Multiplex On-Bead Isotope Dimethyl Labeling Coupled with Liquid Chromatography–High-Resolution Mass Spectrometry for Quantitative Analysis of Sulfonamides in Estuarine Ice

Abstract

A multiplex-on-bead-isotope-dimethyl-labeling method was developed for the quantitative analysis of sulfonamides (SAs) in environmental water samples by liquid chromatography-high-resolution mass spectrometry (LC-HRMS). In this method, five samples could be labeled in parallel with different isotope reagents and quantified in a single LC-HRMS analysis. Magnetic solid-phase extraction (MSPE) was employed in the sample preparation to concentrate the trace-level analytes by using lab-synthesized magnetic carbon nanospheres (MCNSs). After the analytes were captured on the MCNSs, the isotope labeling was performed directly by dispersing the MCNSs in the reaction buffer (on-bead labeling). The experimental conditions for MSPE and labeling were systematically investigated. For the tested 12 SAs, a labeling efficiency of over 99% could be achieved within 20 min. The LC-HRMS separation, including equilibration, could be achieved in 6 min. By combining MSPE (enriched 200-fold), multiplex on-bead dimethyl labeling, and LC-HRMS, all the tested SAs could be reliably quantified with limits of detection (LODs) of 0.1-5 ng/L. This method was verified using fortified pond water spiked with 12 SAs (0.01-5 μg/L), and accuracies of 81-106% were achieved with good reproducibility (RSD < 10%, n = 3), which confirmed its applicability in real-sample analysis. With this method, ice samples collected at the estuary of the Daliao River in northeast China were analyzed; nine SAs (sulfanilamide, sulfapyridine, sulfamethazine, sulfamethizole, sulfachloropyridazine, sulfamethoxypyridazine, sulfameter, sulfathiazole, and sulfisoxazole) were detected at concentrations of 0-85 ng/L, and the total concentrations were in the range of 185-402 ng/L with a median value of 274 ng/L.

Current trends in isotope‐coded derivatization liquid chromatographic‐mass spectrometric analyses with special emphasis on their biomedical application

“…This reagent can react not only with the amino group of the amino acids but also with the carboxylic group upon heating at 80°C for 0.5 h. This method was applied for the determination of amino acids in human serum. Apart from ICD reagents dedicated to biomedical applications, an innovative technique for pentaplex ICD of sulfonamides was developed by Wu et al () based on the reductive methylation of their primary amine group with 2 H 0 / 2 H 2 ‐formaldehyde and 2 H 0 / 2 H 3 ‐Na cyanoborohydride. The pentaplex ICD was performed using the following sets of reagents: CH 2 O/NaBH 3 CN, CH 2 O/NaB 2 H 3 CN, C 2 H 2 O/NaBH 3 CN, C 2 H 2 O/NaB 2 H 3 CN, and 13 C 2 H 2 O/NaB 2 H 3 CN, which produced derivatives of [M], [M + 2], [M + 4], [M + 6], and [M + 8], respectively.…”

Trends in sensitive detection and rapid removal of sulfonamides: A review

“…Based on current methodologies, sulfonamides have been detected in foods of animal origin [16] and feed [17], as well as in environmental samples [18]. Diverse complex matrices present different physicochemical properties and contain various impurities; thus, different sample preparation techniques are utilized, including magnetic solid-phase extraction (MSPE) [16,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] and SPME [37][38][39][40][41][42][43][44][45]. In some cases, the adsorbent is the key to the sample preparation technique to improve its sensitivity and reduce the time required by enhancing the enrichment efficiency.…”

“…Derived from SPE, MSPE was first proposed in 1999 [83][84][85], which has drawn considerable attention. MSPE based on a magnetic adsorbent was gradually developed for sulfonamide enrichment owing to its high efficiency for separation and pre-enrichment of target compounds from complex matrices [16,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. As shown in Figure 5, magnetic adsorbents are dispersed directly into sample solutions, which increase the contact area between adsorbents and analytes [77] and avoid the time-consuming processes of conventional SPE caused by column packing and large-volume sample loading [20,29,86].…”

Stable Isotopic Labeling and Nontarget Identification of Nanogram/Liter Amino Contaminants in Water

“…Environmental water can contain complex organic nitrogenous compounds derived from the decomposition of plants as well as from other anthropogenic discharges such as synthesized polymers, personal care products, and pharmaceuticals. − A significant portion of dissolved organic nitrogenous species (DON) is amino-containing compounds (−NH n , n = 1, 2, e.g., biogenic amines, amino acids, peptides, proteins) in source water. Several difficulties can arise from amino-containing contaminants during drinking water treatment and distribution, and the quality of drinking water can be affected. − For example, during water disinfection, amino acids, and small peptides are difficult to remove during treatment and can react with disinfectants to produce off-taste and toxic disinfection byproducts (DBPs), such as nitrosamines or halogenated nitrogenous DBPs (N-DBPs). − …”

“…Characteristic isotope patterns (e.g., 35 Cl/ 37 Cl, 79 Br/ 81 Br, 32 S/ 34 S, 14 N/ 15 N) have been used for prioritization processing of unknowns, allowing for successful identification of sulfur-containing surfactants, halogenated DBPs, and N-DBPs . For identification of unknowns in samples, special isotopes can be inherent , or introduced using isotopic labeling reagents. , The latter isotopic labeling approach is built on the previous success of using isotopic labeling techniques for proteomics and metabolomics. − However, the labeling procedures of microliters of biological samples are not suitable for trace levels of contaminants in a large volume of water.…”