Tag: heavy metals

Development of a methodology for the rapid determination of trace amounts of lead in cosmetic raw materials

Development of a methodology for the rapid determination of trace amounts of lead in cosmetic raw materials

The study was conducted by an interdisciplinary team of researchers from the SOLARIS National Synchrotron Radiation Centre, AGH University of Krakow, the Institute of Physics of the Jagiellonian University, and an industrial partner, Inglot Sp. z o.o. The aim of this work was to develop a rapid and sensitive method for the determination of trace amounts of lead in raw materials with potential cosmetic applications. The feasibility of using energy-dispersive X-ray fluorescence excited by monochromatic synchrotron radiation (SR-XRF) for the quantitative analysis of samples with complex and unknown matrices was evaluated. The use of synchrotron radiation enabled the achievement of very low detection limits with minimal sample preparation and short measurement times, and the results were validated using the ICP-OES method.

Cosmetic products play a significant role in human life, and their importance continues to increase alongside economic development and improved accessibility for various social groups. However, the growing number of consumers is accompanied by increasing concerns regarding cosmetic safety, particularly with respect to the presence of heavy metals. In the European Union, cosmetic products are regulated under Regulation (EC) No. 1223/2009, according to which lead and its compounds are listed as prohibited substances. Due to natural processes and the ubiquitous presence of ultra-low concentrations of elements in the environment, achieving their complete absence is not feasible, which necessitates the use of reliable and sensitive analytical methods enabling their control at trace levels.

Despite the existence of national recommendations concerning permissible heavy metal contents in cosmetics, harmonised international standards are still lacking. For example, in the United States and Canada a limit of 10 μg/g of lead is recommended, while in Germany the recommended limit is 5 μg/g. Heavy metals, including lead, may enter the human body via oral, inhalation or dermal routes, leading to bioaccumulation and serious adverse health effects, such as DNA damage, disruption of enzymatic activity, or abnormalities in calcium metabolism. Particular attention is given to products applied in the vicinity of the mouth and eyes, due to the risk of ingestion and the increased permeability of the thin skin in these areas.

Read more on the SOLARIS website

Image: Samples of cosmetic raw materials in tablet form just before XRF analysis on the POLYX beamline

How much cadmium is contained in cocoa beans?

How much cadmium is contained in cocoa beans?

Cocoa beans can absorb toxic heavy metals such as cadmium from the soil. Some cultivation areas, especially in South America, are polluted with these heavy metals, in some cases considerably. In combining different X-ray fluorescence techniques, a team at BESSY II has now been able to non-invasively measure for the first time where cadmium accumulates exactly in cocoa beans: Mainly in the shell. Further investigations show that the processing of the cocoa beans can have a great influence on the concentration of heavy metals.

People have been harvesting the beans of the cocoa bush for at least 5000 years. They have learned to ferment, roast, grind and process the beans with sugar and fat to make delicious chocolates. Today, around five million tonnes of beans are on the market every year, coming from only a few growing areas in tropical regions.

Soul food chocolate

Chocolate is considered a soul food: amino acids such as tryptophan brighten the mood. Cocoa beans also contain anti-inflammatory compounds and valuable trace elements. However, cocoa plants also absorb toxic heavy metals if the soils are polluted, for example by mining, which can gradually poison groundwater and soils.

Where do the toxic elements accumulate?

An important question is,  where exactly the heavy metals accumulate in the bean, whether rather in the shell or rather in the endosperm inside the bean. From the harvest to the raw material for chocolate, the beans undergo many steps of different treatments, which could possibly reduce the contamination. And ideally the treatment could be optimised in order to make sure that the heavy metals are reduced but the desirable trace elements are retained.

Mapping the beans at BESSY II

A team led by Dr. Ioanna Mantouvalou (HZB) and Dr. Claudia Keil (TU Berlin/Toxicology) has now combined various imaging methods at the BAMline of BESSY II to precisely map the heavy metal concentrations in cocoa beans. They examined cocoa samples from a cultivation region in Colombia, which were contaminated with an average of 4.2 mg/kg cadmium. This is well above the European limits of 0.1-0.8 mg cadmium/kg in cocoa products.

Read more on the HZB website

Image: Cocoa beans are the main ingredients of chocolate, a famous “soul food”. However, cocoa plants also absorb toxic heavy metals if the soils are polluted. At BESSY II, a team has now mapped the local distribution of heavy metals inside the beans.

Credit: © AdobeStock