Recent Advances in Catecholamines Analytical Detection Methods and Their Pretreatment Technologies.

Catecholamines (CAs), including adrenaline, noradrenaline, and dopamine, are neurotransmitters and hormones that play a critical role in regulating the cardiovascular system, metabolism, and stress response in the human body. As promising methods for real-time monitoring of catecholamine neurotransmitters, LC-MS detectors have gained widespread acceptance and shown significant progress over the past few years. Other detection methods such as fluorescence detection, colorimetric assays, surface-enhanced Raman spectroscopy, and surface plasmon resonance spectroscopy have also been developed to varying degrees. In addition, efficient pretreatment technology for CAs is flourishing due to the increasing development of many highly selective and recoverable materials. There are a few articles that provide an overview of electrochemical detection and efficient enrichment, but a comprehensive summary focusing on analytical detection technology is lacking. Thus, this review provides a comprehensive summary of recent analytical detection technology research on CAs published between 2017 and 2022. The advantages and limitations of relevant methods including efficient pretreatment technologies for biological matrices and analytical methods used in combination with pretreatment technology have been discussed. Overall, this review article provides a better understanding of the importance of accurate CAs measurement and offers perspectives on the development of novel methods for disease diagnosis and research in this field.

Calcium peroxide pre-treatment improved the anaerobic digestion of primary sludge and its co-digestion with waste activated sludge.

Primary sludge (PS) and Waste activated sludge (WAS) as two main sludge streams in wastewater treatment plants are commonly anaerobically co-digested, which though may be differently affected by pretreatment. Previous work has found that calcium peroxide (CaO2) pretreatment effectively enhanced anaerobic digestion of WAS. However, the feasibilities of this strategy on PS anaerobic digestion and co-digestion of WAS and PS are still unclear. Herein, this work provided new insights into these systems. Biomethane potential test demonstrated that CaO2 pretreatment at 0.02-0.26 g/g-volatile suspended solids (VSS) promoted anaerobic digestion of PS. Then the feasibility of CaO2 pretreatment for improving anaerobic co-digestion of PS and WAS mixture was confirmed, with the highest improvement in methane production, VSS destruction and sludge reduction being approximately 37.4%, 38.9% and 19.9%, achieved at 0.14 g/g-VSS of CaO2. Process modelling analysis revealed that CaO2 pretreatment increased both degradable faction and actually degraded fraction in sludge mixture. The changes of sludge characteristics via pretreatment and key enzyme activity in sludge anaerobic co-digestion system demonstrated that increased CaO2 concentration resulted in increased soluble organics release from sludge mixture in the pretreatment stage and inhibited activity of coenzyme F420 responsible for methanogenesis. Further mechanism investigation disclosed that OH-, O2- and OH were main contribution factors, and the order of their contributions were OH- >O2- >OH. This work laid the theoretical foundation and provided guidance for the practical application of CaO2 pre-treatment technology.

Applications of capillary electrophoresis in the fields of environmental, pharmaceutical, clinical, and food analysis (2019-2021).

So far, the potential of capillary electrophoresis in the application fields has been increasingly excavated due to the advantages of simple operation, short analysis time, high-resolution, less sample consumption, and low cost. This review examines the implementations and advancements of capillary electrophoresis in different application fields (environmental, pharmaceutical, clinical, and food analysis) covering the literature from 2019 to 2021. In addition, ultrasmall sample injection volume (nanoliter range) and short optical path lead to relatively low concentration sensitivity of the most frequently used ultraviolet-absorption spectrophotometric detection, so the pretreatment technology being developed has been gradually utilized to overcome this problem. Despite the review being focused on the development of capillary electrophoresis in the fields of environmental, pharmaceutical, clinical, and food analysis, the new sample pretreatment techniques of microextraction and enrichment fit excellently to capillary electrophoresis in recent three years are also described briefly.

Weak-base pretreatment to increase biomethane production from wheat straw.

Weak-base pretreatment of wheat straw was investigated for its ability to improve biomethane production. Anaerobic digestion (AD) was performed on wheat straw pretreated with 3%, 5%, or 7% Na2CO3 as a weak base. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) spectra demonstrated disruption of lignocellulosic structures by pretreatment. In the 5% Na2CO3 treatment group, cellulose and hemicellulose were retained effectively, with efficient removal of lignin. The removal rates of cellulose, hemicellulose, and lignin were 27.9%, 20.4%, and 31.0%, respectively, after 5% Na2CO3 pretreatment. The methane content (53.3-77.3%) was improved in the 5% Na2CO3 treatment group, with maximum methane production (307.9 L/kg VS) that was 41.6% higher than that of the untreated sample. Cellulose and hemicelluloses were degraded 59.3% and 56.3% after AD. It took 20 days to reach 80% of the maximum cumulative methane production for the 5% Na2CO3 pretreatment group, which was 4 days faster than the untreated group. These results indicate that 5% Na2CO3 pretreatment improve the lignocellulose structure of wheat straw, allowing better biodegradability of wheat straw in AD for increased biogas production, enhanced methane content, and decreased digestion time.

