Reference measurements of mercury species in seafood using isotope dilution inductively coupled plasma mass spectrometry

Species-specific isotope dilution inductively coupled plasma mass spectrometry (SS ID ICP-MS) and high-performance liquid chromatography (HPLC) were used to obtain accurate and SI traceable results for methyl mercury in seafood samples such as clam, oyster and fish homogenate. The mass fractions of (62.3 ± 2.3) μg kg⁻¹, (5.44 ± 0.36) μg kg⁻¹ and (531 ± 19) μg kg⁻¹ were obtained for MeHg (as Hg) in IAEA-461, IAEA-470 and IAEA-476, respectively. Direct isotope dilution mass spectrometry was performed for total mercury content then the content of inorganic mercury in selected samples was obtained by calculation. It was found that the content of inorganic Hg in IAEA-461, IAEA-470, and IAEA-476 was as: 328 μg kg⁻¹, 16 μg kg⁻¹, and 62 μg kg⁻¹, respectively. Mathematical modelling of analytical procedure and evaluation of all parameters influencing final results were adequate for validation of measurement procedure, establishing traceability and estimating expanded uncertainty. Developed procedures were successfully applied in the characterization process of fish homogenate candidate reference material and in the calculation of assigned values in the frame of IAEA-476 inter-laboratory comparison study. Compatibility between obtained results and those derived from the certification campaign, organized by International Atomic Energy Agency on the same sample matrix (<2.6 % difference) further validated performed ID ICP-MS protocols.     

Distribution of essential and non-essential elements in rice located in a Protected Natural Reserve “Marjal de Pego-Oliva”

Anthropogenic agronomic practices could negatively affect the agricultural soil which is the main source for inorganic arsenic (i-As) contamination in rice fields due to flooding. The presence of essential elements could be impacted by food industry units operations. The aim of this study was to evaluate the effect of husking and polishing on mineral essential elements and inorganic As species in rice from Protected Natural Reserve “Marjal de Pego-Oliva”. The amount of all studied elements was significantly affected by husking (a decrease of Ca, Na and Pb, 360 to 101 mg kg⁻¹, 202 to 46.9 mg kg^-1 and 17.9 to 5.70 μg kg⁻¹, respectively) and by polishing (a reduction of Na, Mg, P, K, Ca and Cu, 46.9–26.8 mg kg⁻¹, 1600 to 481 mg kg⁻¹, 4050 to 1530 mg kg⁻¹, 2780 to 882 mg kg⁻¹, 101 to 53.7 mg kg⁻¹, and 3600 to 2840, μg kg⁻¹, respectively).The replacement of white rice (WR) to brown rice (BR) could enhance the daily dietary intake of essential elements to reach the dietary reference values and the maximum i-As (40.9 and 44.9 i-As μg kg^-1 for BR and WR, respectively) was below the maximum level recently established by European Food Safety Agency.     

Total Mercury Content—Fish Weight Relationship in Swordfish (Xiphias gladius) Caught in the Southwest Atlantic Ocean

The total mercury content in the edible part of swordfish (Xiphias gladius) was determined in 192 specimens ranging from 10 to 412 kg, in the period January 1997–December 1999. Total mercury values between 0.04 and 2.21 mg kg⁻¹, with a mean value of 0.62±0.35 mg kg⁻¹, were obtained. Data were analyzed in two subsets. One of them, for specimens under 100 kg, yielded a mean value for total mercury content of 0.53±0.02 mg kg⁻¹, and the other, for specimens above 100 kg, had a mean value of 0.94±0.06 mg kg⁻¹. The existence of these subsets of data is related with the rate of mercury incorporation into swordfish flesh, in accordance with a potential model for total mercury bioaccumulation. Swordfish weighing below 100 kg can be considered safe for human consumption, according to international regulations.     

Exposure to nickel through commercial premade baby foods: Is there any risk?

