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Published on: May 7, 2018
Determination of Residual Dimethyl Sulfate in Cephalosporin Using HS-SPME/GC-MS
1University of Shanghai for Science and Technology, School of Environment and Architecture, Jungong Road NO 516, Yangpu District, Shanghai 200093, China.
Abstract:
Dimethyl sulfate (DMS) is widely used in manufacturing process but because of its genotoxicity nature, it should be monitored at trace levels (1 μg/mL). It is complicated and difficult to quantify DMS in cephalosporin with traditional method. Herein, a method for quantifying residual DMS in cephalosporin was developed, without complex sample preprocessing, no need for a large amount of solvent, employing headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Compared with polydimethylsiloxane (PDMS)/divinylbenzene and polyacrylate fibers, PDMS was more suitable for absorbing DMS. The research showed that the PDMS fiber should be changed after 50 adsorption-desorption cycles. Linear regression analysis of the calibration curve demonstrated a robust linear relationship, with R2 of 0.999, across a concentration range of 0.25 to 4.0 μg/mL. The method underwent rigorous validation for specificity, linearity, precision and accuracy. This method was proven effective in measuring DMS in complex matrices. The limits of detection and quantification for this method is 0.05 and 0.25 μg/mL, respectively, which has room for improvement.
Insights
A new method effectively quantifies genotoxic dimethyl sulfate (DMS) in cephalosporin. This technique uses headspace SPME and GC-MS, simplifying analysis and enabling trace-level monitoring.
Area of Science:
- Analytical Chemistry
- Environmental Science
Background:
- Dimethyl sulfate (DMS) is a genotoxic industrial chemical requiring trace-level monitoring.
- Quantifying DMS in complex matrices like cephalosporin is challenging with traditional methods.
Purpose of the Study:
- To develop a simplified, sensitive method for quantifying residual DMS in cephalosporin.
- To validate the method's performance for complex sample analysis.
Main Methods:
- Headspace solid-phase microextraction (SPME) using a polydimethylsiloxane (PDMS) fiber.
- Gas chromatography-mass spectrometry (GC-MS) for sensitive detection and quantification.
- Optimization of SPME fiber usage (50 adsorption-desorption cycles).
Main Results:
- Achieved a robust linear relationship (R2 = 0.999) for DMS quantification from 0.25 to 4.0 μg/mL.
- Established method limits of detection (0.05 μg/mL) and quantification (0.25 μg/mL).
- Demonstrated method's effectiveness in complex cephalosporin matrices with rigorous validation.
Conclusions:
- The developed headspace SPME-GC-MS method offers a simplified, solvent-reduced approach for DMS analysis in cephalosporin.
- The method provides sensitive and accurate quantification of trace DMS levels, crucial for safety monitoring.
