Analytica Chimica Acta 554 (2005) 207–217 Application of infrared spectroscopy and multivariate quality-control methods in PVC manufacturing Lidia Maria Bodecchi a , Marina Cocchi a , Marcello Malagoli b , Matteo Manfredini a , Andrea Marchetti a,∗ a University of Modena and Reggio Emilia, Department of Chemistry, via G.Campi 183, 41100 Modena, Italy b Gambro Dasco S.p.A., via Modenese 30, 41036 Medolla (Modena), Italy Received 19 January 2005; received in revised form 8 July 2005; accepted 1 August 2005 Available online 19 September 2005 Abstract This work aims at exploring the potentiality of the Fourier transform IR spectroscopy (FTIR) to study the effects that can be generated on plastic materials based on poly(vinyl chloride) (PVC) used for extra-corporal medical disposables, after industrial processes such as extrusion, sterilization and conservation. In particular, FTIR equipped with a single attenuated total reflection accessory (ATR) mounted on an infrared microscope (Mic-IR) has been used. At the same time, this paper proposes a quality-control method for semi-finished blood circuits’ components, based on the chemometric evaluation of surface-selective spectroscopic signals, i.e. Mic-IR/ATR spectra. Results suggest that IR spectroscopic technique coupled with a multivariate approach might represent a simple and powerful method for quality control of industrial processes. © 2005 Elsevier B.V. All rights reserved. Keywords: PVC; Industrial manufacturing; FTIR/ATR; Quality-control method; Multivariate control charts; 3-way PCA 1. Introduction Poly(vinyl chloride) (PVC) is one of the most used thermo- plastic polymer for biomedical disposable devices owing to its compatibility with a large number of additives (i.e. plasticizers, impact modifiers, heat stabilizers), its mechanical properties that can be modulated in a wide range, yielding from rigid to flexi- ble end products and, at last but not less important, owing to its capability to produce relatively low-cost materials [1]. This work is focused on the description and the evaluation of the effects that can be generated on plastic materials used for extra-corporal medical disposables following their industrial processing. Nowadays, the industrial manufacturing of poly- meric biomaterials is a complex framework involving several different steps. From the blending of raw materials to semi- finished products, passing through extrusion and/or moulding processes and arriving to packaging and sterilization steps, the finished products obtained become ready to start either their use-life or a proper period of shelf-life. Each of the aforemen- ∗ Corresponding author. Tel.: +39 059 2055028; fax: +39 059 373543. E-mail address: marchetti.andrea@unimore.it (A. Marchetti). tioned processing steps could be suspected to promote thermal or chemical degradation events on the materials. Thus, the knowl- edge of the various effects on polymers’ properties, which might be carried on by their own production conditions, is of critical importance for the materials and the medical devices research and production fields. Hence, this work is focused on three of the above-mentioned industrial processes, namely extrusion, steril- ization and conservation steps. Analytical methods based on spectroscopic techniques, such as UV–vis, near- (NIR) and mid- (MIR) infrared and Raman spectroscopy can all provide a rich source of information about chemical properties of polymeric matrices likely to undergo some changes during industrial processing. Moreover, such tech- niques might offer an interesting alternative to classical process analytical methods, such as chromatographic techniques being quick, robust, nondestructive and first of all applicable in- or on-line [2]. The implementation of spectroscopic techniques to obtain real-time information about process has been adopted in a number of industrial fields such as food analysis [3] and pharmaceuticals [4]. A lot of applications for the monitoring of batch process, polymers melt extrusion and blending have been presented in the literature. On-line UV–vis spectroscopy was used for monitoring chemical batch reaction [2]. In-line 0003-2670/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.aca.2005.08.023