October 29th 2024
Manitoba Centre for Proteomics and Systems Biology scientists produced a new means of predicting peptide retention times for hydrophilic interaction liquid chromatography (HILIC) at acidic pH in formic-acid based eluents.
Obtaining More Consistent Results
January 1st 2006LCGC North America and its companion publication, LCGC Europe, are targeted for chromatographers in the United States and Europe, respectively. Sometimes I wonder whether or not the same types of problems are encountered by workers in liquid chromatography (LC) on both sides of the Atlantic. As I write this installment of "LC Troubleshooting," I have just completed three weeks of teaching LC short courses in Europe. I can assure you that the content of the questions I get in these classes is the same, no matter where they are taught. This column is based upon questions gleaned from the most recent courses - you can see that there are no national borders for LC problems.
Forensic Drug Screening by LC–MS Using Accurate Mass Measurement
November 1st 2005Because of progress in liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS) instrumentation, data processing and reporting, the measurement of compounds' accurate masses is becoming routine practice in screening analysis based on target databases. As such databases of monoisotopic masses can be easily updated with recent data from the literature; rapid characterization of new compounds and metabolites is possible without the need for primary reference standards. This approach has already been established in comprehensive toxicological urine screening and in analysis of drugs-of-abuse in seized street drug samples. Currently, a mass accuracy within 5 ppm can be routinely achieved, and confirmation via a numerical isotopic pattern match (SigmaFit) is provided by a new generation LC/TOF-MS instrument.
Evaluating Analytical Instrumentation Using the Golf Score Card Tool
September 1st 2005The use of a simple Excel-based "Golf Score Card" tool can facilitate assessments and instrument acquisistion decisions by collating and weighting the relative importance of the many criteria that impact the final purchase decision. The authors describe this process.
Key Factors in Sample Diluent Selection for HPLC Assays of Active Pharmaceutical Ingredients
July 1st 2005The authors explain why sample diluent is more than just a solubilizing agent and describe a systematic process for diluent selection when developing an HPLC assay of an active pharmaceeutical ingredient.
HPLC Analysis of Non-volatile Analytes Using Charged Aerosol Detection
A detection method based upon aerosol charging was examined for its applicability and performance with high performance liquid chromatography.
Adjusting Conditions for a Routine Reversed-Phase HPLC Assay, Part 2: Changing Separation Conditions
June 1st 2005In the last part of this series, the authors provide a technical review of the means for method adjustment and the pertinent regulations concerning the required validation of adjusted methods.
This month’s column provides an overview of green chemistry issues relating to preparative chiral SFC chromatography in support of preclinical development in the pharmaceutical industry.