Fast screening of terpenes in cosmetics by fluorescence quenching of the bovine serum albumin-fluorescein system confined in a single drop

By -

The presence of fragrances in cosmetics could be a problem of health concern, since some of the employed chemicals may induce asthma, migraines headaches and other adverse effects. In fact, the European Union has established a list of 26 potential allergens used as fragrances, 23 of them being volatiles terpenes. These substances may act also at low concentrations and therefore their analytical monitoring is desirable, even in theoretically fragrance-free products. Researchers from the University of Vigo (Spain) have recently presented in a research article, published in Analytica Chimica Acta, a rapid screening method for terpenes in cosmetics. This approach is based on the potential fluorescence quenching that these hydrophobic compounds induce in the bovine serum albumin (BSA)- fluorescein (F) system.

The potential quenching effect of terpenes in BSA-fluorescent indicator systems is well reported in the literature. However, this general approach does not allow the determination of terpenes at low concentrations. This shortcoming has been overcome confining the BSA-F system in an aqueous drop which is exposed to the headspace of the sample (see Figure 1), after a simple preparation process. The headspace single drop microextraction step provides a preconcentration of the targets improving the sensitivity of the determination, providing a limit of quantification as low as 0.57 µg/g.

Single drop microextraction using bovine serum albumine-fluorescein sytem as probe

This screening method provides a general index of terpenes in the cosmetic sample thanks to the similar quenching effect observed for the tested analytes. It is simple (it only requires a dissolution of the sample in a ethanolic mixture) and rapid (it spends only 10 min) and it can be used in routine analysis with excellent precision.

For further details, readers are referred to the original article. They will find there the complete procedure, the optimization process as well as the analytical characterization of the final approach.

Link to the article: Fast screening of terpenes in fragrance-free cosmetics by fluorescence quenching on a fluorescein–bovine serum albumin probe confined in a drop

Comments

Post a Comment

Popular posts from this blog

Gold coated magnetic beads for electrochemical detection

By -
Image
This post summarizes an interesting article, recently accepted for publication in Analytical Chemistry, which presents an innovative use of magnetic beads. Researchers from the Osaka Prefecture University at Japan have proposed the synthesis of magnetic microbeads covered with a smooth gold layer that are used for the electrochemical detection of streptavidin (1). The synthesis, which is deeply described in the manuscript, consists of three well defined steps. First of all, the magnetic beads are introduced in a colloidal gold dispersion containing Au-nanoparticles (Au-NPs). Thanks to the opposite zeta potential of both materials (microbeads are negatively charged while Au-NPs present a positive charge), their assembly takes place by electrostatic interactions. However, the Au-NPs are not connected to each other and therefore the electrical resistance of the microbeads is too high. In a second step, the modified microbeads are dispersed in an aqueous medium containing HAuCl 4 as
Read more

Fabric phase sorptive extraction: a new generation green sample preparation strategy

By -
Image
by Dr. Abuzar Kabir, International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA Fabric phase sorptive extraction (FPSE), the most recent member of the sorptive microextraction family, has innovatively incorporated both solid phase microextraction (SPME) and solid phase extraction (SPE) techniques into a single technology platform. FPSE utilizes permeable natural/synthetic fabrics e.g., cotton, polyester, fiber glass supports to chemically bind sol-gel hybrid inorganic-inorganic sorbents. A 5 cm2unit of coated fabric (2.5 cm x 2.0 cm) is typically used as the extraction media which can be inserted directly into the sample container. Extraction of the analytes is generally expedited by using a magnetic stir bar to diffuse the analyts into the sample matrix so that rapid mass transfer from the sample matrix to the extraction medium takes place.Once the mass transfer equilibrium between the FPSE media and
Read more

Highlighted articles (November 27th, 2015)

By -
Image
We recommend the following articles that deal with different aspects related with sample preparation. 1. Application of graphitic sorbent for on-line microextraction of drugs in human plasma samples . Graphitic carbon has a great potential as sorbent since it may develop different interaction chemistries with target compounds. Commercial graphitic carbons like graphitized carbon black or porous graphitic carbon presents some disadvantages including a lack of mechanical stability or a high retention (almost irreversible) of some analytes. These shortcomings are faced in this article where a new carbon material is presented. The new material is based on the deposition of a graphitic carbon layer over an inert substrate like alumina. This combination increases the mechanical strength which is key for chromatographic uses. The material has been packed in a lab made microextraction in packed sorbent (MEPS) device and it has been applied for the extraction of ropivacaine and lidocaine f
Read more