一般社団法人
日本質量分析学会

第3回材料分析部会講演会

第3回講演会「質量分析による高分子キャラクタリゼーションの最前線」

日程：

２０２０／２／１７（月）　１４：００～（受付は１３：３０～）
１４：００～１５：００：見学会　　１５：００～１７：００：講演会

場所：

産業技術総合研究所　つくばセンター　第５事業所２号館６階第４会議室
〒305-8565　茨城県つくば市東1-1-1　つくば中央5-2
https://www.aist.go.jp/aist_j/guidemap/tsukuba/center/tsukuba_map_c.html
※ 第5事業所受付（5-2）までお越しください。

参加費：

無料

プログラム（講演は英語で行います）：

14:00～15:00

産業技術総合研究所　機能化学研究部門　概要紹介、見学会

15:00～15:05

開会の辞

15:05～16:05

講演１ ”Mass Spectrometry of Digital Polymers”
Dr. Laurence Charles (Professor Aix Marseille University, CNRS, Institute for Radical Chemistry, France)

16:05～16:55

講演２ “A triadic approach to polymer mass spectrometry”
Thierry N.J. Fouquet（産総研　機能化学研究部門）

16:55～17:00

閉会の辞

定員：

40名程度

申し込み締め切り：

2月10日（月）

参加申し込み方法：

以下の内容をご記載のうえ、下記問い合わせ先までメールにてご連絡ください。
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申込み、問い合わせ先：

佐藤貴弥（日本電子）
E-mail: material15_at_mssj.jp（_at_を@に変更してください）

Abstract（講演１）

Information-containing polymers are a new class of synthetic macromolecules prepared by multi-step approaches in order to ensure precise control over their co-monomeric sequence and their chain length monodispersity. In such sequence-defined synthetic polymers, co-monomers can be used as letters of an alphabet (for example, the 0- and 1-bits of the ASCII code) to write molecular messages. As long as the building units are of different mass, tandem mass spectrometry (MS/MS) is a very efficient method to sequence these macromolecules and hence read messages encoded in their backbone. However, in order to achieve the full sequence coverage requested for reliable decoding of these molecular messages, the structure of these polymers has to be optimized to control their dissociation. This approach has been successfully implemented to develop various series of digital polymers dedicated to different applications. Sequence-controlled oligo(urethane)s are designed for anti-counterfeiting technologies. They exhibit extremely simple MS/MS pattern due to a single dissociation reaction occurring per repeating units: as a result, messages encoded in these species can be deciphered by measuring peak-to-peak distance corresponding to the mass of one or the other co-monomer. Due to their robust structure and their low toxicity level, these species can be used as molecular labels in different materials as well as in biological applications. Secured communications were demonstrated with poly(alkoxyamine phosphodiester)s (PAPs) that include a decrypting key based on slight variation of fragment collision cross section: accordingly, encoded messages could only be read by coupling MS/MS to ion mobility spectrometry. Since molecular encoding offers an unrivaled storage density, sequence-defined polymers can also be conceived for massive information storage. This was shown with byte-truncated poly(phosphodiester)s that can be produced as long chains using automated phosphoramidite chemistry and readily sequenced using a two-stage activation approach.

Abstract（講演２）

The molecular and structural analysis of natural and synthetic polymers is crucial for the development of new high-performance materials with fine-tuned properties. Mass spectrometry (MS) has proven very powerful to provide numerous features such as the molecular weight distribution, the nature of repeating units and chain ends, the deformulation of blends, or the architecture of macromolecules among others. Since industrial materials or natural products are invariably complex with formulations of additives and homo- or copolymers, dispersity of chain lengths and structures or limited solubility, a basic mass analysis by electrospray (ESI) or matrix-assisted laser desorption ionization (MALDI) low-resolution MS is not sufficient to get the full picture.
The Polymer Chemistry Group of the Research Institute for Sustainable Chemistry (ISC, AIST) has developed with academic and corporate collaborators a strong expertise in a multi-step characterization of natural and synthetic polymeric materials. Size exclusion chromatography, thermal desorption and pyrolysis, or on-plate hydrolytic partial degradation successfully fractionate disperse samples or release short oligomers from poorly soluble samples. Using ESI, MALDI, direct analysis in real time (DART) or a variation of SALDI to mass-analyze intact chains or release specific fragments from the prepared samples, a high-resolution mass analysis (e.g. multiturn time-of-flight mass spectrometer) provides unambiguous molecular or chemical fingerprints. The nature of the repeating units and the end-groups, and the content in co-monomers can be evaluated thanks to accurate mass measurements readily correlated to elemental compositions. On the other hand, low-resolution tandem or multistage mass analysis (MS/MS or MSⁿ, e.g. ion trap) can reveal microstructural details such as the position of a specific moiety along an oligomeric chain thanks to the sequential selection / activation / dissociation of ions and the understanding of their fragmentation pathways. Finally, congested single or summed mass spectra recorded from the first two steps with numerous homo- or copolymeric distributions, different charge states or intense background signal can be processed, visualized and interpreted using a dynamic graphical method developed in-house based on the Kendrick masses to extract the tiniest piece of information.
The combination of a dedicated sample preparation prior to a robust mass analysis followed by a clever data processing forms an almighty triad allowing us to record and explore signals from samples out of reach of a simple mass analysis.