No-discharge atmospheric pressure chemical ionization: evaluation and application to the analysis of animal drug residues in complex matrices.
Alternative ionization methods are increasingly being utilized to increase the versatility and selectivity of liquid chromatography/mass spectrometry (LC/MS). One such technique is the practice of using commercially available atmospheric pressure chemical ionization (APCI) sources with the corona discharge turned off, a process termed no-discharge APCI (ND-APCI). The relative LC/MS responses for several different classes of veterinary drugs were obtained by using ND-APCI, electrospray ionization (ESI), and APCI. While the ND-APCI-MS and -MSn spectra for these compounds were comparable with ESI, ND-APCI provided advantages in sensitivity and selectivity for some compounds. Drugs that were charged in solution as cations or sodium adducts responded particularly well with this technique. Instrumental parameters such as temperatures, gas and liquid flow rates, and source design were investigated to determine their effect on the process of ND-APCI. This paper explores advantages of using ND-APCI for the determination and confirmation of drug residues that might be found in food matrices, including malachite green residues in fish tissue and avermectin residues in milk.
U.S. Food and Drug Administration, Animal Drugs Research Center, Denver Federal Center, Denver, CO 80225, USA. Sherri.turnipseed@fda.hhs.gov
Sherri B
SB
Turnipseed
Wendy C
WC
Andersen
Christine M
CM
Karbiwnyk
José E
JE
Roybal
Keith E
KE
Miller
D000818:Animals; D000981:Antiprotozoal Agents / Q000032:analysis; D001274:Atmospheric Pressure; D002417:Cattle; D004396:Coloring Agents; D004350:Drug Residues / Q000032:analysis*; D005399:Fishes; D005504:Food Analysis; D007202:Indicators and Reagents; D007559:Ivermectin / Q000031:analogs & derivatives / Q000032:analysis; D008460:Meat / Q000032:analysis; D008892:Milk / Q000737:chemistry; D012015:Reference Standards; D012394:Rosaniline Dyes / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization; D019155:Veterinary Drugs / Q000032:analysis*
D000981:Antiprotozoal Agents; D004396:Coloring Agents; D007202:Indicators and Reagents; D012394:Rosaniline Dyes; D019155:Veterinary Drugs; C005095:malachite green; D007559:Ivermectin; C019264:avermectin