Simultaneous determination of residual tetracyclines in foods by high-performance liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry

Monitoring the degradation of tetracycline by ozone in aqueous medium via atmospheric pressure ionization mass spectrometry

“…The choice of APCI rather than ESI source is because typical APCI conditions can prevent an interface obstruction usually caused by the required use of oxalic acid (a nonvolatile compound) in the LC mobile phase [33]. Recent reports have shown that other advanced oxidative processes (AOP), such as UV and TiO 2 /UV, also promote the degradation of tetracycline in aqueous solution but lead to a different set of products [34 -37].…”

Liquid chromatography – tandem mass spectrometry method for the determination of ten tetracycline residues in muscle samples

“…To minimise these undesirable effects, acidic mobile phases are generally used. Towards this, formic, citric, phosphoric, and acetic acids are used (3,8,24). Triethylamine is a very common additive used to block silanols groups in reversed-phase chromatography when separating basic analytes (21).…”

“…Triethylamine is a very common additive used to block silanols groups in reversed-phase chromatography when separating basic analytes (21). Oxalic acid in a mobile phase shows a significant efficiency in softening the effect of residual silanols on the stationary phase and good TCs separation without tailing (6,16,24,30). However, it should be taken into account that mobile phases containing non-volatile compounds used in LC -MS or LC -MS/MS may cause clogging at the interface and a build-up of deposits in the ion source (26,27).…”

“…For effective extraction of TCs from tissues with high extraction efficiency, buffers within the range of 4.0 -5.0 pH values are recommended (20). In most studies, extraction with a mild acidic solvent containing EDTA (0.1 M EDTA -McIlvaine buffer, pH 4.0), citric acid, and oxalic acid has been described to overcome these undesirable properties with acceptable extraction efficiencies (7,15,24,27,28,30). Cooper et al found the citrate buffer (pH 5.0) with ethyl acetate to be the most effective in TCs isolation (13).…”

“…Fluorescence detection was also reported by several authors (17,18,22,28). The sensitivity and selectivity of these methods might be improved when coupled with mass spectrometry detection (3,4,8,24,25). Using a mass spectrometer for antibacterial compound detection offers many advantages, such as independence from a chromophor and fluorophor, the possibility of structural information, lower detection limits, and easier separation of co-eluting peaks (26).…”