Functionalized monolithic columns: Recent advancements and their applications for high-efficiency separation and enrichment in food and medicine.

The chromatographic column is the core of a high-performance liquid chromatography (HPLC) system, and must have excellent separation efficiency and selectivity. Therefore, functional modification materials for monolithic columns have been rapidly developed. This study is a systematic review of the recently reported functionalized monolithic columns. In particular, the study reviews the types of functional monomers under different modification conditions, as well as the separation and detection techniques combined with chromatography, and their development prospects. In addition, the applications of functionalized monolithic columns in food analysis, biomedicine, and the analysis of active ingredient of Chinese herbal medicines in recent years are also discussed. Also reviewed are the functionalized monolithic columns for qualitative and quantitative analysis. It provided a reference for further development and application of organic polymer monolithic columns.

Graphene oxide-based a network porous poly (trially isocyanurate-co-methacrylate) monolithic column for HPLC separation of aromatic molecular and lipopeptide antibiotics.

Graphene oxide (GO) was introduced into a monolithic column and a network porous poly (GO-co-TAIC-co-MMA) monolith was prepared by redox polymerization. The internal morphology and pore size distribution of the polymer were observed by scanning electron microscopy, and the nitrogen adsorption-desorption and mercury intrusion methods. After optimization, 8 kinds of aromatic compounds were effectively separated in 5 min, and the theoretical plates number of the monolithic column exceeded 33, 070 plates m-1. Five kinds of main ingredients were separated from the traditional Chinese medicine (Schisandra) ingredients and 26 peaks were successfully separated from the fermentation broth containing natural lipopeptide antibiotics. The addition of GO material enhanced the interaction between the compound and the monolithic column, increased the binding sites, improved the uniformity of the internal pore structure of the monolithic column, and improved the separation performance of the monolith. Methodologic validation of five ingredients in Schisandra showed that the correlation coefficients of the linear regressions were in the range of 0.9987-0.9997. The intra- and inter-day values of the relative standard deviation for precision were in the range of 0.6-4.1% and 1.1-4.8%, respectively. The values of accuracy (expressed as recovery) were in the range of 97.7-103.2%, 100.5-105.0%, 98.2-101.8%, 101.3-104.1%, and 101.2-103.3% for the 5 ingredients in order. In terms of the relative standard deviation of the retention time, the reproducibility of the monolithic column M1 was <3.7%. The monolithic column based on GO has great potential in chromatographic separation.

Clinical efficacy of phentolamine in the treatment of feeding intolerance in premature infants with low birth weight.

OBJECTIVE: To discuss the clinical efficacy of phentolamine in the treatment of feeding intolerance in premature infants with low birth weight. METHODS: Seventy-one low-birth-weight infants with feeding intolerance were randomly divided into the phentolamine group and the erythromycin group (38 patients and 33 patients, respectively). The infants were given basic treatment, such as gastric lavage, temporary fasting, nutritional support and abdominal massage. The phentolamine group was intravenously pumped with phentolamine as the basis of basic treatment, while the erythromycin group was given erythromycin as the basis of basic treatment. The time for gastrointestinal symptoms to disappear, the time the basic standard was reached, the time parenteral nutrition was used, the total time enteral feeding was implemented, the length of stay, and the increase in physical indexes according to the corrected gestational age of 40 weeks of the two groups were compared. RESULTS: There was no significant difference between the phentolamine group and the erythromycin group in vomiting disappearance time or the increase in physical indicators at the corrected gestational age of 40 weeks (P>0.05), while the abdominal distension disappearance time, the time of restoration to birth weight, the time to reach the basic standard, the total time of parenteral nutrition, the total time of enteral feeding, and the length of stay in the phentolamine group were shorter than those in the erythromycin group, with significant differences (P<0.05). CONCLUSION: Phentolamine has a significant effect on alleviating symptoms and shortening the treatment time while treating feeding intolerance in premature infants with low birth weight, without adverse events, so it is worthy of clinical promotion.