A total analytical system featuring a novel solid-liquid extraction chamber for solid sample flow analysis

On-line microcolumn-based dynamic leaching method for investigation of lead bioaccessibility in shooting range soils

In this work, a miniaturized flow-through leaching test is presented for rapid screening of potential chemical extractants to explore the bioaccessibility of lead (Pb) in contaminated shooting range soils in Valkeala, Finland. The method combines the versatility of microcolumn-based extraction methods with on-line inductively coupled plasma optical emission spectrometry (ICP OES) analysis for expedient assessment of the magnitude of the bioaccessible pools and the leaching kinetics of lead from polluted soils under variable physicochemical scenarios. Acids and salt solutions were studied as potential extractants. The efficiency of the extractants relative to the initial total amount of lead in the soil sample (509 ± 21 mg/kg) were found to increase in the following order: 0.11 M acetic acid (55%) < 1 M MgCl₂ (58%) < 0.1 M NH₂OH·HCl (61%) < 0.1 M citric acid (93%) < 0.1 M HCl (96%). The proposed on-line microcolumn-based method was further explored for implementation of the modified BCR (now termed Standards, Measurements and Testing Programme, SM&T) sequential extraction procedure to avail the information about different fractions available in the solid sample, and validated by mass balance calculations. The equivalent sequential procedure in a batch format was then studied and compared against the on-line microcolumn extraction method. The on-line dynamic extraction system presented in this work accepts a substantial amount of sample (2.5 g) as compared to previous flow-through mini-column setups (generally accommodating < 0.25 g of sample), thus maintaining sample representativeness and fostering comprehension of the extraction patterns for non-homogenous soil materials. The use of cotton buds and Teflon membranes and holders in the microcolumn setup facilitates the repeatable flow-through leaching of trace elements and restrict formation of preferential channels. Monitoring of the leachable trace elements in real time delivers detailed insight into the ongoing extraction process and provides a time-saving assessment of potential chemical extractants.

An automated flow system for in-line extraction of proteins and separation of jacalin using a low-cost stationary phase

Lectins are carbohydrate binding proteins with many physiological and biotechnological applications. Isolation of proteins is normally time-consuming and encompasses multiple and, sometimes, complicated steps that hinder reproducibility and yield. Affinity chromatography is an efficient way to simplify and improve protein purification, however often requiring an expensive and fragile stationary phase. In this regard, automated flow-based systems minimize the time for extraction of species from solid samples without hindering the features of batch procedures. In this work, a new inexpensive affinity-based stationary phase was developed for in-line separation of jacalin, a galactose-binding lectin from jackfruit seeds. In the flow manifold, in-line extraction of proteins was also carried out with continuous monitoring using the spectrophotometric Biuret assay. For protein determination, linear response was observed from 3.0 to 15 g L^-1. The results of the analysis of protein extracts from jackfruit seeds obtained with the herein described procedure and batch procedure agreed with 95% confidence level. Quantitative extraction of proteins from jackfruit seed powder required recirculation of extraction buffer for 15 min through a lab-made polymethylmethacrylate (PMMA) column containing 200 mg of the crude seed powder. In the chromatographic step, jacalin was isolated after 300 s. Therefore, three essential steps for jacalin isolation were performed in one manifold in a fast way, minimizing sample consumption and solution handling. Additionally, the versatile and multi-task developed flow manifold can be useful for routine analysis and preparative procedures, being adaptable for the extraction and separation of other species from solid matrixes with continuous monitoring of the processes.