Monitoring Antibiotic Residues and Corresponding Antibiotic Resistance Genes in an Agroecosystem

Table 2

Conditions for high performance liquid chromatography-tandem mass (HPLC-MS/MS) spectrometry.

Equipment	LC MS/MS (TSQ Quantum Ultra, Thermo)
LC condition	Column temp.	15°C
	Column flow rate	300 L min^−1
	Injection volume	20 L
	Mobile phase	A: 99.9% water + 0.1% formic acid
		B: 99.9% ACN + 0.1% formic acid
	Gradient	A: 96% + B: 4% (0 min)
		A: 70% + B: 30% (29 min)
		A: 96% + B: 4% (30 min)
MS condition	Ion source	ESI, positive
	Spray voltage	4500 V
	Vaporizer temp.	320°C
	Drying gas flow	10.0 L min^−1
	Drying gas and nebulizer gas	Nitrogen gas
	Sheath gas pressure	40 psig
	Aux gas pressure	20 psig