Roberto Sáez-Hernández

University of Valencia | UV · Analytical Chemistry

The investigation of ancient artifacts is often constrained by their scarce availability and high protection and custody protocols. Among these, coinage represents an especially valuable kind-of-samples given their uniqueness and the subjacent information that is hidden behind their composition. Their analysis are often carried out using non-destru...

In this work, we present the results of the chemical, mineralogical and colorimetric characterization of the waterproofing mortars from the ancient cisterns of the Sagunto Castle (Valencia, Spain). The fortress presents 2500 years of human occupation and, given the lack of natural water sources, collecting and storing rain water was mandatory ever...

In this article, the detailed description of a smartphone-based analytical method to turn a smartphone into a colorimeter is described and applied to mural painting replicas. The method consists of a camera characterization process, to estimate CIELAB values from RGB camera responses, correcting for potential experimental interferences, like the ef...

In this article, the Islamic gold coins collections of the University of Valencia is studied for the first time for its elemental composition and colorimetric properties. To that end, non-destructive elemental analysis using energy-dispersive X-ray fluorescence is applied to obtain the coins’ elemental profile. Additionally, the colour of the coins...

A low-cost new instrument to carry out automated colorimetric analysis has been developed. The device consists of a carousel sampler, built by a 3D-printer, and a Raspberry Pi4-controlled signal measurement module based on the RGBC (red, green, blue and clear) responses of a TCS34725 color light-to-digital converter with IR filter. The device has b...

A digital image colorimetric approach was developed using a smartphone as a detection device to study acrylamide concentration in homemade toasts. Different slices of white bread were toasted, their resulting colour was captured with the smartphone, and the acrylamide concentration in the samples was determined by LC-MS/MS. From that information, a...

The characterization of red pigments in frescoes wall paintings has been of great interest for researchers to better understand raw material procurement dynamics, pigment receipts, stylistic evolution and to assess their conservation state. In this study a non-destructive colorimetric approach implementing a smartphone-based method was developed in...

In this work, an RPG video game is developed with the use of the RPG maker ® MZ software to help university/high-school students in reviewing mathematical concepts to apply them in the chemistry field. The video game is thus intended to prevent university/high-school mathematics/chemistry teachers from having to review concepts explained in previou...

Resumen: En este trabajo se ha desarrollado un método para cuantificar quinina mediante fluorescencia con Smartphone. El procedimiento implica solo la necesidad de una linterna de luz ultravioleta (396 nm), una caja de porexpán, una cubierta plástica con recubrimiento interno de terciopelo negro y un Smartphone. El método proporciona un límite de d...

In this work, a colorimetric analysis of adulterated tuna samples is carried out using both a spectroradiometer and a smartphone as capture devices. Yellowfin tuna (Thunnus albacares) slices were treated with nitrate and nitrite salts, as well as with two different vegetable extracts (beetroot and radish), and the resulting NO2⁻ and NO3⁻ concentrat...

A lab-made device was built to analyse phosphate in four different matrices using a smartphone as a capturing device.

A microporous material made of cyclodextrin units covalently immobilized into a silica network has found an innovative bioanalytical application in the sample clean-up and simultaneous isolation of three synthetic cannabinoids (ADB-CHMICA, MMB-CHMICA, and MDMB-CHMCZCA) from human oral fluid through solid-phase extraction. The subsequent quantitatio...

Debido a la pandemia provocada por el COVID-19, varias instituciones educativas se han visto obligadas a cerrar sus instalaciones, y los cursos prácticos -como las prácticas de laboratorio- son imposibles de realizar. El game-based learning se puede encontrar entre las muchas técnicas de aprendizaje digital, y consiste en enseñar los contenidos com...