Qing Shen

Development of an on-line matrix solid-phase dispersion/fast liquid chromatography/tandem mass spectrometry system for the rapid and simultaneous determination of 13 sulfonamides in grass carp tissues

A novel analytical protocol based on interfacing on-line matrix solid-phase dispersion (MSPD) with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for extraction and determination of 13 sulfonamide residues in grass carp tissues. The target analytes were separated on a fused-core C18-silica column with a period of 7 min and quantified by a triple-quadrupole linear ion-trap mass spectrometer in positive ion multiple-reaction monitoring (MRM) mode. The proposed method was optimized and validated according to Commission Decision 2002/657/EC. The matrix-matched calibration curves were performed at six concentration levels and good linear relationship (R²=0.993-0.998) was observed within the range of 0.1-100 ng mL⁻¹. The mean values of relative standard deviation of intra- and inter-day ranging from 1.8% to 7.8% and from 2.8% to 10.3% were obtained, respectively. Moreover, satisfied recoveries (69.0-96.3%) of all studied sulfonamides were demonstrated in different spiked levels, with RSDs ≤ 13.2%. The proposed method has been applied successfully to the analysis of sulfonamides in several grass carp samples, and the results indicated that this novel instrumental coupling was fast, sensitive, reliable and environmental friendly with good prospects.

Multi-walled carbon nanotubes as solid-phase extraction adsorbent for the ultra-fast determination of chloramphenicol in egg, honey, and milk by fused-core C18-based high-performance liquid chromatography–tandem mass spectrometry

In the present work, a high-performance liquid chromatography–tandem mass spectrometry method has been developed for the residue analysis of chloramphenicol (CAP) in several food matrices. Following the addition of D5-CAP as internal standard, egg, honey, and milk were extracted and cleaned by means of solid-phase extraction, utilizing multi-walled carbon nanotubes as sorbent. The extracts were separated on a Halo fused-core C18 column (50xa0mmu2009×u20092.1xa0mm, 2.7xa0μm) and quantified by a 4000 Q-trap mass spectrometer equipped with a TurboIonSpray™ interface using electrospray ionization and multiple-reaction monitoring mode. The method validation was performed according to the criteria of Commission Decision 2002/657/EC. The decision limit (CCα) and detection capability (CCβ) of CAP in milk were calculated for m/zxa0320.8u2009>u2009151.9. Due to the existence of slight signal suppression, quantification was performed by matrix-matched calibration curves, ranging from 0.1 to 100xa0ngxa0mL−1, with regression coefficients of 0.9993, 0.9998, and 0.9997 for egg, honey, and milk, respectively. Mean recoveries of the CAP ranged from 95.8% to 102.3%, with the corresponding intra- and inter-day variation (relative standard deviation) less than 7.13% and 8.89%, respectively. The limit of detection and limit of quantification of the method were also reported. This method successfully applied to several food matrixes (egg, honey, and milk) and can serve as a monitoring tool to avoid unacceptable levels of residues of CAP entering the food chain.

Rapid determination of caffeoylquinic acid derivatives in Cynara scolymus L. by ultra‐fast liquid chromatography/tandem mass spectrometry based on a fused core C18 column

An ultra-fast high-performance LC-ESI-MS/MS method was developed for the analysis and quantification of caffeoylquinic acid derivatives, including chlorogenic acid, 1,3-di-O-caffeoylquinic acid (cynarin) and 1,5-di-O-caffeoylquinic acid, in artichoke (Cynara scolymus L.) heads and leaves. The rapid separation (less than 4u2009 min) was achieved based on a Halo fused core C18-silica column (50u2009 mm × 2.1u2009 mm id, 2.7u2009 μm). The target compounds were detected and quantified by a triple-quadrupole mass spectrometer in multiple-reaction monitoring mode. The calibration function is linear from 0.06 to 2800u2009 ng/mL for chlorogenic acid, 0.3-3000 u2009ng/mL for cynarin and 0.24-4800u2009 ng/mL for 1,5-di-O-caffeoylquinic acid, respectively. The average recoveries ranged from 92.1 to 113.2% with RSDs ≤6.5%. Moreover, four batches of artichoke head and leaf extracts were analyzed using the established method. The results indicated that the Halo fused core column provided much faster separations and higher sample throughput without sacrificing column ruggedness and reliability, and triple-quadrupole MS provided extraordinarily lower LOQs for most of the target analytes. Comparing to conventional quantitative approaches, the established method was fast, sensitive and reliable for the determination of caffeoylquinic acid derivatives in artichoke.