Preparation of high-quality concentrated fragrance flaxseed oil by steam explosion pretreatment technology.

In this study, flaxseed was pretreated by steam explosion technology and subsequently pressed to prepare flaxseed oil. GC, UPLC, HPLC, and GC-MS techniques were used to analyze the quality characteristics of the prepared flaxseed oil. These included the food safety risk indices, micronutrient components, and oxidative stability. The effects of different steam explosion pressures on the quality characteristics and relative volatile components of flaxseed oil were also investigated. The results revealed that steam explosion pretreatment technology could significantly increase the oil yield, improve micronutrient content, and strengthen the oxidation stability of the product. Moreover, the food safety risk indices (e.g., benzopyrene) were controlled within a reasonable range, while the fatty acid content remained almost unchanged. Notably, the relative pyrazine content in the total volatile components of flaxseed oil was 68.25% when the steam explosion pressure reached 1.2 MPa. This was considered as the main factor that contributed to the unique concentrated fragrance of the produced flaxseed oil. To prove the superiority of the steam explosion pretreatment, we compared this technique with traditional high-temperature roasting and popular microwave pretreatment techniques. The results revealed that flaxseed oil prepared by steam explosion pretreatment displayed the best quality characteristics and most concentrated fragrance. Thus, steam explosion technology shows great potential for application to produce high-quality concentrated fragrance flaxseed oil. This study provides significant reference and guidance for the preparation process of flaxseed oil.

Fabricating and Characterizing the Microfluidic Solid Phase Extraction Module Coupling with Integrated ESI Emitters.

Microfluidic chips coupling with mass spectrometry (MS) will be of great significance to the development of relevant instruments involving chemical and bio-chemical analysis, drug detection, food and environmental applications and so on. In our previous works, we proposed two types of microfluidic electrospray ionization (ESI) chip coupling with MS: the two-phase flow focusing (FF) ESI microfluidic chip and the corner-integrated ESI emitter, respectively. However the pretreatment module integrated with these ESI emitters is still a challenging problem. In this paper, we concentrated on integrating the solid phase micro-extraction (SPME) module with our previous proposed on-chip ESI emitters; the fabrication processes of such SPME module are fully compatible with our previous proposed ESI emitters based on the multi-layer soft lithography. We optimized the structure of the integrated chip and characterized its performance using standard samples. Furthermore, we verified its abilities of salt removal, extraction of multiple analytes and separation through on-chip elution using mimic biological urine spiked with different drugs. The results indicated that our proposed integrated module with ESI emitters is practical and effective for real biological sample pretreatment and MS detection.

[Research progress of pretreatment technology for mycotoxin detection in Chinese materia medica and complex matrices].

In the processes of planting, harvest, transport and storage, improper treatment of Chinese materia medica (CMM) and foodstuffs and agricultural products will result in fungal growth and mycotoxins contamination, which will not only directly affect the quality, safety and efficacy of these complex matrices, but also seriously threaten the consumers' health and lives. Therefore, the establishment of high-throughout analytical methods with high sensitivity for the determination of mycotoxins in CMM and foodstuffs and agricultural products at trace levels will provide reliable references for reducing the risk of mycotoxin exposure in humans. Due to the matrix complexity of CMM and foodstuffs and agricultural products, highly-effective pretreatment technologies are necessary for the establishment of such analytical techniques. In this review, the current extraction and purification methods commonly used for the detection of mycotoxins were summarized, the importance of pretreatment techniques for the precise quantification of mycotoxins in complex matrices such as Chinese herbal medicines was highlighted, as well as the development tendency about the pretreatment techniques for mycotoxins in complex matrices in the future was proposed.

Research progress of pretreatment technology for mycotoxin detection in Chinese materia medica and complex matrices / 中国中药杂志

In the processes of planting, harvest, transport and storage, improper treatment of Chinese materia medica (CMM) and foodstuffs and agricultural products will result in fungal growth and mycotoxins contamination, which will not only directly affect the quality, safety and efficacy of these complex matrices, but also seriously threaten the consumers' health and lives. Therefore, the establishment of high-throughout analytical methods with high sensitivity for the determination of mycotoxins in CMM and foodstuffs and agricultural products at trace levels will provide reliable references for reducing the risk of mycotoxin exposure in humans. Due to the matrix complexity of CMM and foodstuffs and agricultural products, highly-effective pretreatment technologies are necessary for the establishment of such analytical techniques. In this review, the current extraction and purification methods commonly used for the detection of mycotoxins were summarized, the importance of pretreatment techniques for the precise quantification of mycotoxins in complex matrices such as Chinese herbal medicines was highlighted, as well as the development tendency about the pretreatment techniques for mycotoxins in complex matrices in the future was proposed.