Conversion Parameter between pH Scales (swpH and sspH) in Acetonitrile/Water Mix
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- 作者：Leonardo G. Gagliardi ; Cecilia B. Castells ; Clara Rà ; fols ; Martí ; Rosé ; s ; Elisabeth Bosch
- 刊名：Analytical Chemistry
- 出版年：2007
- 出版时间：April 15, 2007
- 年：2007
- 卷：79
- 期：8
- 页码：3180 - 3187
- 全文大小：123K
- 年卷期：v.79,no.8(April 15, 2007)
- ISSN：1520-6882
文摘
The 
in acetonitrile/water mixtures at different temperatures cannot be directly measured because of the lackof calibration buffers in these hydroorganic media at mosttemperatures different from 25 
C. In this paper, the 
parameter has been determined for acetonitrile/watermixtures from 0 up to 90% acetonitrile at differenttemperatures from 15 to 60 C, and the values were fittedto a very simple simultaneous function of composition andtemperature. The values allow conversion of the 
scale (pH measured in acetonitrile/water with electrodescalibrated in water) to the 
scale (pH measured inacetonitrile/water with electrodes calibrated in the sameacetonitrile/water mixture). The practical determinationof 
is direct because the calibration of the electrodesis carried out with commercial aqueous standard buffers.Thus, the 
value of any buffered acetonitrile/watermobile phase used in reversed-phase liquid chromatography, which is directly related to the ionized fraction ofanalyte and, therefore, to its average retention, can beeasily known at any temperature from the measured 
and the corresponding value.
in acetonitrile/water mixtures at different temperatures cannot be directly measured because of the lackof calibration buffers in these hydroorganic media at mosttemperatures different from 25 C. In this paper, the parameter has been determined for acetonitrile/watermixtures from 0 up to 90% acetonitrile at differenttemperatures from 15 to 60 C, and the values were fittedto a very simple simultaneous function of composition andtemperature. The values allow conversion of the scale (pH measured in acetonitrile/water with electrodescalibrated in water) to the scale (pH measured inacetonitrile/water with electrodes calibrated in the sameacetonitrile/water mixture). The practical determinationof is direct because the calibration of the electrodesis carried out with commercial aqueous standard buffers.Thus, the value of any buffered acetonitrile/watermobile phase used in reversed-phase liquid chromatography, which is directly related to the ionized fraction ofanalyte and, therefore, to its average retention, can beeasily known at any temperature from the measured and the corresponding value.