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LAAN-A-LM-E131
Application Liquid Chromatograph Mass Spectrometry
News
Multi-Residue Veterinary Drug Analysis of >200
Compounds using MRM Spectrum Mode by LC-MS/MS
No. C161
Veterinary drugs are used for therapeutic, Table 2 MS/MS Acquisition Parameters
metaphylactic, prophylactic and growth promotion Mass spectrometry
purposes. To provide an assurance that food from Mass spectrometer Shimadzu LCMS-8060
animals is safe with regards to residues of veterinary Pause time/dwell time 1 msec/3 msec
medicines, regulatory authorities have established
Polarity switching time Pos/neg switching time set to 5 msec
Maximum Residue Limits (MRL's) for certain drugs in Scope 218 drugs in positive ion mode
target tissues and animal species. Some
(including internal standards)
pharmacologically active compounds identified by 11 drugs in negative ion mode
regulatory authorities have been prohibited and their Structure Analytics (in house
hazardousness at all levels are being considered (EU development tool)
regulation EC 37/2010; Commission Decision Source temperatures 350 °C; 300 °C; 150 °C
2003/181/EC; 21CFR Part 556 Tolerances for Residues (interface; heat block; DL)
of New Animal Drugs in Food). In this article, we Gas flows 3 L/min; 10 L/min; 10 L/min
describe how a triple quadrupole mass spectrometer, (nebulising; heating; drying)
which is both highly sensitive and selective,
contributes to reducing false positive and false Advantages of MRM Spectrum Mode
negative reporting when using a measurement mode The measurement method can be easily set using the
called MRM Spectrum mode. MRM Spectrum mode MRM optimization tool and measurement window
acquires a high number of fragment ion transitions for (MRM Synchronization) settings of LabSolutions LCMS.
each target compound and generates fragmentation The method achieves high data densities and a high
spectra that can be used in routine library searching data sampling rate across each elution peak. This
and compound verification using reference library approach generates a consistent loop time and
match scores.
sampling rate producing reliable quantitation and
1
2
2
David Baker * , Laetitia Fages * , Eric Capodanno * , Neil Loftus * 1 peak integration. It also provides great operator-
1
* : Shimadzu, Manchester, UK friendliness in routine simultaneous analysis of
2
* : Phytocontrol, Nimes, France veterinary drugs by enhancing flexibility in qualifier
and quantifier ion selection. The number of fragment
Samples and Analysis Conditions ion transitions generated from a single precursor ion is
limited only by the chemical structure of the veterinary
Samples of beef, egg, honey, milk and salmon were drug.
extracted and spiked with veterinary drugs in the
calibration range of 0.001 to 0.1 mg/kg. Repeatability
was assessed at low and high concentrations. Samples Results
were measured using Shimadzu's Nexera X2 UHPLC MRM Spectrum mode was used to acquire a high
and LCMS-8060 triple quadrupole mass spectrometer number of fragment ion transitions for each veterinary
(Table 1 and 2). Over 200 veterinary drugs were drug target. For chlortetracycline, 11 precursor-
targeted and over 2,000 MRM transitions in both ESI +/- fragment ion transitions were acquired using
were monitored during a gradient elution time of optimized collision energies (Fig. 1). Acquiring a high
12 minutes. number of fragment ion transitions enables generation
of fragmentation spectra which can be used in library
Table 1 UHPLC Conditions
searching and compound verification for each
Liquid chromatography veterinary drug. (Chlortetratcycline is a tetracycline
UHPLC Nexera LC system class of antimicrobials. According to the Sixth ESVAC
Analytical column Restek Biphenyl (100 × 2.1, 2.7 μm) report published in 2016, of the overall sales of
antimicrobials in the 29 EU countries in 2014, the
Column temperature 40 °C
largest amount, expressed as a proportion of mg/PCU,
Flow rate 0.4 mL/minute
was accounted for by tetracyclines (33.4 %). This is
Solvent A 0.1 % formic acid 0.5 mM ammonium formate
solution followed by penicillins (25.5 %) and sulfonamides
Solvent B 0.1 % formic acid in methanol (11.0 %). Chlortetracycline was selected as a
Binary Gradient Time (mins) %B Time (mins) %B representative target).
0.00 2 14.60 2
12.50 100 17.50 Stop
14.50 100
