Quantification of N-methyl morpholine N-oxide in biorefinery process solution by headspace gas chromatography


This work developed a novel method for the determination of N-methyl morpholine N-oxide (NMMO) in the solution of biorefining, such as lyocell or biomass pretreatment. Copper hydride in situ (CuH) was generated in alkaline solution from sodium borohydride and cupric ion to completely reduce NMMO to N-methyl morpholine (NMM). Finally, the generated volatile NMM was analyzed by headspace gas chromatography. The generation of in situ CuH, complete reduction of NMMO, and the gas–liquid equilibration of NMM can be synchronously completed at 80 °C in 30 min, with a cupric ion concentration of 20 μmol, sodium hydroxide (0.8 mmol), sodium borohydride (3.0 mg), and 1.0 mL 30% ammonium hydroxide in 5.0 mL aqueous solution. The lowest limit of NMMO quantification was 42 mg/L in the present method, with good precision (standard deviation = 5.62%) and accuracy (recoveries from 95.9 to 106%). The present method has high accuracy, sensitivity, and throughput. It should be a useful tool to determine the content of NMMO and allow optimize the cost efficiency.

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  1. Brooks RT, Sternglanz PD (1959) Titanometric determination of N-oxide group in pyridine-N-oxide and related compounds. Anal Chem 31(4):561–565

    CAS  Google Scholar 

  2. Gawargious YA, Ashworth MR (1971) Microdetermination of the amine oxide group in organic compounds by reduction with titanium(III). Fresenius J Anal Chem 256(2):117–119

    CAS  Google Scholar 

  3. Green JM (1996) A practical guide to analytical method validation. Anal Chem 68:305–309

    Google Scholar 

  4. Hasanzadeh E, Mirmohamadsadeghi S, Karimi K (2018) Enhancing energy production from waste textile by hydrolysis of synthetic parts. Fuel 218:41–48

    CAS  Google Scholar 

  5. He L, Chai X (2016) An efficient method for determining the α-, β-, and γ-cellulose content in fully delignified pulps by reaction-based headspace gas chromatography. J Wood Chem Technol 36(6):412–417

    CAS  Google Scholar 

  6. Hu H, Zhang Y, Zeng T, Zhou W, Chen L, Huang L, Ni Y (2018) Determination of cellulose derived 5-hydroxymethyl-2-furfural content in lignocellulosic biomass hydrolysate by headspace gas chromatography. Cellulose 25(7):3843–3851

    CAS  Google Scholar 

  7. Jeihanipour A, Aslanzadeh S, Rajendran K, Balasubramanian G, Taherzadeh MJ (2013) High-rate biogas production from waste textiles using a two-stage process. Renew Energy 52:128–135

    CAS  Google Scholar 

  8. Kabir MM, Niklasson C, Taherzadeh MJ, Horváth IS (2014) Biogas production from lignocelluloses by N-methylmorpholine-N-oxide (NMMO) pretreatment: Effects of recovery and reuse of NMMO. Biores Technol 161:446–450

    CAS  Google Scholar 

  9. Mancini G, Papirio S, Lens PN, Esposito G (2018) Increased biogas production from wheat straw by chemical pretreatments. Renew Energy 119:608–614

    CAS  Google Scholar 

  10. Metcalfe LD (1962) Potentiometric titration of long chain amine oxides using alkyl halide to remove tertiary amine interference. Anal Chem 34(13):1849–1849

    CAS  Google Scholar 

  11. Rabideau BD, Ismail AE (2015) Effect of water content in N-methylmorpholine N-oxide/cellulose solutions on thermodynamics, structure, and hydrogen bonding. J Phys Chem B 119(48):15014–15022

    CAS  PubMed  Google Scholar 

  12. Rosenau T, Potthast A, Sixta H, Kosma P (2001) The chemistry of side reactions and byproduct formation in the system NMMO/cellulose (Lyocell process). Prog Polym Sci 26(9):1763–1837

    CAS  Google Scholar 

  13. Rosenau T, Potthast A, Adorjan I, Hofinger A, Sixta H, Firgo H, Kosma P (2002) Cellulose solutions in N-methylmorpholine-N-oxide (NMMO)–degradation processes and stabilizers. Cellulose 9(3–4):283–291

    CAS  Google Scholar 

  14. Sohn OS, Fiala ES, Conaway CC, Weisburger JH (1982) Separation of morpholine and some of its metabolites by high-performance liquid chromatography. J Chromatogr A 242(2):374–380

    CAS  Google Scholar 

  15. Stockinger H, Kut OM, Heinzle E (1996) Ozonation of wastewater containing N-methyl morpholine-N-oxide. Water Res 30(8):1745–1748

    CAS  Google Scholar 

  16. Toney CJ, Friedli FE, Frank PJ (1994) Kinetics and preparation of amine oxides. J Am Oil Chem Soc 71(7):793–794

    CAS  Google Scholar 

  17. Xie W, Gong Y, Yu K (2017) Determination of total sugar content in lignocellulosic hydrolysates by using a reaction headspace gas chromatographic technique. Cellulose 24(11):4591–4597

    CAS  Google Scholar 

  18. Zhang S, Ke X, Zeng T, Ni Y, Luo X, Hu H, Chen L, Huang L (2020) Determination of N-Methyl morpholine in biomass pretreatment solutions by the ammonia-assisted headspace gas chromatography. Renewable Energy 145:2380–2386

    CAS  Google Scholar 

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The authors acknowledge the National Natural Science Foundation of China (31700507 and 21674123), National Key Research and Development Program of China (2017YFB0307900), and FAFU’s Fund for Distinguished Young Scholars (XJQ201601) for sponsoring this research.

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Correspondence to Xingye Zhang or Hui-Chao Hu.

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Zeng, T., Ke, X., Li, L. et al. Quantification of N-methyl morpholine N-oxide in biorefinery process solution by headspace gas chromatography. Cellulose (2020). https://doi.org/10.1007/s10570-020-03259-7

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  • N-methyl morpholine N-oxide
  • Cupric ion/sodium borohydride
  • Borohydride
  • N-methyl morpholine
  • Lyocell process
  • Biorefinery
  • Headspace gas chromatography