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The conventional approach to qualitative and quantitative analyses of hemoglobin (Hb) molecules for the diagnoses of hemoglobinopathies requires a combination of tests. We used an automated HPLC (VARIANT™) system to study α-thalassemia and β-thalassemia syndromes in Thailand. The beta-thalassemia short program is applicable to the diagnosis of α-thalassemia and β-thalassemia disorders, including Hb H, EA Bart’s disease, and EF Bart’s disease, in adults, newborns, and fetuses. The system cannot quantify accurately certain Hb molecules, such as Hb H and Hb Bart’s. The alpha-thalassemia short program was therefore developed and used to quantify Hb Bart’s to detect α-thalassemia genotypes in cord blood. This automated HPLC system is an alternative approach to the diagnosis of complicated thalassemia syndromes in Thailand and Southeast Asia.

The construction and characterization of an on-line electrochemical detector especially suited for flow-rates in the order of a few microlitres per minute is described. The working electrode is tubular, of length 15 mm and I.D. 90 μm (effective volume 100 nl). It is made of a small carbon-polymer chip, giving an inexpensive, practical and disposable construction. When used with packed fused-silica liquid chromatographic columns of 0.3 mm I.D., sub-picogram detection limits are obtained. The detector is linear for amounts up to 1 ng. An exceptional feature of this detector is that it stabilizes in a few seconds after potential onset (no bseline drift). The noise level is very constant and predictable. Some examples are given of the oxidative determination of phenolic compounds and catecholamines. Coulometric efficiencies, responses versus flow-rate behaviour and peak dispersion characteristics are given.

Conventional positive fast atom bombardment (FAB) and continuous-flow FAB analysis were carried out with permethylated lacto-N-tetraose. This latter method, a new approach, has been used to analyze a mixture of permethylated oligosaccharides by liquid chromatography-mass spectrometry (LC-MS) with a packed capillary fused-silica column and the continuous-flow probe as interface. Under these conditions, we found the continuous-flow probe to be superior to the conventional probe because its low matrix level increased the signal-to-noise ratio. The analysis of the mixture of permethylated oligosaccharide alditols obtained from hen ovomucoid by LC-MS using the continuous-flow probe as interface is described.