HPLC and GC Articles

A wide variety of antigens can be used as vaccine therapeutics. The first vaccines used the weakened live or killed microorganisms. As time progressed, protection could be acquired by using parts of a microorganism such as proteins or polysaccharides.

In 1997, in an article that appeared in what then was LCGC International (now LCGC Europe), I departed from my usual technical writing, which up to then had been primarily for peer review. The LCGC editor had requested help recognizing the publication's 10th anniversary.

Each week I get emails from various readers with questions or problems (see contact information at the end of this column). I enjoy most of these and often they give me fodder for one of these "LC Troubleshooting" columns.

Cymoxanil (2-cyano-N-[(ethylamino) carbonyl]-2-(methoxyimino) acetamide) is the active ingredient in a number of pesticides manufactured by Dupont, for the control of various fungal diseases in crops and plants. It is used mainly for late blight potatoes, but also is applied to grapes, tomatoes, cucumbers, and leafy vegetables.

As establishment of the sequence of the human genome neared completion, it was recognized that the next task for the biological science community would be to characterize the working products of the genome, which are largely proteins.

In the vast majority of previous "Validation Viewpoint" columns, we have emphasized low molecular weight (MW), conventional, synthetic, single molecule (or enantiomers) pharmaceuticals. At times, we also have devoted columns more toward biotechnology-derived products or impurities, also known as biopharmaceuticals (1–4).

In the world of practical chromatography, peak shapes only approach an ideal Gaussian statistical distribution. Solute band shapes are perturbed by extracolumn volumes, nonideal retention processes, and strong adsorptive interactions as they move from inlet to column to detector.

This is the fifth and final installment in a series of "LC Troubleshooting" columns about various aspects of calibration of liquid chromatography (LC) methods and problems related to calibration.

Liquid–liquid extraction (LLE), also known as solvent extraction, has long been an effective method of separating compounds having different solubilities in two immiscible liquids (1). The two liquids are typically water, perhaps with some additives, and a nonpolar organic solvent such as isooctane.

Supercritical fluid chromatography (SFC) has been practiced for approximately 50 years. Early studies used packed columns with varying degrees of success (1) and it would be fair to say that SFC did not generate much interest in the separation science community in this period.