A study was performed to evaluate the risk regarding the presence of nickel in commercial premade baby foods: 26 ready meals, 31 fruits, 8 deserts and 20 paps. The analytical methodology used for the determination of nickel was dry ashing followed by graphite furnace atomic absorption spectrometry. Method detection limit (12.5 μg kg⁻¹) was obtained through a matrix matched calibration curve, using a nickel free commercial ready meal (meat).The results showed that 78 (91.8 %) samples contained nickel, with values up to 225.7 μg kg⁻¹. The group with the highest average concentration was the fruits (50.1 μg kg⁻¹) followed by the ready meals (40.2 μg kg⁻¹). Samples from organic farming presented higher detection frequency and average concentration (54.7 μg kg⁻¹) than the others. Using the average results, the tolerable daily intake proposed by EFSA (2.8 μg kg⁻¹ b.w.) was surpassed for the 2 year old age group, with daily ingestions up to 3.1 μg kg⁻¹ b.w.. This results highlight the risk promoted by the nickel present in commercial premade baby food.     

137Caesium, 40Potassium and potassium in raw and deep-oil stir-fried mushroom meals from Yunnan in China

A number of wild, edible mushroom species (Baorangia bicolor, Boletus calopus, Boletus obsclereumbrinus, Butyriboletus roseoflavus, Rubroboletus sinicus, Rugiboletus extremiorientalis and Xerocomus sp.) were collected in 2017, from Yunnan (Yuxi prefecture) in SW China. Samples of raw and stir-fried pools of these specimens were analysed for radioisotopes ¹³⁷Cs (caesium) and ⁴⁰K (potassium), and for total K concentrations. On a whole (wet) weight (ww) basis, ¹³⁷Cs activity ranged from < 0.10 to 0.75 Bq kg⁻¹ for raw, and from 0.5 to 4.4 Bq kg^-1 in stir-fried mushrooms. Radiopotassium (⁴⁰K) activity ranged from 57 to 96 Bq kg⁻¹ ww for raw, and 170 to 370 Bq kg⁻¹ ww for stir-fried mushrooms, while the corresponding concentration ranges for total K were 2100–3400 mg kg⁻¹ ww (mean: 2800 ± 3900 mg kg⁻¹ ww), and 6000–13000 mg kg⁻¹ ww-(mean: 8700 ± 2100 mg kg⁻¹ ww), respectively. This data indicates that mushrooms from this region show negligible ¹³⁷Cs contamination with evidently higher activity levels of ⁴⁰K. The deep oil stir-frying process results in enrichment in the resulting meals for all three determinants. 100 g meal portions showed ¹³⁷Cs activity in the range < 0.08 to 0.44 Bq 100 g⁻¹ ww (mean 0.15 ± 0.12 Bq 100 g⁻¹ ww), and ⁴⁰K activity from 16 to 37 Bq 100 g⁻¹ ww (mean 24 ± 6 Bq 100 g⁻¹ ww). The consequent exposure from ⁴⁰K contained in a single 100 g serving and weekly (100 g x7) servings was equivalent to radiation doses in the range of 0.099 to 0.23 μSv and 0.68–1.6 μSv per capita (means 0.15 ± 0.04 and 1.1 ± 0.3 μSv). This is equivalent to doses in the range of 0.0017 to 0.0038 μSv kg^-1 bm day^-1 and 0.011 to 0.027 μSv kg^-1 bm week^-1 respectively (mean values of 0.0025 ± 0.006 μSv kg^-1 bm day^-1and 0.018 ± 0.004 μSv kg^-1 bm week^-1). Analogically to the annual ¹³⁷Cs radiation exposure resulting from high rates of annual consumption (20–24 kg per capita), the estimated annual dose of radiation from ⁴⁰K would range from 0.34 up to 0.92 μSv kg^-1 bm (mean 0.60 μSv kg^-1 bm). Thus in practice, high annual consumption rates of wild, stir-fried mushrooms as seen in Yunnan, would result in negligible internal doses from decay of artificial ¹³⁷Cs, relative to that from natural ⁴⁰K. The 100 g servings also contained between 590–1300 mg K making this local food one of the top dietary sources of nutritionally important potassium for local consumers.     

