Analytica Chimica Acta 402 (1999) 1–5 Urgent Letter Evaporative light scattering detector: a new tool for screening purposes S. Cárdenas, M. Gallego, M. Valcárcel ∗ Analytical Chemistry Division, Faculty of Sciences, University of Córdoba, E-14004 Córdoba, Spain Received 5 September 1999; accepted 5 September 1999 Abstract Continuous flow systems have easily been coupled to a evaporative light scattering detector for screening purposes. The interface was constructed by means of a high pressure line consisting of a high pressure pump and a high pressure six-port injection valve. This design allows sample preparation (clean-up and preconcentration) and separation to be done automatically. The universal response provided by the detector permits the screening of a variety of analytes in different samples. ©1999 Elsevier Science B.V. All rights reserved. Keywords: ELSD; Screening; Monosaccharides; Dissaccharides 1. Introduction The need for rapid analytical tools providing a re- liable yes/no response is growing as it is often the case that the amount of information gathered conven- tionally considerably exceeds that actually required for effective decision making. Screening systems act as filters and indicate whether the target analytes are present above or below a preset cut-off concentration. In most cases, only a small subset of samples pro- vides a ‘yes’ response and must thus be subjected to the conventional analytical process both to confirm the response of the screening system and to derive additional analytical information [1]. Therefore, the use of screening systems involves several advantages concerning reduction of costs, rapidity, simplicity and ∗ Corresponding author. Tel.: +34-957-218614; fax: + 34-957-218606 E-mail address: qa1meobj@lucano.uco.es (M. Valc´ arcel) minimisation of errors due to the delay between sam- pling and analysis. Continuous flow configurations can play a marked role in the development of these sys- tems, as they cover most of their requirements [2]. Evaporative light scattering detection (ELSD) is a powerful technique that can be applied in flow sys- tems to all solutes having lower volatility than the mobile phase. So it can be considered to offer a uni- versal response to all analytes except those having volatility higher than the mobile phase. It is based on light scattered from analyte particles when they pass through a light beam. The intensity of the scat- tered light depends on the size, shape and surface properties of the particle formed [3]. Its purpose is to complement UV absorptiometric detection of so- lutes when they do not absorb UV radiation or do so only at inconvenient wavelengths where sensitiv- ity and baseline stability during gradient elution are severely compromised. It also offers several advan- tages in comparison to the refractive index detector 0003-2670/99/$ – see front matter ©1999 Elsevier Science B.V. All rights reserved. PII:S0003-2670(99)00712-6