Waters PIC Reagents - Manual

[ Care and Use ManUal ]
PIC Reagents 1
[ Care and Use ManUal ]
Contents
I. IntroduCtIon
II. PaIred-Ion ChromatograPhy
III. seleCtIng the reagent for your seParatIon
IV. usIng and storIng Waters PIC reagents
V. orderIng InformatIon
VI. Warranty/serVICe InformatIon
I. IntroduCtIon
Waters PIC ® reagents allow simultaneous separation of acids, bases,
amphoteric, and neutral compounds on a reversed-phase column
by paired-ion chromatography (PIC). Separation of ionic species in
complex samples is easy with PIC reagents.
Use PIC A for separation of acids.
Use the PIC B series to separate bases.
Use Reagent D4 as a mobile phase modifier when separating basic
pharmaceutical compounds to improve peak shape and reduce reten-
tion times.
Low-UV PIC reagents are also available, for use in separations of
compounds that have chromophores below 240 nm.
Table 1. PIC Reagents
PIC reagents
II. PaIred-Ion ChromatograPhy
Paired-ion chromatography is a technique for performing ion-
exchange separations on a reversed-phase column. Hydrophobic
paired-ion reagents added to the mobile phase are adsorbed onto the
stationary phase. There they enhance the interaction of oppositely
charged sample components with the stationary phase. A paired-ion
reagent:
• Increases the retention of oppositely charged solutes
• Decreases the retention of equally charged solutes
• Does not affect the retention of uncharged solutes
For a detailed description of the retention mechanism, see B.A.
Bidlingmeyer, S.N. Deming, W.P. Price, B. Sachok and M. Petrusek,
“Retention Mechanism for Reversed-Phase Ion-Pair Liquid Chromatog-
raphy”, Journal of Chromatography 186 (1979), 419-434.
III. seleCtIng the reagent for your seParatIon
Use PIC A Reagent to increase the retention of acids. Use the PIC B
Reagent to increase the retention of bases. Which of the four B
reagents to use depends upon your sample. Retention increases with
increasing reagent chain length. It is usually best to start with PIC B7.
If more retention is needed, use PIC B8. If less is needed, use PIC B5
or B6.
You can also use the concentration of organic modifier in your mobile
phase to manipulate the retention of all compounds, including neutral
compounds.
Reagent Compound
PIC A Tetrabutylammonium phosphate
Low UV PIC A Tetrabutylammonium hydrogen sulfate
PIC B5 Pentane sulfonic acid
PIC B6 Hexane sulfonic acid
PIC B7 Heptane sulfonic acid
PIC B8 Octane sulfonic acid
Reagent D4 Dibutylammonium phosphate