SAC Research Group
About the lab
Research at SAC team focuses on the design and synthesis of green tailored supramolecular solvents (SUPRAS) as an efficient alternative to petroleum-derived solvents in extraction processes. The tailored SUPRAS have unique features for increasing efficiency and selectivity in a profitable and sustainable way for the development of products and processes. Our developments focus on providing new solutions and tools in two major areas; the target and non-target analysis of organic contaminants in environmental, food and biological samples and the isolation of bioactive ingredients from plants, microalgae and agrifood industrial residues.
Featured projects (1)
Featured research (93)
The incidence of drug-facilitated sexual assault (DFSA) has dramatically increased in the last decades. Forensic analytical scientists continuously seek new methods and specimens to prove the incidence of intoxication for the judiciary system. Factors influencing sample selection include the ease of obtaining the samples and the window of detection of the drugs, among others. Both conventional (blood, urine) and non conventional specimens (hair, nails, fluids) have been proposed as suitable in DFSA cases. Reported sample treatments include a variety of liquid-liquid and solid-phase extraction as well as dilute-and-shoot procedures and microextraction techniques. Regarding analysis, liquid chromatography coupled to tandem mass spectrometry (LC MS/MS) has emerged as the preferred confirmatory technique, due to its sensitivity, selectivity, and wide-scope applicability. In this review, we critically discuss the most common specimens and sample treatments/analysis procedures (related to LC-MS/MS) that have been reported during the last ten years. As a final goal, we intend to provide a critical overview and suggest analytical recommendations for the establishment of suitable analytical strategies in DFSA cases.
Hair is becoming a main matrix for forensic drug analyses due to its large detection window compared to traditional matrices (i.e. urine & blood) and the possibility of establishing the temporal pattern of drug consumption. However, the extremely time- and solvent-consuming nature of conventional sample treatments render it difficult for routine use of hair analysis in forensics. In this paper, this drawback was intended to be addressed by the use of hexanol-based supramolecular solvents (SUPRAS) with restricted-access properties. The aim was to develop a fast and interference-free sample treatment workflow for the determination of opioids, cocaine, amphetamines and their metabolites in human hair. The main variables affecting the extraction were optimized and the method was validated following the European Medical Agency guideline. Major advantages of the proposed method were the straightforward sample preparation, which combines a high extraction yield (93-107%) and matrix effect removal (93-102 %SSE) in a single step, the high sample throughput, and the reduced volume of organic solvent required (100 µL of SUPRAS per sample), which makes sample treatment cost-effective and eco-friendly. Method quantification limits were lower enough for all the target drugs (0.5-1.1 pg mg⁻¹) to allow their quantitation in human hair routine analyses. The method was successfully applied to the determination of drugs of abuse in a human hair control sample.
Recent research findings have confirmed the presence of illicit drugs in tap water from some European Union (UE) member states. Contaminants in tap water come directly from drinking water sources such as rivers or lakes owing to inefficient removal at wastewater treatment and water purification plants. This work was aimed at setting a starting point for assessing the health risks of exposure to twelve drugs of abuse through consumption of tap water in the European population. For this purpose, a method using supramolecular solvents (SUPRAS) was developed to extract drugs in the opioid, amphetamine, cocaine and cannabinoid groups from tap water for their determination by liquid chromatography–tandem mass spectrometry (LC–MS/MS). A total of 119 tap water samples were collected from eight EU countries for analysis. Seven drugs were found at concentrations from 0.3 to 340 ng/L in 72 of the samples (60.5%). The mean exposure to the drugs through consumption of tap water was calculated to be 0.0064–3.531 ng/kg·day for adults and 0.0247–6.7580 ng/kg·day for children, whereas that resulting from dermal contact was estimated to be 4–7 orders of magnitude lower. Exposure values were compared with the minimum required performance levels (MRPL) for the drugs in urine set by the World Anti-Doping Agency (WADA). Based on the results, a need clearly exists for further research into the adverse effects on health of inadvertent, sustained exposure to low doses of drugs of abuse.
Methanetriyl-pi hydrogen bonding (CH-π HB) in nonpolar domains of supramolecular nanostructures is proposed here as a new mechanism to increase the extraction efficiency of aromatic compounds. The approach is illustrated by the extraction of priority carcinogenic polycyclic aromatic hydrocarbons (CPAHs) in soils using supramolecular nanostructures of carboxylic acids with nonpolar domains consisting of hydrocarbon chains (C6-C10) dispersed in tetrahydrofuran (THF). The high concentration of CH-groups available in the supramolecular nanostructures (38.7-47.3 M) enabled the efficient extraction of CPAHs (recoveries between 89 and 106%), using a supramolecular solvent (SUPRAS) volume/soil amount ratio of 1.5 and a simple and quick procedure (stirring for 15 min and centrifugation for 10 min). SUPRAS extracts were directly analysed by liquid chromatography-fluorimetry (LC-FL). No sample clean-up or solvent evaporation was required. Optimization of the composition of the nonpolar domains of the SUPRASs was carried out varying the length and concentration of the hydrocarbon chain of the carboxylic acid and the concentration of THF. Method detection limits were in the interval 0.07-0.4 µg kg¹. The relative standard deviations (n=18, CPAH concentration = 300 µg kg¹), obtained under repeatability and reproducibility conditions, varied within the ranges 2.8-5.4% and 4.3-8.8%, respectively. The accuracy of the method was proved by analysing a certified reference material (CRM) from an industrial soil, contaminated with priority CPAHs at concentrations at the mg kg¹ level (BAM-U013c). The concentration of CPAHs found in soils taken in Southern Spain varied in the range 0.51-49 µg kg¹. The results here obtained demonstrate that CH-π HB is a valuable mechanism for increasing the extraction of aromatic compounds from soils.
Bisphenol A (BPA) and alternative bisphenols are widely used in the industrial production of polycarbonates and resin polymers. Adverse effects on human health have been described for BPA and owing to the structural similarity of alternative bisphenols and derivatives, a similar toxicity profile is expectable. Dust can act as a sink for bisphenols owing to the large surface area to mass ratio. Human risk exposure to bisphenols via indoor dust has been widely assessed in the last decade. The environmental conditions inside greenhouses, among other factors, facilitate that chemicals are released from greenhouse building materials to dust. This study aims to explore for the first time the potential of greenhouse dust as a new source of bisphenols for human exposure. For this purpose, a supramolecular solvent-based method was applied to the extraction of twenty-one bisphenols from greenhouse dust, prior to their determination by liquid chromatography–tandem mass spectrometry. Nineteen bisphenols were found in the five greenhouse dust samples analysed, with concentrations ranging from 5275 ng g ⁻¹ (BPA) to 0.25 ng g ⁻¹ (trichlorobisphenol A). The average daily dose (ADD) via dust ingestion for bisphenol compounds was calculated, in order to estimate the occupational exposure for inadvertent dust ingestion. Despite the calculated ADD value for BPA (47.81 ng kg ⁻¹ day ⁻¹ ) being below the tolerable daily intake proposed by EFSA (4·10 ³ ng kg ⁻¹ day ⁻¹ ), this value was considerably higher than those previously reported for indoor dust, which brings to light the importance of considering greenhouse dust as bisphenols source of exposure for greenhouse workers. Graphical abstract