A rapid and sensitive quantitation of Amitraz in plasma by gas chromatography with nitrogen-phosphorus detection and its application for pharmacokinetics.
We report a simple, sensitive, and rapid quantitation of Amitraz in plasma after Extrelut-3 column extraction by gas chromatography with nitrogen-phosphorus detection (GC-NPD). The plasma sample was diluted four-fold with borate buffer (0.01M, pH 11), put into an Extrelut-3 column, left for 15 min, and then eluted with 15 mL of n-hexane. The n-hexane eluate was evaporated under nitrogen gas flow at room temperature. The residue was reconstituted with 0.1 mL of acetone containing nitrazepam as an internal standard. A 2-microL aliquot was injected into a wide-bore capillary column GC-NPD. The detection limit was 0.5 ng/mL and linearity was obtained in the range of 1-200 ng/mL. Amitraz in the buffer at pH 11 remained stable in a freezer for one week at -20 degrees C. The GC-NPD method was found useful in studying the pharmacokinetics of a single dose intravenous administration of Amitraz to a dog.
Ameno
K
K
Department of Forensic Medicine, Kagawa Medical School, Japan.
Fuke
C
C
Ameno
S
S
Kiriu
T
T
Shinohara
T
T
Ijiri
I
I
D000818:Animals; D002021:Buffers; D002849:Chromatography, Gas / Q000379:methods; D004285:Dogs; D006863:Hydrogen-Ion Concentration; D007275:Injections, Intravenous; D007306:Insecticides / Q000097:blood* / Q000493:pharmacokinetics; D009584:Nitrogen / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D015203:Reproducibility of Results; D014052:Toluidines / Q000097:blood* / Q000493:pharmacokinetics
D002021:Buffers; D007306:Insecticides; D014052:Toluidines; D010758:Phosphorus; C014983:amitraz; D009584:Nitrogen