•CADs were untargeted screened based on PIS scan from artichoke.•Ten caffeoylquinic acid derivatives were detected based on PIS of m/z 191.•The potential of precursor ion scan method for semi-determination was evaluated.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.

In this work, an analytical protocol based on on-line matrix solid-phase dispersion (MSPD) ultra-fast LC–MS/MS was successfully established, for rapid determination of chloramphenicol (CAP) present in soft-shelled turtle tissues. Trace level of CAP was analysed and separated on a core-shell C18 silica column in 2 min. The performance of the on-line MSPD-LC–MS/MS method was evaluated using multi-reaction monitoring (MRM) quantification mode. The calibration curve was linear over the range of 0.01–100 ng mL−1. The mean values of relative standard deviation of intra- and inter-day ranging from 2.05% to 8.33% and from 3.05% to 10.17% were obtained, respectively. In the four fortified levels (1, 5, 7.5 and 10 ng), recoveries of CAP ranged from 92.05% to 98.07% with RSDs ⩽ 4.20%. The proposed method has been applied successfully to the analysis of CAP in soft-shelled turtle tissue sample, which demonstrates that this new instrumental coupling is ultra-fast, sensitive, reliable and environmental friendly.Highlights► On-line MSPD-HPLC–MS/MS was proposed for rapid determination of chloramphenicol. ► This protocol decreases analysis time, analytes loss and sample contamination. ► The proposed method was robust, sensitive, and efficient for trace analysis.

This study was carried out to investigate the enzymatic hydrolysis conditions on the properties of protein hydrolysate from fish muscle of the marine fish species Collichthys niveatus. About 160 fish samples were tested, and the analyzed fish species was found to be a lean fish with low fat (1.77 ± 0.01%) and high protein (16.76 ± 1.21%). Fish muscle of C. niveatus was carefully collected and hydrolyzed with four commercial enzymes: Alcalase, Neutrase, Protamex, and Flavourzyme under the conditions recommended by the manufacturers. Among the tested proteases, Neutrase catalyzed the hydrolysis process most effectively since the hydrolysate generated by Neutrase has the highest content of sweet and umami taste amino acids (SUA). The effect of hydrolysis conditions was further optimized using response surface methodology (RSM), and the optimum values for temperature, pH, and enzyme/substrate ratio (E/S ratio) were found to be 40.7 °C, 7.68, and 0.84%, respectively. Finally, the amino acid composition of the hydrolysate was analyzed by AccQ·Tag derivatization and HPLC–PDA determination. Major amino acids of the muscle of C. niveatus were threonine, glutamic acid, phenyalanine, tryptophan, and lysine, accounting for respectively 10.92%, 10.85%, 10.79%, 9.86%, and 9.76% of total amino acid content. The total content of essential amino acids was 970.7 ng·mL–1, while that of nonessential amino acids was 709.1 ng·mL–1. The results suggest that the fish muscle and its protein hydrolysate from C. niveatus provide a versatile supply of the benefits and can be incorporated as supplements in health-care foods.

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.

•A Probe-12S rDNA system was designed to distinguish ommastrephid species from others.•Species-specific systems could differentiate four common squid species in China.•This method can detect target species in single or mixed squid specimen, and can be applied to identify processed products.Squids are distributed worldwide, including many species of commercial importance, and they are often made into varieties of flavor foods. The rapid identification methods for squid species especially their processed products, however, have not been well developed. In this study, quantitative real-time PCR (qPCR) systems based on specific primers and TaqMan probes have been established for rapid and accurate identification of four common squid species (Ommastrephes bartramii, Dosidicus gigas, Illex argentinus, Todarodes pacificus) in Chinese domestic market. After analyzing mitochondrial genes reported in GenBank, the mitochondrial cytochrome b (Cytb) gene was selected for O. bartramii detection, cytochrome c oxidase subunit I (COI) gene for D. gigas and T. Pacificus detection, ATPase subunit 6 (ATPase 6) gene for I. Argentinus detection, and 12S ribosomal RNA (12S rDNA) gene for designing Ommastrephidae-specific primers and probe. As a result, all the TaqMan systems are of good performance, and efficiency of each reaction was calculated by making standard curves. This method could detect target species either in single or mixed squid specimen, and it was applied to identify 12 squid processed products successfully. Thus, it would play an important role in fulfilling labeling regulations and squid fishery control.