No abstract

Based on the regulations of the Ministry of Health and Welfare (MOHW) of Taiwan in 2017, an analysis of 373 pesticides in food was conducted using the MOHW official method. The analyses involved the use of either liquid chromatography mass spectrometry (LC-MS) with electrospray ionization (ESI) or gas chromatography mass spectrometry (GC-MS) with electron ionization (EI). In this study, the applicability of detecting pesticides using atmospheric pressure chemical ionization (APCI) was investigated and evaluated. The pesticides were separated using an aqueous solution of ammonium formate with methanol as the mobile phase, and ionization efficiency was compared between APCI, ESI, and EI coupled with triple quadrupole mass spectrometer using multiple reaction monitoring (MRM) acquisition. Among the 196 pesticides that were originally analyzed by ESI, 164 could be successfully detected by APCI with 6 showing a higher sensitivity when APCI was used. Among the 177 pesticides that were analyzed by EI, 43 could be successfully detected by APCI. The results also showed that APCI gave superior ionization efficiency for pesticides containing triazine, imidazole, triazole, and pyrazole groups.

Highly polar pesticides (HPP) are a group of pesticides that are characterize as low Log Kow. Many high-throughput multi-residue analysis methods based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous determination of such polar pesticides have been proposed. In this article, we summarize the various sample preparation methods including quick polar pesticides (QuPPe), dispersive solid phase extraction (dSPE), solid phase extraction (SPE) and QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe), especially for QuPPe, which are mainly used for the determination of HPP in foods. In addition, we summarize LC-based separation methodologies that are currently used for the analysis of HPP in foods, including reversed-phase chromatography (RPC), hydrophilic interaction liquid chromatography (HILIC), ion chromatography (IC) and mixed-mode chromatography (MMC). Finally, the current mass spectrometry-based methodologies for the analysis of HPP are summarized with a specific focus on MS configurations and acquisition modes.

Fountain pen ink contains dyes, pigments, or nanoparticles as colorants; water and ethylene glycol or an organic solvent as the vehicle. The dyes in fountain pen ink are usually negatively charged acid dyes. In this study, various types of black fountain pen ink (5 dye‐based and 5 nanoparticle‐based) were investigated by ultraviolet–visible (UV–Vis) absorption spectroscopy, Ion Pair High Performance Liquid Chromatography Diode‐Array Detector (IP‐HPLC‐DAD), Matrix Assisted Laser Desorption/Ionization Time‐of‐Flight Mass Spectrometry (MALDI‐TOF‐MS), and Liquid Chromatography Quadrupole Time‐of‐Flight Mass Spectrometry (LC‐Q/TOF‐MS) analysis. UV–Vis spectroscopy of fountain pen ink samples showed different profiles despite their similar color. MALDI‐TOF‐MS analyses successfully differentiated 10 of the inks. Nanoparticle‐based ink, which is usually darker than dye‐based ink, showed the same UV absorption at 240 nm. The use of LC‐Q/TOF‐MS, however, allowed the 5 dye‐based fountain pen ink samples to be differentiated from one another. On the basis of the combined results of all analytical methods mentioned above, the discriminating power values were 0.71–1.00. Among them, MALDI‐TOF‐MS could successfully distinguish fountain pen ink samples with similar black colors and provide an easy analytical approach for the differentiation and identification of various types of fountain pens.

Microplastics (MPs) (microscopic plastic particles) are defined as plastic fragments in the range of 1 to 5 mm. They are invisible and usually too small to be seen by humans but pollution by MPs has become an issue due to the rising use of plastic products. Pollution of microscopic plastics has gained international attention in recent years and has become an important issue in the field of environmental protection, food safety, and human health. Numerous studies have reported that MPs have the potential for causing detrimental effects in various species. The focus of this mini review was on LC-MS-based metabolomics research into this issue by targeted and untargeted approaches. We also summarized biomarkers for assessing toxicity in land and aquatic species that are induced by MPs with different sizes and shapes, type of monomer, and the dose. Based on previous research results, MPs have the potential for affecting energy metabolism and the immune system, chronic inflammation, and neurotransmitter disorders in a wide variety of species. These biomarkers discovered by metabolomics are consistent with other methods, showing the reliability of LC-MS-based metabolomics. Further research is highly anticipated to explore other toxicity effects that are induced by MPs.