Cephalosporins: Unique Effects of DLC Columns
It is well known that antibiotics play a crucial role in treating infectious diseases in humans. Among them, cephalosporins, a series of semi-synthetic antibiotics, are widely used in clinical practice due to their broad spectrum of activity, strong antibacterial effects, and fewer adverse reactions.
As shown in the figure, cephalosporin drugs are a class of compounds containing carboxylate groups. Due to the presence of these electron-rich carboxyl groups, traditional stainless steel columns in chromatographic analysis can cause specific adsorption to the metal surface of the column, leading to low sensitivity and poor recovery rates in chromatography. Welch's Diamond-Like Carbon Columns can effectively resolve this issue.
Using the determination of cefuroxime sodium content as an example, we will share relevant insights with you!
Case Study
Columns:
- Ultisil® XB-C8 (4.6×250mm, 5μm, conventional stainless steel column)
- Ultisil® DLC XB-C8 (4.6×250mm, 5μm, diamond-coated column)
Mobile Phase: Acetate buffer/acetonitrile = 85/15
Detection Wavelength: 273nm
Column Temperature: 30°C
Flow Rate: 1.0mL/min
Injection Volume: 20μL
Preparation of Mobile Phase:
- Acetate Buffer: Dissolve 0.68g of anhydrous sodium acetate and 5.8g of glacial acetic acid in water, dilute to 1000mL, mix well, adjust the pH to 3.40 with glacial acetic acid, filter, and ultrasonicate for use.
- Mobile Phase: Acetate buffer/acetonitrile = 85/15, mixed using dual pumps.
Preparation of Sample Solution:
- Sample Solution: Dissolve 10mg of cefuroxime sodium sample in a 100mL volumetric flask with water, dilute to the mark, and mix well.
Comparative Results:
Figure 2. Chromatograms of Cefuroxime Sodium Content Determination using Two Types of Column Tubes
Conclusion:
As shown in Figure 2, the chromatographic column with a Diamond-Like Carbon (DLC) tube achieved higher column efficiency (an increase of approximately 8.4% in the number of theoretical plates of the main peak) and a greater peak area (an increase of approximately 6.9% in peak area) compared to the stainless steel column when detecting cefuroxime sodium content.
It is evident that utilizing Diamond-Like Carbon (DLC) columns can effectively reduce the adsorption of metal-sensitive compounds (e.g., samples containing carboxylate groups), resulting in improved chromatographic performance. In studies such as drug metabolism, where high-sensitivity analysis is crucial, this coating technology provides us with a new direction to effectively address such issues.
Product Information
The chromatographic columns with diamond-like carbon (DLC) coating offer numerous advantages in the analysis of metal-sensitive compounds. Welch Materials continues to steadily expand this series of chromatographic columns (highlighted in blue is the newly launched product today).
Welch Diamond-Like Carbon (DLC) Series Chromatographic Columns
Frequently Asked Questions
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What are Diamond-Like Carbon (DLC) coated chromatographic columns?
The columns utilize high-performance surface-coated diamond-like carbon (DLC) film technology, aimed at providing excellent peak shapes and sensitivity for a variety of compounds.
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Are DLC chromatographic columns just coated tubes?
No, the coating includes not only the tube but also the sieve plate.
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What types of samples are DLC columns commonly used for analysis?
- Biological Samples: Such as proteins, peptides, monoclonal antibodies, oligonucleotides, etc.
- Metal-Sensitive Small Molecule Samples: Phosphorylated and carboxylated analytes.
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What are the advantages of DLC columns?
- Inertness of the column reduces specific adsorption.
- Improvement in peak shape enhances separation efficiency.
- Flatter baselines and higher sensitivity.
- Significant reduction in sample residue, decreasing column activation and passivation time, thereby enhancing experimental efficiency.
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Are DLC columns compatible with all HPLC systems?
Yes, DLC-coated chromatographic columns are compatible with all HPLC systems.