tris(2-2--bipyridine)ruthenium-iii and pipecolic-acid

A new, highly sensitive chemiluminescence method for measurement of pipecolic acid in various substances such as human serum, cow's milk, beer, and apple juice has been developed. The method is based on reverse-phase ion-pair high performance liquid chromatographic separation and subsequent tris(2,2'-bipyridine)ruthenium(III) chemiluminescence detection. It was confirmed that imino acids show strong chemiluminescence upon mixing with tris(2,2'-bipyridine)ruthenium(III). A calibration graph, based on a standard pipecolic acid solution, was linear over the range 5.0x10(-9)M to 2.0x10(-5)M and the detection limit was 24fmol (signal-to-noise ratio=3). This highly sensitive and selective determination method can be applied to selected samples without purification or pre-concentration procedures. Compared to the previous HPLC methods, the proposed method is easier, more sensitive, and time-saving.

Topics: 2,2'-Dipyridyl; Animals; Beer; Beverages; Cattle; Chromatography, High Pressure Liquid; Female; Humans; Hydrogen-Ion Concentration; Luminescent Measurements; Malus; Milk; Organometallic Compounds; Pipecolic Acids; Reproducibility of Results; Ruthenium; Sensitivity and Specificity