Characterization of natural rubber concerning its components and molecular weight in Taraxacum kok‐saghyz Rodin using pyrolysis gas chromatography‐mass spectrometry

Abstract

Taraxacum kok‐saghyz Rodin (TKS) has abundant natural rubber in its root and the molecular weight of its natural rubber is higher than that in Hevea brasiliensis. Thus, TKS is an excellent alternative for the commercial production of natural rubber. The content and molecular weight of natural rubber are two qualitative indicators. Efficient determination for both indicators is still a challenge. In this study, we developed a method to simultaneously determine the content and molecular weight of natural rubber in TKS with pyrolysis－gas chromatography‐mass spectrometry. The content of natural rubber was quantified by internal standard method. We optimized the pyrolysis temperature and chromatographic method during content determination. The limits of detection and quantification were 0.47 and 1.56 μg, respectively. In addition, the arachidonic acid methyl ester, an unsaturated fatty acid proposed from the α‐end group of natural rubber, was quantified to obtain the number of natural rubber polymers. Based on the content and the polymer number, we also quantified the molecular weight of natural rubber. Thus, the content and molecular weight of natural rubber were simultaneously determined in TKS. Our study provides a new perspective for the high throughput analysis of natural rubber.

Rapid Determination of Taraxacum kok-saghyz Rubber Content Using a Pyrolyzer Hyphenated with a Miniaturized Mass Spectrometer

“…Table 1 compares representative methods for detecting NR. Traditional methods for assessing NR content, such as the differential weight method based on solvent extraction [12][13][14], nuclear magnetic resonance (NMR) spectroscopy [15], infrared (IR) spectroscopy [16], near-infrared (NIR) spectroscopy [17], and pyrolysis gas chromatography-mass spectrometry (PY-GC-MS) [18], are time-consuming, inaccurate, costly, and environmentally unfriendly. These drawbacks have rendered them inadequate for meeting the evolving needs of modern TKS development of NR-related industrial.…”

“…Analytical pyrolysis is a technique involving the rapid heating of a sample in a wellcontrolled environment, thus inducing the swift breakdown of the sample into volatile, small molecular fragments. In the field of rubber engineering, the application of analytical pyrolysis involves the comprehensive and systematic analysis of polymer materials through the combination of pre-treatment extraction methods and modern analytical techniques, such as gas chromatography and/or mass spectrometry (PY-GC/MS) [18,19]. Portable mass spectrometers with small sizes and easily selectable quadrupoles are increasingly employed for on-site rapid analysis, establishing them as one of the most competitive in-field sampling techniques.…”

“…Researchers have explored the pyrolysis products and mechanisms of NR, demonstrating the reliability of analytical pyrolysis for the structural analysis and determination of rubber [28]. Utilizing PY-GC/MS, Takeno et al [18,29] conducted the first quantitative study of rubber in plant leaves, determining the content of polyisoprene and polybutadiene and correlating the release of isoprene and limonene to their molecular weights. In previous research, our team applied PY-GC-MS to quantify NR in TKS, establishing a stable and environmentally friendly method based on the linear relationship between the peak area of the main pyrolysis product, limonene, and the injected rubber standard quantity [30].…”

Rapid Determination of Taraxacum kok-saghyz Rubber Content by Pyrolyzer Hyphenated with a Miniaturized Mass Spectrometer

“…Analytical pyrolysis is a technique involving the rapid heating of a sample in a well-controlled environment, inducing the swift breakdown of the sample into volatile small molecular fragments. In the field of rubber engineering, the application of analytical pyrolysis involves the comprehensive and systematic analysis of polymer materials through the combination of pre-treatment extraction methods and modern analytical techniques such as gas chromatography and/or mass spectrometry (PY-GC/MS) [19,20]. Portable mass spectrometers with small sizes and easily selectable quadrupoles are increasingly employed for on-site rapid analysis, establishing themselves as one of the most competitive in-field sampling techniques.…”