Head-to-Head Comparison of High-Performance Liquid Chromatography versus Nuclear Magnetic Resonance for the Quantitative Analysis of Carbohydrates in Yiqi Fumai Lyophilized Injection

Abstract

Carbohydrate analysis can be used as a standard analysis for quality control of industries of plants, foods and pharmaceuticals. Quantitative 1H NMR spectroscopy (qNMR) is an excellent alternative to chromatography-based mixture analysis. However, the application of qNMR in sugar analysis has rarely been reported. In this study, the performance of qNMR in sugar analysis was investigated and compared with the results from HPLC analysis. A head-to-head comparison of qNMR (internal and external standard methods) versus HPLC (PMP pre-column derivatization HPLC, HPLC-RID and HPLC-ELSD) based on quantitative analysis of four carbohydrates (fructose, glucose, sucrose and maltose) in Yiqi Fumai lyophilized injection (YQFM) is presented. Both assays showed similar performance characteristics, including linearity range, accuracy, precision and recovery, and analysis times of less than 30 min/sample. After methodological validation, both qNMR and HPLC have good accuracy, precision and stability. Indeed, the qNMR method is simple, sensitive and rapid in quantifying the four sugars. By analysis of variance (ANOVA) for sugar content with HPLC and qNMR methods, we demonstrated that the two analytical methods had no significant difference and could be used interchangeably for the quantitative analysis of carbohydrates.

Analysis of the Effects of Surfactants on Extracellular Polymeric Substances

“…Palomares [31] found that surfactants interact with the cell membrane barrier of Gram-negative bacteria, such as Enterobacter cloacae, during Gram-negative stress cultures, resulting in increased cell damage and leakage. SDS breaks the non-covalent bonds inside and outside the protein molecule, i.e., reduces the disulfide bonds within the molecule, and binds to the protein causing it to unfold, thus disrupting the [32] secondary and tertiary structure of the protein molecule, changing the original spatial conformation and denaturing the protein [33]. When the SDS breaks the non-covalent bonds inside and outside the protein molecule, i.e., reduces the disulfide bonds within the molecule, and binds to the protein causing it to unfold, thus disrupting the [32] secondary and tertiary structure of the protein molecule, changing the original spatial conformation and denaturing the protein [33].…”

“…SDS breaks the non-covalent bonds inside and outside the protein molecule, i.e., reduces the disulfide bonds within the molecule, and binds to the protein causing it to unfold, thus disrupting the [32] secondary and tertiary structure of the protein molecule, changing the original spatial conformation and denaturing the protein [33]. When the SDS breaks the non-covalent bonds inside and outside the protein molecule, i.e., reduces the disulfide bonds within the molecule, and binds to the protein causing it to unfold, thus disrupting the [32] secondary and tertiary structure of the protein molecule, changing the original spatial conformation and denaturing the protein [33]. When the concentration of SDS is higher than 1 × 103 mg/L, it causes severe damage to the cell barrier and prevents growth.…”