GC-MS Identification Characteristics of Butyl Acrylate and Methyl Methacrylate?

Chemical Process

April 10, 2025

BUTYL ACRYLATE AND METHYL METHACRYLATE GC-MS IDENTIFICATION CHARACTERISTICS

In the chemical industry, n-butyl acrylate (Butyl Acrylate) and methyl methacrylate (Methyl Methacrylate, referred to as MMA) are two important organic compounds, widely used in plastics, coatings, adhesives and other industries. Due to the differences in chemical structure between the two, it is of great significance to identify and distinguish them by gas chromatography-mass spectrometry (GC-MS). In this paper, the analysis principle of the GC-MS, the characteristics of both chromatography and mass spectrometry are analyzed in detail.

1. GC-MS Technology Introduction

Gas chromatography-mass spectrometry (GC-MS) is a commonly used separation and detection technology, which can provide both physical properties (such as retention time) and chemical structure information (such as mass spectrum fragments) of compounds. The GC part is mainly used for the separation of samples, and the MS part is used for the detection and analysis of the molecular composition of compounds. Through GC-MS, the target compounds in complex mixtures can be analyzed qualitatively and quantitatively quickly and accurately.

In this issue, we will use GC-MS techniques to identify n-butyl acrylate and methyl methacrylate. Although the two are similar in chemical structure, there are significant differences, which provides a basis for GC-MS analysis.

2. of Butyl Acrylate and Methyl Methacrylate by GC

chemical structure difference The chemical formula of n-butyl acrylate is C≡H₂ O₂, and the structural formula is CH₂ = CH-CO-O-C. The chemical formula of methyl methacrylate is C≡H≡O₂, and the structural formula is CH = C(CH)-CO-O-CH. The difference between the two is mainly reflected in the side chain part: the side chain of n-butyl acrylate is n-butyl (-C? H), while the side chain of methyl methacrylate is methyl (-CH?).
gas chromatographic retention time Due to the difference in polarity and molecular weight, the retention time on the gas chromatography column will also be different. n-Butyl acrylate has a larger molecular weight, longer side chain, and higher polarity, so the retention time on the GC column is usually longer than that of methyl methacrylate. By choosing appropriate chromatographic conditions (such as column temperature program), the two can be distinguished significantly.
Factors affecting GC retention time

Column type: non-polar column (such as OV-1) and medium polar column (such as DB-17) can be used to separate the two compounds, but according to the sample polarity to choose the appropriate stationary phase.
Column temperature program: Usually use temperature program to ensure that the sample is completely separated.
Nitrogen flow rate and carrier gas purity: Proper carrier gas conditions help improve separation efficiency.

3. of n-Butyl Acrylate and Methyl Methacrylate by MS

of Molecular Ion Peak (Molecular Ion Peak) In mass spectrometry, the molecular ion peaks of the two have obvious differences:

Butyl acrylate molecular weight is 120g/mol, molecular ion peak is [M]-= 120;
to be 106g/mol, and the molecular ion peak was [M]-> = 106.
The two can be directly distinguished by the mass number of the molecular ion peak.

typical fragment ion

n-butyl acrylate The mass spectral fragments of n-butyl acrylate are mainly derived from the cleavage of the side chain butyl and the cleavage of the carbonyl region. Typical fragments include:
- Butyl cleavage produces Cover Hover (molecular weight 57);
- Alkylation fracture produced by C (molecular weight 79);
- Hydroxyl cleavage yields C≡H≡C (molecular weight 110).
Methyl methacrylate The mass spectral fragmentation of methyl methacrylate is mainly derived from the cleavage of the methacrylic acid moiety and the cleavage of the methoxy moiety. Typical fragments include:
- Methyl cleavage produced Cover Hbenzo (molecular weight 43);
- Alkylation fragmentation produced by C≡H, (molecular weight 68);
- Methoxy cleavage produces Cover HB (molecular weight 86).

of Fragment Analysis in

By analyzing the typical fragments of both, their chemical structures can be further confirmed. For example, fragments of n-butyl acrylate will reflect the characteristics of n-butyl (e. g. C? H?), while fragments of methyl methacrylate will reflect the characteristics of the methacrylic part (e. g. C? H?).

4. GC-MS identification in the note

Sample Preparation

Ensure sample purity and avoid impurity interference.
If the sample is a mixture, it needs to be separated and purified.

chromatographic condition optimization

According to the sample polarity and molecular weight to select the appropriate column and stationary phase.
Optimize the column temperature program to ensure that the target compound is completely separated.

Mass spectrometry parameter setting

Select the appropriate ionization mode (such as EI mode) to obtain a clear mass spectrum.
Adjust the ion source temperature and voltage to ensure sufficient sensitivity.

Data Parsing

Comprehensive analysis of retention time, molecular ion peaks and fragment ions, to avoid a single basis for a part of the conclusion.
Compare standard spectra (such as the NIST database) to improve accuracy.

5. summary

Butyl acrylate and methyl methacrylate have significant identification characteristics in GC-MS analysis. The two can be accurately distinguished by the retention time of the gas chromatography and the fragmentation characteristics of the mass spectrum. In practical applications, combined with optimized chromatographic and mass spectrometry conditions, reliable results can be obtained. GC-MS technology not only enables the rapid identification of these two compounds, but also provides a powerful tool for quality control and production monitoring in the chemical industry.

I hope this article can provide you with valuable information. If you have more questions about GC-MS technology or the analysis of related compounds, please leave a message to discuss!