaim Mixed-Mode WAX-1 column combines both hydrophobic and anion-exchange characteristics, which facilitates selectivity adjustment by changing mobile-phase ionic strength, pH, or organic modifier, either independently or concurrently. 

Figure 6.76 Selectivity adjustment by changing (a) ionic strength, (b) pH, or (c) organic solvent content in the mobile phase on Acclaim Mixed-Mode WAX-1 (5 pm). Column dimensions 150mmx4.6mm i.d. column temperature 30 °C eluent (a) MeCN/phosphate...

Because of its unique column chemistry, the Acclaim Mixed-Mode WAX-1 column provides complementary selectivity in comparison to a conventional reversed-phase column. During drug development a secondary LC method with significantiy different or even orthogonal selectivity is often required to complement the primary method, which typically uses a reversed-phase column. As shown in Figure 6.77, the Acclaim Mixed-Mode WAX-1 meets this requirement by providing a different elution order for aromatic acids that were taken as an... 

Acclaim Mixed-Mode WAX-1, MeCN/50 mmol/L phosphate buffer, pH 2.8 (20 80 v/v) flow rate 1 mlVmin detection UV (220 nm) injection volume 2 pU peaks 02 mg/L each of benzoic acid (1), phthalic acid (2), and 1,23-benzenetricarboxylic acid (3). 

Figure 6.78 Separation of various monocarboxylic acids of similar hydrophobicities on Acclaim Mixed-Mode WAX-1,5 pm. Column dimensions 150 mm x 4.6 mm i.d. column temperature 30 °C eluent 25 mmol/L phosphate buffer, pH 6 flow rate 0.8mL/min ...

The four Acclaim Mixed-Mode columns mentioned in Section 6.7.2 - Acclaim Mixed-Mode WAX-1, Acclaim Mixed-Mode WCX-1, Acclaim Trinity PI, and Acclaim Trinity P2 - can also be used under HILIC conditions. Acclaim Mixed-Mode WAX-1 and Acclaim Mixed-Mode WCX-1 are based on an alkyl chain with terminal ion-exchange functional groups. Because of this column chemistry, both columns offer multiple retention mechanisms, including ion exchange, reversed phase, and HILIC. As an example. Figure 7.7 demonstrates that in highly organic mobile phase. Acclaim Mixed-Mode WCX-1 can serve as a HILIC column. Hydrophilic analytes such as cytosine elute later than naphthalene as a hydrophobic neutral analyte. 

Acclaim HILIC-10 is similar to Acclaim Mixed-Mode WAX-1. This relatively new column is also based on high-purity spherical silica covalently modified with a proprietary hydrophilic layer. It is suited for use in a broad range of applications including the separation of hydrophilic drugs and their metabolites. Acclaim Mixed-Mode HILIC-1 is a stationary phase that combines both RP and HILIC properties. Unlike traditional RP or HILIC columns, this packing material features a long alkyl chain with a diol functionality at the terminal end. 

Figure 7.16 Separation of selected amino acids under HILIC conditions on Acclaim Mixed-Mode WAX-1. Column dimensions 150mmx4.16mm i.d., 5pm column temperature 30 °C eluent 75 25 (vAr) MeCN/25mmol/L...

Wang, L Henday, S.M., Liu, X., Tracy, M and Schnute, W.C. (2007) Simultaneous determination of melamine and cyanuric acid using LC-MS with the Acclaim Mixed-Mode WAX-1 column and mass spectrometric detection. Presentation at the 24th Montreux Symposium on LC/MS and Related Techniques, Hilton Head Island, SC, USA. 

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