Eluant methanesulfonic acid

Fig. 4-70. Gradient elution of ethanolamines together with the six standard inorganic cations. - Separator column lonPac CS15 (2-mm) column temperature 40°C eluant methanesulfonic acid gradient 2 mmol/L isocratically for 14 min, then to 27 mmol/L in 16 min flow rate 0.3 mL/min detection suppressed conductivity injection volume ...

Fig. 9-152. Separation of inorganic cations in Diet Coke. — Separator column lonPac CS12 with guard eluant methanesulfonic acid gradient ...

Fig. 4-3. Simultaneous analysis of alkali metals, alkaline-earth metals, and ammonium on lonPac CS12. - Eluant 20mmol/L methanesulfonic acid flow rate 1 mL/min detection suppressed conductivity injection volume 25 pL solute concentrations 5 mg/L sodium (1), 5 mg/L ammonium (2), 5 mg/L potassium (3), 5 mg/L magnesium (4), and 10 mg/L calcium (5).

Fig. 4-4. Influence of acetonitrile on the retention of alkali- and alkaline-earth metals employing the lonPac CS12. — Eluant 10 mmol/L methanesulfonic acid — acetonitrile detection suppressed conductivity injection volume ...

Fig. 4-28. Isocratic separation of ethanolamines and alkali metals on lonPac CSll. - Eluant 35 mmol/L methanesulfonic acid flow rate 0.25 mL/min detection suppressed conductivity solute concentrations 0.25 mg/L lithium (1). 1 mg/L sodium (2).

Cation exchange chromatography with a methanesulfonic acid eluant is a much simpler alternative. For optimizing peak efficiencies, 1 % (v/v) methanol is added to the mobile phase. As an alternative to the lonPac CSIO, an OmniPac PCX-100 (see Section 6.7) can also be used. The latter one has very similar separation properties, but it is characterized by a lower hydrophobicity of the cation exchange functionality, which improves peak efficiency for choline and its derivatives even more. 

The CSRS-SC is a post-column electrolytic eluant suppressor package consisting of an Eluant Suppressor component (ES) and an Analyte Converter component (AC) that enables the suppressed conductivity detection of low-level ammonium and other amines. Figure 4-36 illustrates the ion movement through a CSRS-SC in detail. The eluant and the ammonium analyte (an example of the cation analytes) exit the analytical column as methanesulfonic acid (H+MSA ) and ammonium methanesulfonate (NH4+MSA ). In the Eluant Suppressor component, the majority of the eluant is suppressed to water and the analyte is converted to the base form, NH4+OH . However, a small amount of MSA reenters the eluant chamber near the exit, which converts the analyte back to the salt form, so that the analyte exits the Eluant Suppressor component as NH4+MSA in a background of dilute methanesulfonic add. In the Analyte Converter (AC) component, the NH4+ analyte cation is exchanged for a hydronium ion, resulting in conversion of the analyte to methanesulfonic acid, H+MSA . 

In 2001, a third type of suppressor — the Atlas Electrolytic Suppressor (AES) -was introduced. The Atlas suppressor is a continuously regenerated suppressor operated in the recycle mode and designed for optimal performance with conventional methanesulfonic acid (MSA) eluants. Able to suppress up to 25 mmol/L MSA at 1 mL/min, it can be used in combination with all weak acid cation exchangers except the high-capacity column lonPac CS16 (see Section 4.1.1). 

Fig. 4-46. Separation of ethylamines together with alkali- and alkaline-earth metals utilizing a step gradient. — Separator column lonPac CS14 eluant 9 mmol/L methanesulfonic acid + 5 mL/L acetonitrile for 6 min, then to 11 mmol/L methanesulfonic acid + 15 mL/L acetonitrile flow rate 1 mL/min injection...

Fig. 4 -64. Determination of biogenic amines together with common inorganic cations on lonPac CSl 7. - Separator column lonPac CS17 (2-mm) column temperature 40°C eluant 3 mmol/L methanesulfonic acid isocratically for 3.5 min, then linear gradient to 6 mmol/L methanesulfonic acid in 8.5 min, isocratically for 3 min, linear gradient to 40 mmol/L methanesulfonic acid in 5 min.

Fig. 5-7. Trace analysis of borate. -Separator column lonPac ICE-Borate eluant 2.5 mmol/L methanesulfonic acid +...

Fig. 6-69. Influence of the mobile phase ionic strength on the separation of ephedrines on OmniPac PCX-100. - Eluant (A) 80 mmol/L methanesulfonic acid - acetonitrile (80 20 v/v). (B) 20 mmol/L methanesulfonic acid + 50 mmol/L CsCi - acetonitrile...

Fig. 9-63. Cation analysis in a flue gas scrubber solution. -Separator column lonPac CS12 eluant 20 mmol/L methanesulfonic acid flow rate 1 mL/min detection suppressed conductivity injection 25 pL flue gas scrubber solution.

The separation of cations is usually carried out on lonPac CS12A with sulfuric acid or methanesulfonic acid as an eluant. For anion analysis, carbonate-selective anion exchangers such as lonPac AS12A or AS14 have proved to be suitable. Alternatively, gradient elution on lonPac AS 11 can be used. As a matter of principle, 2-mm columns are utilized in order to reach the required sensitivity. With a gas flow of 1 L/min, sampling times are between 10 and 40 minutes the preconcentrated volume ranges from 1 mL to 10 mL. Metal cations are rarely detected in clean room air because they are usually bound to particles. Because... 

Fig. 9-137. Separation of alkali- and alkaline-earth metals in various fruit juices and fruit purees. — Separator column lonPac CS12A eluant 20 mmol/L methanesulfonic acid flow rate 1 mL/min detection suppressed conductivity samples various fruit juices and fruit purees diluted 1 50 with de-ionized water peaks (1) sodium, (2) ammonium, (3) potassium, (4) magnesium, and (5) calcium (taken from [206]).

Fig. 9-183. Analysis of amyiamine in a pharmaceuticai drug. - Separator column lonPac CS14 eluant 50 mmol/L methanesulfonic acid - acetonitriie...

Fig. 9-184. Analysis of tert.-butylamine as a counter ion of a pharmaceutical drug. - Separator column lonPac CS14 eluant 10 mmol/L methanesulfonic acid - acetonitrile (99 1 v/v) flow rate 1 mL/min detection suppressed conductivity injection 20 pL drug solution (1 mg/mL BMS-188 494-04) solute concentration 10.6% (w/w) tert.-butylamine (1) (taken from [280]).

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