Rapid determination of Cu, Fe, Mg, Mn and Zn in wood pulp by direct sample insertion-inductively coupled plasma-optical emission spectrometry using a pyrolytically coated graphite sample probe

Abstract

A rapid method for screening wood pulp samples by direct sample insertion-inductively coupled plasma-optical emission spectrometry (DSI-ICP-OES) is described. Solid wood pulp samples were introduced directly into an inductively coupled plasma, using a pyrolytically coated graphite DSI sample probe, after in situ chemical treatment with HCl and NaF. Drying and ashing steps were performed by inductively heating the sample probe in the ICP coil prior to plasma ignition. The analysis time of the method from sample acquisition to analysis was of the order of several minutes per sample, as compared to several hours when conventional dissolution methods are used. Agreement with reference values for wood pulp samples ranged from 3.4±16% (absolute) for high-concentration analytes (Mg, Mn) and 1.7±50% (absolute) for low-concentration ones (Cu, Fe, Zn) using external standards. Precision ranged from 6±50% RSD and was highly dependent on the element and pulp sample studied. Absolute detection limits for the method were of the range of 50±1000 pg, translating into relative detection limits of 20±400 ppb based on a 2.5 mg pulp sample. The merits of using DSI-ICP-OES for the direct analysis of wood pulps, and of using a pyrolytically coated graphite probe for this type of application, are discussed.

A novel micro pressurized liquid extraction method for very rapid solid sample preparation

“…14 In this regard, efforts to miniaturize sample preparation methods have been benecial. 15,16 With respect to PLE, this has mainly been approached through modifying conventional PLE instrumentation to perform extractions on a smaller scale. For example, a miniaturized PLE sample cell has been used for extracting polychlorinated biphenyls from foodstuffs and it was found that just 3.5 mL of hexane was required to extract 100 mg samples in about 15 minutes.…”