Analysis of trace levels of sulfonamides in fish tissue using micro-scale pipette tip-matrix solid-phase dispersion and fast liquid chromatography tandem mass spectrometry

A micro-scale matrix solid-phase dispersion (MSPD) technique, using hydrophilic-lipophilic balance (HLB) material as sorbent and a pipette tip (PT) as the cartridge, was developed for the extraction and purification of sulfonamides in fish tissue. Eluates from PT-MSPD were analyzed using fast liquid chromatography and tandem mass spectrometry (LC-MS/MS). The method was fully validated; good linearity was obtained with correlation coefficients greater than 0.99. Precision and accuracy (RSD%) were in the range 1.4-10.3% while mean recoveries were 70.6-95.5%. With this technique, 15 aquatic samples (Collichthys niveatus) were analyzed for sulfonamides. The whole procedure took only 13min (5min for PT-MSPD and 8min for LC), materials for each sample included 5.1mL solvents (0.3mL for PT-MSPD and 4.8mL for LC), and 20mg HLB sorbent. Generally speaking, this method is indeed practical and particularly suitable for widespread drug residue analysis.

Multiwalled Carbon Nanotubes as Sorbent for Online Solid-Phase Extraction of Resveratrol in Red Wines Prior to Fused-Core C18-Based Ultrahigh-Performance Liquid Chromatography−Tandem Mass Spectrometry Quantification

An ultrafast analytical protocol based on online solid-phase extraction (SPE)/high-performance liquid chromatography-tandem mass spectrometry for the determination of resveratrol in red wines has been developed. In the present work, multiwalled carbon nanotubes (MWCNTs) were used as SPE sorbents for the analytes online extraction and cleanup. The target analytes were separated on a fused-core C18-silica column (Halo, 50 mm × 2.1 mm i.d., 2.7 μm) and quantified by triple-quadrupole linear ion trap mass spectrometry in negative ion multiple-reaction monitoring (MRM) mode. The proposed analytical procedures were carefully optimized and validated. The calibration function is linear from 0.37 to 370 ng mL(-1) and from 0.13 to 130 ng mL(-1) for trans- and cis-resveratrol, respectively. The limits of quantification (LOQs) of trans- and cis-resveratrol obtained were 0.05 and 0.06 ng mL(-1), which means that the proposed method is suitable for trace analysis of resveratrol at low-level concentration. At the three fortified levels (low, medium, and high), recoveries of resveratrol ranging from 76.9 to 108.3% were obtained. Eight red wine samples from different regions of China were analyzed. The results indicated that the present online SPE-LC-MS/MS system significantly increased sample throughput and decreased solvent consumption, exhibiting great potential to be applied for analyzing resveratrol in red wines.

Zwitterionic hydrophilic interaction solid-phase extraction and multi-dimensional mass spectrometry for shotgun lipidomic study of Hypophthalmichthys nobilis.

Zwitterionic hydrophilic interaction liquid chromatography (ZIC-HILIC) material was used as solid-phase extraction sorbent for purification of phospholipids from Hypophthalmichthys nobilis. The conditions were optimized to be pH 6, flow rate 2.0mL·min(-1), loading breakthrough volume ⩽5mL, and eluting solvent 5mL. Afterwards, the extracts were analyzed by multi-dimensional mass spectrometry (MDMS) based shotgun lipidomics; 20 species of phosphatidylcholine (PC), 22 species of phosphatidylethanoamine (PE), 15 species of phosphatidylserine (PS), and 5 species of phosphatidylinositol (PI) were identified, with content 224.1, 124.1, 27.4, and 34.7μg·g(-1), respectively. The MDMS method was validated in terms of linearity (0.9963-0.9988), LOD (3.7ng·mL(-1)), LOQ (9.8ng·mL(-1)), intra-day precision (<3.64%), inter-day precision (<5.31%), and recovery (78.8-85.6%). ZIC-HILIC and MDMS shotgun lipidomics are efficient for studying phospholipids in H. nobilis.

Precursor ion scan driven fast untargeted screening and semi-determination of caffeoylquinic acid derivatives in Cynara scolymus L.

