Development of a high performance liquid chromatography/mass spectroscopy method for the determination of strychnine concentrations in insects used to assess potential risks to insectivores.
A high performance liquid chromatography/mass spectrometry (HPLC/MS) method was developed in support of a study to assess potential tertiary risks posed to insectivores by strychnine baited pocket gophers (Thomomys sp.). Necropholous insects are primary consumers of pocket gopher carcasses. A field study was conducted to collect insects from strychnine-baited and control pocket gopher carcasses. The majority of the insects collected were from the orders Diptera (flies, assayed separately as adults and larvae), Coleoptera (beetles), and Hymenoptera (ants and wasps, assayed separately). Samples (0.5 g) were extracted in acetic acid (2%) and analyzed with the mass spectrometer configured for tandem mass spectrometry. For most of the samples the strychnine concentrations were less than the method limit of detection. However, strychnine concentrations as high as 0.338, 0.341, 0.698, and 0.034 microg/g were detected in ants, fly adults, fly larvae, and beetles, respectively. This information collected with the HPLC/MS method is critical for assessing potential non-target hazards for insectivores.
Stahl
Randal S
RS
US Department of Agriculture, APHIS/WS, National Wildlife Research Center, 4101 LaPorte Avenue, Fort Collins, CO 80521, USA. randal.s.stahl@aphis.usda.gov
Arjo
Wendy M
WM
Wagner
Kim K
KK
Furcolow
Carol
C
Nolte
Dale L
DL
Johnston
John J
JJ
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004175:Diptera; D020387:Food Chain; D013058:Mass Spectrometry / Q000379:methods*; D018570:Risk Assessment; D013331:Strychnine / Q000032:analysis*
D013331:Strychnine