Hard Cap Espresso Machines in Analytical Chemistry: What Else?

Abstract

A hard cap espresso machine has been used in combination with liquid chromatography with molecular fluorescence detection for the determination of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils and sediments providing appropriate extraction efficiencies and quantitative results. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benz[b]fluoranthene, benz[k]fluoranthene, benz[a]pyrene, dibenz[a,h]anthracene, benz[ghi]perylene, and indeno[1,2,3-cd]pyrene were used as target compounds. It should be mentioned that the pairs benz[a]anthracene-chrysene and dibenz[a,h]anthracene-benz[ghi]perylene peaks coelute under the employed chromatographic conditions; thus, those compounds were determined together. PAHs were extracted from 5.0 g of soil, previously homogenized, freeze-dried, and sieved to 250 μm, with 50 mL of 40% (v/v) acetonitrile in water at a temperature of 72 ± 3 °C. The proposed procedure is really fast, with an extraction time of 11 s, and it reduces the required amount of organic solvent to do the sample preparation. The obtained limit of detection for the evaluated PAHs was from 1 to 38 μg kg(-1). Recoveries were calculated using clean soils spiked with 100, 500, 1000, and 2000 μg kg(-1) PAHs with values ranging from 81 to 121% and good precision with relative standard deviation values lower than 30%. The method was validated using soil and sediment certified reference materials and also using real samples by comparison with ultrasound-assisted extraction, as reference methodology, obtaining statistically comparable results. Thus, the use of hard cap espresso machines in the analytical laboratories offers tremendous possibilities as low cost extraction units for the extraction of solid samples.

Analytical Research Based on the Use of Low Cost Instrumentation

“…On the other hand, studies made at the end of the last century improved extraction and reaction steps by using ultrasound water-bath. 10 In recent years we have proposed the use of hard cup espresso machine to extract organic contaminants from solid samples 11 being confirmed that the use of a temperature around 72ºC degrees and a pressure of 19 bars can provide quantitative extraction of target analytes in only few seconds. Nowadays, the use of photo cameras and smartphones together with chemometric models permit to obtain general parameters 12 and specific characteristics of samples without using reagent and not damaging the studied products.…”

Development and Applications of Water‐based Extraction Methods in Natural Products Isolation Chemistry

“…Extraction pressure is controlled by both the sample particle size and the capsule membrane, with the semi-elastic nature of the capsule membrane (typically aluminium) providing back-pressure prior to its final rupture, which is claimed by one manufacturer to reach up to 19 bar. [21] Extractions employing hard cap espresso machines have utilised MeCN/H 2 O mixtures (up to 100% v/v), [22,23,24] EtOH/H 2 O mixtures (up to 80% v/v) [23,25,26] and neat isopropanol. [24] Natural Product Isolation via ASE Since its development in 1996, ASE using primarily water-based solvent systems (� 50% v/v H 2 O/organic solvent) for natural product isolation has been rather limited.…”

“…This includes the extraction of polycyclic aromatic hydrocarbons (PAHs) from soils and sediments. [22] PAHs, a class of particularly non-polar organic molecules containing fused aromatic rings, are present in the environment with these compounds regarded as carcinogenic, and/or mutagenic. A range of PAHs were analysed from the crude extracts using liquid chromatography-fluorescence detection (LC-FD), including anthracene (59), fluoranthrene (60), and pyrene (61).…”

Extraction Efficiency of a Commercial Espresso Machine Compared to a Stainless-Steel Column Pressurized Hot Water Extraction (PHWE) System for the Determination of 23 Pharmaceuticals, Antibiotics and Hormones in Sewage Sludge

“…Typically, modern espresso machines reach temperatures around 100 • C and operates at pressures of 15-20 bars. Substantial research has been done to better understand what parameters govern the extraction process of coffee with the aim of achieving a balanced coffee aroma [27][28][29][30], but commercial espresso machines have also been used to determine different contaminants such as polyaromatic hydrocarbons in soil [31], airborne pesticides in particulate matter trapped in filters [32] and polychlorinated biphenyls in soil [33]. In this work, a commercially available espresso machine was used for the extraction of APIs holding a variety of physicochemical properties from dewatered stabilized sewage sludge.…”