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Quantitative Raman spectroscopy in turbid matter: reflection or transmission mode?

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Abstract

Raman intensities from reflection (X R ) and transmission (X T ) setups are compared by calculations based on random walk and analytical approaches with respect to sample thickness, absorption, and scattering. Experiments incorporating strongly scattering organic polymer layers and powder tablets of pharmaceutical ingredients validate the theoretical findings. For nonabsorbing layers, the Raman reflection and transmission intensities rise steadily with the layer thickness, starting for very thin layers with the ratio X T /X R  = 1 and approaching for thick layers, a lower limit of X T /X R  = 0.5. This result is completely different from the primary irradiation where the ratio of transmittance/reflectance decays hyperbolically with the layer thickness to zero. In absorbing materials, X R saturates at levels that depend strongly on the absorption and scattering coefficients. X T passes through a maximum and decreases then exponentially with increasing layer thickness to zero. From the calculated radial intensity spreads, it follows that quantitative transmission Raman spectroscopy requires diameters of the detected sample areas be about six times larger than the sample thickness. In stratified systems, Raman transmission allows deep probing even of small quantities in buried layers. In double layers, the information is independent from the side of the measurements. In triple layers simulating coated tablets, the information of X T originates mainly from the center of the bulk material whereas X R highlights the irradiated boundary region. However, if the stratified sample is measured in a Raman reflection setup in front of a white diffusely reflecting surface, it is possible to monitor the whole depth of a multiple scattering sample with equal statistical weight. This may be a favorable approach for inline Raman spectroscopy in process analytical technology.

Raman spectroscopy in turbid matter

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References

  1. Salzer R, Siesler HW (eds) (2009) Infrared and Raman spectroscopic imaging, 1st edn. Wiley, Weinheim

    Google Scholar 

  2. Buckley K, Matousek P (2011) Recent advances in the application of transmission Raman spectroscopy to pharmaceutical analysis. J Pharm Biomed Anal 55:645–652. doi:10.1016/j.jpba.2010.10.029

    Article  CAS  Google Scholar 

  3. Wikström H, Lewis IR, Taylor LS (2005) Comparison of sampling techniques for in-line monitoring using Raman spectroscopy. Appl Spectrosc 59(7):934–941

    Article  Google Scholar 

  4. Kalantri PP, Somani RR, Makhija DT (2010) Raman spectroscopy: a potential technique in analysis of pharmaceuticals. Der Chemica Sinica 1:1–12

    CAS  Google Scholar 

  5. Johansson J, Sparen A, Svensson O, Folestad S, Claybourn M (2007) Quantitative transmission Raman spectroscopy of pharmaceutical tablets and capsules. Appl Spectrosc 61:1211–1218. doi:10.1366/000370207782597085

    Article  CAS  Google Scholar 

  6. Sparén A, Johansson J, Svensson O, Folestad S, Clayborn M (2009) Transmission Raman spectroscopy for quantitative analysis of pharmaceutical solids. Am Pharmaceut Rev 62–71

  7. Gao X, Jehng J-M, Wachs IE (2002) In situ UV–vis–NIR diffuse reflectance and Raman spectroscopic studies of propane oxidation over ZrO2-supported vanadium oxide catalysts. J Catal 209(1):43–50. doi:10.1006/jcat.2002.3635

    Article  CAS  Google Scholar 

  8. Eliasson C, Matousek P (2007) Noninvasive authentication of pharmaceutical products through packaging using spatially offset Raman spectroscopy. Anal Chem 79(4):1696–1701. doi:10.1021/ac062223z

    Article  CAS  Google Scholar 

  9. Stone N, Baker R, Prieto CH, Matousek P (2008) Novel Raman signal recovery from deeply buried tissue components. In: Mahadevan-Jansen A, Petrich W, Alfano RR, Katz A (eds) Biomedical optical spectroscopy. Proceedings of SPIE. SPIE-OSA, p 68530N. doi:10.1117/12.786442

