Simultaneous Analysis of Multiple Classes of Antibiotics by Ion Trap LC/MS/MS for Assessing Surface Water and Groundwater Contamination

Abstract

Solid-phase extraction (SPE) and liquid chromatography in combination with ion trap mass spectrometry (LC/MS/MS) conditions were optimized for the simultaneous analysis of 13 antibiotics belonging to multiple classes and caffeine in 3 different water matrixes. The single-cartridge extraction step was developed using a reversed-phase cartridge, resulting in recoveries for the 14 compounds ranging from 71 to 119% with relative standard deviations of 16% or lower. The analytes were separated in one chromatographic run, and the SPE-LC/MS/MS detection limits ranged from 0.03 to 0.19 microg/L. The SPE procedure was validated in groundwater, surface water, and wastewater. The analysis of samples from each of the three water matrixes revealed clindamycin (1.1 microg/L) in surface water and multiple antibiotics in wastewater (0.10-1.3 microg/L). The use of identification points to unambiguously assign the identity of antibiotics in various water matrixes was applied to an ion trap data-dependent scanning method, which simultaneously collects full scan and full scan MS/MS data for the unequivocal identification of target analytes.

Determination of penicillin G and its degradation products in a penicillin production wastewater treatment plant and the receiving river

“…To make sure that no overlapping peaks from other components in water samples exist, the confirmation ratio of the peak areas of molecular ion and two fragment ions has been evaluated for each analyte in standards and in all water samples including each wastewater compartment and river water samples, and the variability of the ratio between water samples and standards was all within 15% as shown in Table S2 (Supporting Information). It has been reported that LOQ for PEN G was 15-20 ng/L using LC-ESI/tandem MS (Hirsch et al, 1999;Sacher et al, 2001), while in this study the instrumental LOQ for PEN G fortified in ultrapure water was estimated to be 0.93 mg/L as shown in Table 2, based on the concentration corresponding to the signal at the y-intercept plus 10 times its standard deviation (Batt and Aga, 2005;Lindberg et al, 2005). The LOQs for all the analytes in river water were also determined in the same way by fortifying all the analytes in blank river water from R1.…”

“…Abuse of antibiotics and the existence of residual antibiotics in the environment have been linked with the formation of antibiotic resistance (Boxall et al, 2003;Silver and Bostian, 1993). The occurrences of several kinds of antibiotics like macrolides and sulfonamides have been reported in many environmental samples such as municipal wastewater (McArdell et al, 2003), surface water, groundwater (Batt and Aga, 2005), sludge and sediments (Lindberg et al, 2005). Penicillin G (PEN G) (pK a ¼ 2.75) was the first antibiotic found by humans and applied for human bacterial disease (Clarke et al, 1949), as it could bind to penicillin-binding proteins (PBPs) of bacteria which are involved in cell wall synthesis and thus inhibit bacterial cell wall synthesis (Hou and Poole, 1971).…”

Time-Resolved Fluoroimmunoassay as an Advantageous Approach for Highly Efficient Determination of Sulfonamides in Environmental Waters

“…It was observed that for all three SAs both S max and IC 50 remained constant in the pH range of 6.0-9.0, except that the IC 50 of SMZ increased sharply with an increase of pH from 8.0 to 9.0. The constant S max of SMZ at pH 8.0-9.0 suggested no conformational change of the SMZ Mab (42); thus, the increased IC 50 was attributed to the transformation to the anionic form of SMZ (pK a2 ) 7.49 (13)) that reduced its affinity to Mab. As the pK a2 value was 5.60 for SMX and 6.50 for SDZ, these two SAs were present mainly as the anionic form at pH 6.0-9.0 and thus had constant affinity to Mab's.…”

An overview of analytical methodologies for the determination of antibiotics in environmental waters

“…It is due to the following elution step when impurities can be eluted together with desirable analytes. The elution of cartridges is usually done by organic solvents such as MeOH (in majority of studies), acidified MeOH [4,19] or acetonitrile (ACN) [44][45][46]. The elution of cationexchange cartridges is done by the mixture of MeOH and ammonia according to the specific sorbent and guidelines from manufacturer.…”