A precursor ion scan (PIS) technique based strategy was developed for rapid screening and semi-determination of caffeoylquinic acid derivatives (CADs) in artichoke (Cynara scolymus L.) using ultra-performance liquid chromatography (UPLC) coupled with tandem mass spectrometry. 1,5-Dicaffeoylquinic acid and 5-caffeoylquinic acid were used for studying the fragmentation behaviour of two classes of CADs, setting m/z 191 as a diagnostic moiety. When it was applied to artichoke sample, ten CADs were detected and elucidated in a single PIS run. Furthermore, method validation was implemented including: specificity (no interference), linearity (≥0.9993), limit of detection (LOD<0.12 ng mL(-1)) and limit of quantification (LOQ<0.25 ng mL(-1)), precision (RSD≤3.6), recovery (91.4-95.9%) and stability (at least 12 h). This approach was proven to be a powerful, selective and sensitive tool for rapid screening and semi-determination of untargeted components in natural products.

A graphene tip coupled with liquid chromatography tandem mass spectrometry for the determination of four synthetic adulterants in slimming supplements

Slimming supplements were popularly sold online driven by the increasement of obesity and the development of social networking platform. However, events of drug abuse in slimming supplements were also frequently reported. In this study, a graphene tip solid-phase extraction (Gtip SPE) and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established for determining fenfluramine, phenolphthalein, bumetanide, and sibutramine in slimming supplements. It was validated in terms of linearity (0.9985-0.9995), LOD (1.8ngmL-1), LOQ (5.6ngmL-1), intra-day precision (<5.1%), inter-day precision (<7.3%), and recovery (82.9-95.2%). Sibutramine is the most commonly used drug, which was detected in Bihais, Galong, and Aolist, with content 12.4, 3.6, 20.3mgg-1, respectively. Phenolphthalein was also found with content lower than 5.2mgg-1. The successful application of Gtip SPE and UPLC-MS/MS method indicated its advantage in analyzing low level of contaminates resulted from violation of regulation.

PRiME pass-through purification of lignans in Silybum marianum and UPLC−MS/MS analysis

A PRiME (process, robustness, improvements, matrix effects, ease of use) pass-through cleanup procedure was developed for the extraction and purification of silychristins A and B, silybins A and B, isosilybins A and B, and silydianin in Silybum marianum. After optimizing the extracting solvent types and the sample loading volume, the crude extract was diluted to 3u202fmL with 95% acetonitrile and then loaded on the PRiME cartridge. The eluate was analyzed by ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). All the target analytes were deprotonated as [M-H]- at m/z 481 by conducting collision-induced dissociation (CID), and the major fragment ions were m/z 463 ([M-H2O-H]-), 453 ([M-CO-H]-), 355 ([M-C6H6O3-H]-), 301 ([M355-CO2-H]-), and 179 ([C10H11O3]-). Afterwards, this method was validated in terms of linearity (R2u202f>u202f0.9990), intra-day precision (1.02%-3.79%), inter-day precision (1.59%-4.87%), sensitivity (LODu202f≤u202f0.45u202fμg·kg-1 and LOQu202f≤u202f1.50u202fμg·kg-1), and recovery (76.9-103.4%, RSDu202f<u202f8.90%). Finally, the proposed protocol was successfully applied to eight batches of S. marianum samples. The total content of the seven active compounds varied amongst the batches from different places of origin.

Rapid evaporative ionization mass spectrometry based lipidomics tracking of grass carp (Ctenopharyngodon idellus) during in vitro multiple-stage digestion

A rapid evaporative ionization mass spectrometry (REIMS) method was developed for lipidomics tracking of Ctenopharyngodon idellus during in vitro multiple-stage digestion. The REIMS conditions were optimized such that the temperature of the heating probe was 500 °C, sample amount was 30 mg, and the flow rate of auxiliary solvent was 100 μL min-1. The results showed that the phospholipids were detected with variety and quantity in the crude and multiple-stage digested samples. The enzymatic effect on the phospholipids is varied depending on the phospholipid classes, and the hydrolysis rate of phospholipids increased as the degree of unsaturation of the acyl chain increased. The principal component analysis (PCA) indicated that the ions at m/ z 809.61, 811.63, and 857.52 were the most noticeable species digested during the process. This method exhibited great potential in fast lipidomics profiling for inspecting the characteristics of nutritional lipid absorption digestion in human gastrointestin.