Single-step separation of major and rare ribonucleosides and deoxyribonucleosides by high-performance liquid cation-exchange chromatography for the determination of the purity of nucleic acid preparations

1977 ◽  
Vol 140 (3) ◽  
pp. 251-256 ◽  
Author(s):  
Hans-Joachim Breter ◽  
Gerhard Seibert ◽  
Rudolf K. Zahn
1998 ◽  
Vol 815 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Shin Ono ◽  
Tatsuo Funato ◽  
Yasuhiko Inoue ◽  
Tetsue Munechika ◽  
Toshiaki Yoshimura ◽  
...  

1990 ◽  
Vol 73 (4) ◽  
pp. 627-631
Author(s):  
Edgar C Nicolas ◽  
Kathleen A Pfender ◽  
Michael A Aoun ◽  
Jane E Hemmer

Abstract A fast and simple method for determination of taurine in Infant formulas has been developed. The sample preparation uses disposable ultrafiltration cartridges to remove protein and clarify the sample. Hydrolysis Is avoided, simplifying the procedure and increasing efficiency. One mL sample Is centrlfuged In a cartridge for 45 mln. The filtrate Is diluted with pH 2.2 citrate buffer and Injected into a high performance amino acid analyzer. A cation-exchange column (sodium phase) Is used with a single buffer eluant and an Isocratic chromatographic program. Colorimetrlc detection is performed following post-column nlnhydrln reaction. Chromatographic resolution from other nlnhydrln-posltive compounds is excellent. Average recoveries for 3 levels of spike for various products were 100-102%. Precision Is 1-3% RSD, depending on product. Linearity, specificity, and ruggedness are excellent. The method Is applicable to quality control testing of milk-based, soy-based, and prehydrolyzed proteinbased Infant formulas In the ready-to-use, concentrate, and powder forms. A variety of commercially available Infant formulas from different manufacturers were analyzed and all were found to contain taurine levels comparable to human milk. Some human milk and cow's milk samples were also analyzed and results compare well with literature values


1985 ◽  
Vol 31 (1) ◽  
pp. 114-117 ◽  
Author(s):  
R Flückiger ◽  
T Woodtli

Abstract As a consequence of nonideal chromatographic conditions, values for stable glycated hemoglobin (HbA1c) determined by cation-exchange chromatography in a commercial minicolumn system (y) or by "high-performance" liquid chromatography (x) differ markedly, yielding the regression line y = 0.82x + 0.6. With use of the protocol specified by the manufacturer, 20% of the HbA1c peak is not collected in the HbA1c fraction. Increasing the ionic strength of the eluting buffer by increasing the operating temperature to 28 degrees C increases the rate of elution from the minicolumn, making results of the two methods more closely comparable (y = 0.98x - 0.22). Because at a given pH the elution volume is determined primarily by the ionic strength, close limits on the composition of the eluting buffer are set by the temperature-dependence of its ionic strength. At a specified temperature and pH the position of a peak can be judged to within a volume of 1 mL if the conductivity of the eluent does not vary by more than +/- 0.05 mS.


2020 ◽  
Vol 35 (7) ◽  
pp. 1295-1299
Author(s):  
Lukas Miner ◽  
Diane Beauchemin

Cone corrosion by alkaline solutions with flow injection is prevented using cation-exchange chromatography coupled to inductively coupled plasma mass spectrometry.


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