DETERMINATION OF CATECHOLAMINES IN RAT BRAIN PARTS BY REVERSE‐PHASE ION‐PAIR LIQUID CHROMATOGRAPHY

TLDR

An improved reverse‑phase ion‑pair liquid chromatography method was developed for measuring catecholamines in rat brain parts. The method employs high‑efficiency microparticulate LC packings with ion‑pairing and octyl sulfate as a stationary phase modifier, reports concentrations per tissue weight and whole part, and characterizes the retention of 18 catechol derivatives. Using this approach, norepinephrine and dopamine were quantified in the hypothalamus and corpus striatum of rats, with adult hypothalamic levels of 2261 ± 274 ng/g NE and 440 ± 103 ng/g DA, striatal DA of 11,888 ± 1,840 ng/g, achieving ±5.6% precision, 60 ± 5% recovery, and linearity across 1 ng to 1 μg per sample.

Abstract

Abstract— An improved method for the measurement of catecholamines in brain parts has been developed, based on reverse‐phase ion‐pair chromatography. The new method offers the advantages of high efficiency microparticulate liquid chromatography packings and the flexibility of ion‐pair chromatography. By this approach norepinephrine and dopamine (DA) have been measured in the hypothalamus and corpus striatum of the rat brain during various stages of development (15, 21, 30 days). Data are reported on the basis of the whole part and per weight of tissue. For the adult animals, the following concentrations (ng/g wet tissue) were observed for the hypothalamus: NE = 2261 ± 274, DA = 440 ± 103, and for the corpus striatum: DA = 11,888 ± 1840. The overall precision of the method was ±5.6% relative s.d . The absolute recovery was 60 ± 5% relative s.d . and was constant over the range of 1 ng to 1 μg of dopamine or norepinephrine per tissue sample. The relative retention behavior of 18 neurologically important catechol derivatives is reported for reverse‐phase chromatography with octyl sulfate as the stationary phase modifier.