Pentobarbital quantification in the presence of phenobarbital by fluorescence polarization immunoassay

Abstract

We developed a method for measuring pentobarbital in samples that also contain phenobarbital. The phenobarbital is destroyed by adding sodium hydroxide and then heating at 95 degrees C for 60 min. Pentobarbital is not affected by this pretreatment and can then be measured with an Abbott TDx barbiturates kit. Using this method, we obtained an average analytical recovery of 98% of added pentobarbital and a correlation of y = 0.953x + 3.4 vs HPLC. The intra-assay CV was 3.7% at 25.8 mg/L; the interassay CV was 6.2% at 16.1 mg/L. Other long-acting barbiturates, e.g., hexobarbital, are also effectively destroyed by this alkali pretreatment. Other short-acting barbiturates, e.g., secobarbital, are not removed and would produce an interference.

A Direct, Competitive Enzyme-Linked Immunosorbent Assay (ELISA) as a Quantitative Technique for Small Molecules

“…This assay is particularly useful in clinical chemistry and is widely used in the diagnosis of several medical conditions including pregnancy, HIV, hyperthyroidism, and hepatitis C . However, ELISAs are useful for a variety of other applications such as detection of contaminated or genetically modified foods, , screening for drugs of abuse in body fluids or hair samples, − quantifying levels of drugs whose concentrations need to be monitored for therapeutic reasons, and screening for or quantifying environmental contaminants in soil or wastewater. − …”