Screening for β2-agonists in Meat Products

Adulterated fodder fed to meat animals is one way contaminants enter the food chain and impact the consumer. One family of adulterants, the β₂-agonists, are common pharmaceuticals that as a side effect lead to enhanced growth in livestock when delivered in high dosages, leading some manufacturers of animal feed and farmers to include them as illegal fodder additives in Europe and China. However, meat products contaminated with β₂-agonists may produce intoxication in the consumer, rendering efficient detection of contamination imperative for food safety.

In order to enhance sensitivity and mass accuracy when compared with previous detection methods, Guo et al. developed an ultra high performance liquid chromatography Q-Orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) protocol for the simultaneous detection and quantitation of 12 β₂-agonists in the muscle tissue of food animals (pork, beef, mutton, and chicken):¹

β₂-agonists Evaluted

salbutamol	cimaterol	bromchlorbuterol	ractompamine
isoxsuprine	mapenterol	terbutaline	cimbuterol
clenbuterol	brombuterol	mabuterol	clorprenaline

 

To do this, the team harnessed an Accela LC pump and autosampler coupled with a Q-Exactive platform equipped with a HESI-II ion source (both Thermo Scientific). For instrument control and data processing, the team used XCalibur 2.1 and Q Exactive 2.1 software (both Thermo Scientific). Using these tools, the team performed simultaneous qualitative and quantitative analysis in full MS/data-dependent MS² mode, noting that this combination is ideal for efficient screening and has been proven effective for applications like doping control and the detection of pesticide residues.

In almost all cases, the method described here effectively analyzed a greater number of analytes when compared to other methods and produced superior limits of detection (LODs) when compared with the results of previous studies.¹

β₂-agonist LODs and Linear Ranges

method	LOD	linear range
CE (5 analytes)	0.10 µg/mL	0.20–100 µg/mL
CE (4 analytes)	22.45 ng/mL	0.069–2.77 µg/mL
LC-MS (7 analytes)	0.05 µg/kg	n/a
LC-MS (16 analytes)	0.06 µg/kg	0.1–10 µg/kg
LC-MS (3 analytes)	0.12 µg/kg	0.5–20 ug/kg
HRMS (12 analytes)	0.0033 µg/kg (viz. 0.0165 ng/mL)	0.01–50 ug/kg (viz. 0.025–125 ng/mL)

Guo et al. applied their method to 400 batches of meat collected by the Food and Drug Administration of Shandong Province, China. For identification, they relied on three criteria: retention time, exact mass, and MS2 fragmentation; for quantitation, they used the peak areas of the precursor ions from the extracted ion chromatograms. Of the samples, only 4.25% tested positive for β₂-agonists, including salbutamol, clenbuterol, ractopamine and clorprenaline. Several of these contaminants presented at ultra-trace levels, highlighting the importance of enhanced sensitivity for reliable detection. For this reason, the UHPLC-Q-Orbitrap HRMS method presented here for simultaneous screening, identification, and quantification has been adopted for routine screening of β₂-agonists in meat products.

Reference

1 Guo C. et al. (2015) ‘Ultra-trace analysis of 12 ˇ2-agonists in pork, beef, mutton and chicken by ultrahigh-performance liquid-chromatography–quadrupole-orbitrap tandem mass spectrometry.’ Journal of Pharmaceutical and Biomedical Analysis, 107: 526–534.