Liquid chromatography-electrospray ionization-mass spectrometric quantitation of juvenile hormone III in whole body extracts of the Formosan subterranean termite.
Juvenile hormone (JH) III is responsible for control of a variety of insect physiological and developmental states, including caste differentiation of the Formosan subterranean termite (Coptotermes formosanus Shiraki). We report here a simplified, efficient sample preparation and an optimized LC-ESI-MS method for quantifying JH III in whole body extracts. Sample preparation comprises hexane extraction (from termite whole bodies) and C18 cartridge purification. Previous LC-ESI-MS protocols exhibited the following two problems: (1) ion fragmentation differed when comparing spectra from insect samples and authentic JH III and (2) a JH III monitoring ion was not resolved from other unknown compounds in whole body samples from termites. To overcome these problems, we used a pentafluorophenyl LC column and water/acetonitrile containing ammonium acetate as solvent. In a mass chromatogram (m/z 235) of termite samples, a peak was detected at the retention time of authentic JH III, and MS(2) of this peak confirmed that the ion is a fragment of JH III, [M-CH(3)OH+H](+), being the base peak in both termites and authentic JH III samples. The protocol enables quantification of JH III in a single termite with signal/noise >10:1 and the limit of quantification is 21pg.
Miyazaki
Masao
M
Department of Biological Sciences, Louisiana State University and A&M College, Baton Rouge, LA 70803, USA.
Mao
Lixin
L
Henderson
Gregg
G
Laine
Roger A
RA
D000085:Acetates / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D005464:Fluorobenzenes / Q000737:chemistry; D007301:Insect Hormones / Q000032:analysis*; D020049:Isoptera / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry; D012680:Sensitivity and Specificity; D012717:Sesquiterpenes / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D005466:Fluorocarbons
D000085:Acetates; D000097:Acetonitriles; D005464:Fluorobenzenes; D007301:Insect Hormones; D010636:Phenols; D012717:Sesquiterpenes; C085539:2,3,4,5,6-pentafluorophenol; D005466:Fluorocarbons; C036585:juvenile hormone III; C018824:ammonium acetate; C032159:acetonitrile