  10. Srinivasan S, Schulmerich M, Cole JH, Dooley KA, Kreider JM, Pogue BW, Morris MD, Goldstein SA (2008) Image-guided Raman spectroscopic recovery of canine cortical bone contrast in situ. Opt Express 16(16):12190–12200

    Article  CAS  Google Scholar 

  11. Matousek P (2006) Inverse spatially offset Raman spectroscopy for deep noninvasive probing of turbid media. Appl Spectrosc 60(11):1341–1347

    Article  CAS  Google Scholar 

  12. Eliasson C, Macleod NA, Jayes LC, Clarke FC, Hammond SV, Smith MR, Matousek P (2008) Non-invasive quantitative assessment of the content of pharmaceutical capsules using transmission Raman spectroscopy. J Pharm Biomed Anal 47:221–229. doi:10.1016/j.jpba.2008.01.013

    Article  CAS  Google Scholar 

  13. Hargreaves MD, MacLeod NA, Smith MR, Andrews D, Hammond SV, Matousek P (2011) Characterization of transmission Raman spectroscopy for rapid quantitative analysis of intact multi-component pharmaceutical capsules. J Pharm Biomed Anal 54:463–468. doi:10.1016/j.jpba.2010.09.015

    Article  CAS  Google Scholar 

  14. Nah S, Kim D, Chung H, Han S-H, Yoon M-Y (2007) A new quantitative Raman measurement scheme using Teflon as a novel intensity correction standard as well as the sample container. J Raman Spectros 38(5):475–482. doi:10.1002/jrs.1667

    Article  CAS  Google Scholar 

  15. Oelkrug D, Brun M, Rebner K, Boldrini B, Kessler RW (2012) Penetration of light into multiple scattering media; model calculations and reflectance experiments. Part I: the axial transfer. Appl Spectrosc 66(8):934–943. doi:10.1366/11-06518

    Article  CAS  Google Scholar 

  16. Matousek P, Clark IP, Draper ERC, Morris MD, Goodship AE, Everall N, Towrie M, Finney WF, Parker AW (2005) Subsurface probing in diffusely scattering media using spatially offset Raman spectroscopy. Appl Spectrosc 59(4):393–400

    Article  CAS  Google Scholar 

  17. Oelkrug D, Brun M, Hubner P, Egelhaaf H-J (1996) Optical parameters of turbid materials and tissues as determined by laterally resolved reflectance measurements. Proc SPIE 2925:106–115. doi:10.1117/12.260831

    Article  CAS  Google Scholar 

  18. Schrader B, Bergmann G (1967) Die Intensität des Ramanspektrums polykristalliner Substanzen. Fresenius J Anal Chem 225(2):230–247. doi:10.1007/bf00983673

    Article  CAS  Google Scholar 

  19. Matousek P, Parker AW (2006) Bulk Raman analysis of pharmaceutical tablets. Appl Spectrosc 60(12):1353–1357. doi:10.1366/000370206779321463

    Article  CAS  Google Scholar 

  20. Everall N, Matousek P, MacLeod N, Ronayne KL, Clark IP (2010) Temporal and spatial resolution in transmission Raman spectroscopy. Appl Spectrosc 64:52–60. doi:10.1366/000370210790571963

    Article  CAS  Google Scholar 

  21. Everall N, Priestnall I, Dallin P, Andrews J, Lewis I, Davis K, Owen H, George MW (2010) Measurement of spatial resolution and sensitivity in transmission and backscattering Raman spectroscopy of opaque samples: impact on pharmaceutical quality control and Raman tomography. Appl Spectrosc 64:476–484. doi:10.1366/000370210791211646

    Article  CAS  Google Scholar 

  22. Matousek P (2007) Raman signal enhancement in deep spectroscopy of turbid media. Appl Spectrosc 61(8):845–854

    Article  CAS  Google Scholar 

  23. Oelkrug D (1994) Fluorescence spectroscopy in turbid media and tissues. In: Lakowicz JR (ed) Topics in fluorescence spectroscopy, vol 4. Plenum Press, New York, pp 223–253. doi:10.1007/0-306-47060-8_8

