All News

Scored layers, sequential development, modifications of the development chamber, and a careful choice of standards produce better reliability in thin-layer chromatography analysis of urine for the diagnosis of mucopolysaccharidoses. In equivocal cases, repeating the procedure and varying the solvents will improve results.

Authors Chapman and Chen describe an enantiomer analysis method development strategy that uses a family of highly sulfated cyclodextrins to resolve a diverse array of compounds.

The authors' laboratory developed and validated an HPLC method to test for residual nonoxynol-9 on stainless steel, PTFE, and acrylic substrates.

This month's column looks at reproducibility and carryover problems associated with the development of a method used to verify analyst proficiency.

The first of a two-part series in which Majors examines the trends in column introductions at Pittcon 2001. He describes HPLC columns and packings for reversed-, normal-, and bonded-phase; ion-exchange; ion; size-exclusion; and large- and preparative-scale chromatography. He also looks at specialty HPLC columns.

John Hinshaw examines inlet problems and their possible remedies.

McDowall discusses how the needs of the regulated laboratory are changing the way chromatography data systems are designed and used.

This installment of "Directions in Discovery" describes experiments performed to optimize a standard quality-control method for protein purity evaluation using reducing capillary gel electrophoresis.

Hinshaw examines the reality of GC at high speeds, taking into account the potential for rapid separations an the speed limits imposed by the practicalities of instrumentation and other considerations.

Part II of this series describes different ways electrolytes can be buffered while maintaining compatibility with indirect detection.

A single-source reference for key chromatography terms.

Ettre discusses the celebration of the 50-year anniversary of the beginning of the universal application of GC and the investigation of complex samples and natural substances.

This article examines the role that multidimensional chromatography systems will play in high-throughput proteomics.

This month's column discusses the presence of sample peaks in chromatograms when only blanks are injected -- commonly called carryover. Most carryover problems can be eliminated by performing one or more of the approaches discussed in this column.

This first installment of a two-part series outlines the principles and approaches to indirect detection.

The FDA recently updated its 1987 guidelines for submitting samples and analytical data for method validation — a document that affects all analytical chemists working in the pharmacrutical industry. This article highlights the agency's recommendations of how to report and validate analytical data in all new drug applications.

In this month's installment of "LC Troubleshooting," John Dolan focuses on late-eluted peaks.

Norberto Guzman and Ron Majors look at three areas in which progress has been made in improving concentration limits of detection for CE and CE microchip techniques: preconcentration methods, detector enhancements, and derivatization methods to improve separation selectivity and to enhance detection.

Leslie Ettre outlines the transition from metal tubes to glass and finally to fused-silica tubing and discusses improvements in stationary-phase technology. He also mentions some trends for further improvement of capillary column GC.

The authors compare fast LC}MS with a flow injection analysis}MS method for effective quantitation in the high-throughput environment of today's drug discovery laboratories.

John Hinshaw examines the role of autosamplers as the first link in a GC separation.

Dolan discusses some of the pitfalls that users can encounter when adjusting a gradient-elution LC method.

An introduction to SQL, the language that creates, maintains, manipulates, and queries relational databases.

Ron Majors discusses stationary-phase developments such as molecular-imprint polymers and monolithic phases. He also examines column stability, temperature as a separation variable, ultrahigh-pressure LC, and retention mechanisms.

John Hinshaw looks at various means to heat GC columns.

The authors describe two tests performed using SPE. The first involved sterol isolation and cleanup of seed oils, and the second analyzed crude seed oils.

Ron Majors highlights presentation from the 24th International Symposium on High Performance Liquid Phase Separations and Related Techniques.

This column discusses the activities of a Russian pioneer of GC and outlines the principles of some of the techniques he developed.