    Chapter  Google Scholar 

  24. Allen E (1964) Fluorescent white dyes: calculation of fluorescence from reflectivity values. J Opt Soc Am 54(4):506–514

    Article  Google Scholar 

  25. Oelkrug D, Kortüm G (1968) Zur Berechnung der Lumineszenzreabsorption bei pulverförmigen Substanzen. Zeitschrift für Physikalische Chemie NF 58:181–188. doi:10.1524/zpch.1968.58.1_4.181; see also Kortüm G (1969) Reflectance Spectroscopy, Springer, Berlin

  26. Fukshansky L, Kazarinova N (1980) Extension of the Kubelka–Munk theory of light propagation in intensely scattering materials to fluorescent media. J Opt Soc Am 70(9):1101–1111

    Article  CAS  Google Scholar 

  27. Gade R, Kaden U (1990) True luminescence spectra and luminescence quantum yields of molecules adsorbed on light-scattering media. Part 1.—theory. J Chem Soc Chem, Faraday Trans 86(22):3707–3712

    Article  CAS  Google Scholar 

  28. Oelkrug D, Brun M, Mammel U (1994) Spatial fluorescence profiles in multiple light scattering systems. J Lumin 60–61:422–425. doi:10.1016/0022-2313(94)90181-3

    Article  Google Scholar 

  29. Kubelka P (1948) New contributions to the optics of intensely light-scattering materials. Part I. J Opt Soc Am 38(5):448–448

    Article  CAS  Google Scholar 

  30. Oelkrug D, Brun M, Hubner P, Rebner K, Boldrini B, Kessler RW (2012) Penetration of light into multiple scattering media: model calculations and reflectance experiments. Part II: the radial transfer. Appl Spectrosc 66(8):934–943

    Google Scholar 

  31. Koenig JL, Boerio FJ (1969) Raman scattering and band assignments in polytetrafluoroethylene. J Chem Phys 50(7):2823–2829

    Article  CAS  Google Scholar 

  32. Peacock CJ, Hendra PJ, Willis HA, Cudby MEA (1970) Raman spectrum and vibrational assignment for poly(tetrafluoroethylene). J Chem Soc Inorg Phys Theor 2943–2947

  33. Rabolt JF, Fanconi B (1978) Raman scattering from finite polytetrafluoroethylene chains and a highly oriented TFE-HFP copolymer monofilament. Macromolecules 11(4):740–745. doi:10.1021/ma60064a025

    Article  CAS  Google Scholar 

  34. Legeay G, Coudreuse A, Legeais J-M, Werner L, Bulou A, Buzaré J-Y, Emery J, Silly G (1998) AF fluoropolymer for optical use: spectroscopic and surface energystudies; comparison with other fluoropolymers. Eur Polym J 34(10):1457–1465. doi:10.1016/s0014-3057(97)00289-9

    Article  Google Scholar 

  35. Bratescu MA, Saito N, Takai O (2006) Treatment of immobilized collagen on poly(tetrafluoroethylene) nanoporous membrane with plasma. Jpn J Appl Phys, Part 1 45:8352–8357. doi:10.1143/jjap.45.8352

    Article  CAS  Google Scholar 

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Acknowledgment

We thank Kaiser Optical Systems for the allocation of a RamanRXN1™ system.

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Correspondence to Dieter Oelkrug or Rudolf W. Kessler.

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Oelkrug, D., Ostertag, E. & Kessler, R.W. Quantitative Raman spectroscopy in turbid matter: reflection or transmission mode?. Anal Bioanal Chem 405, 3367–3379 (2013). https://doi.org/10.1007/s00216-013-6719-2

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  • DOI: https://doi.org/10.1007/s00216-013-6719-2

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