Assessment of Lead and Cadmium Pollution in Soil and Wild Plants at Different Functional Areas of Sialkot

Heavy metal pollution is a great hazard to the environment that enters the ecosystem through different natural and anthropogenic sources. A study was performed to evaluate concentrations of Cd and Pb in selected plants, Ricinus communis and Parthenium hysterophorus, and soils from different functional sites in Sialkot. Maximum fresh and dry weights of R. communis were recorded from control and field sites. Highest concentrations of Cd in P. hysterophorus (33.5 mg kg⁻¹) and R. communis (24.36 ± 2.83 mg kg⁻¹) were recorded at residential and industrial sites, respectively. However, road site samples showed maximum concentrations of Pb both in R. communis (9.06 ± 0.35 mg kg⁻¹) and P. hysterophorus (7.90 ± 0.36 mg kg⁻¹). Soil from the road site were found to be highly acidic (pH 4.75 ± 0.04), while the field site showed highest EC (494 ± 3.60) and TDS (509 ± 3.00) values. Generally, there were reductions in chlorophyll a and carotenoids, but an increase in chlorophyll b was observed in both plants at all sites compared to the control.

     

Determination of Se content of 78 sesame accessions with different geographical origin

Selenium (Se) is an essential trace element for human health and plays an important role in fundamental physiological functions. Se accumulates in sesame seeds and this situation may differ between genotypes. Determination of Se content in food is very important because there is a narrow margin of safety between an adequate amount and overconsumption. The purpose of this study was to evaluate the variability in Se content among different sesame accessions from Turkey (12 sesame accessions) and 22 other countries from four continents (Asia, Africa, Europe and America). The determination of total Se in seed was performed with an atomic absorption spectrometer. The Se content of sesame seeds samples exhibited a wide range i.e. 0–9.32 mg kg⁻¹, with an average value of about 2.29 mg kg⁻¹. The accession India 1 had the highest Se concentration. The mean Se contents of sesame from 23 countries varied between 0.24–8.31 mg kg⁻¹ and with an average value of about 2.29 mg kg⁻¹. Sesame breeders can use the results of the present study to further the breeding programs for the development of new biofortified varieties.     

Concentrations and health risk assessment of total mercury in canned tuna marketed in Southest Brazil

The aim of this research was to determine total mercury (Hg) content in 69 canned tuna of 13 brands marketed in southwest Brazil. All values are reported in μg.g⁻¹ wet weight basis. Potential health risk was estimated on the basis of mercury concentration and average consumption (175 g/per week) of fish in Brazil comparing to PTWI of 1.6 μg.kg⁻¹ (FAO/WHO, 2010). A large variation in the concentration of mercury in different species was observed. Mean mercury concentration was 0.256 ± 0.215 μg.g⁻¹ with a highest value of 1.060 μg.g⁻¹ in a single can. In general average concentration was below the legislation of 1.0 μg.g⁻¹ for predatory species (BRASIL, 2010). Estimate weekly intake (EWI) varied 0.2–1.7 μg.kg⁻¹. For the analyzed brands and Brazilian fish consumption, no human health risk is likely to occur. However one brand was higher than PTWI of 1.6 μg.kg⁻¹ showing no safety for specific risk group. Further studies including specific data on canned tuna consumption in specific populations will be needed as well as the fish type, fish size and fishing location.     

Determination and chemometric evaluation of the mineral profile of maize flours

Maize flour is a food rich in nutrients important for the proper functioning of the human body. Nevertheless, for the determination of metals in maize flour there are few studies, which raise concern about quality and its mineral composition for consumption. In this work, it was evaluated the concentration of essential (Ca, Cu, Fe, Mn, Mg, Cr and Zn) and non-essential (Cd and Cr) metals in yellow and white maize flour samples produced in Paraná State - Brazil. For this purpose, it was performed a sample treatment employing wet digestion in a digester block and determination of metals by atomic absorption spectrometry (AAS). The highest concentrations found in the flour were Ca (55.4 mg kg⁻¹) and Mg (86.9 mg kg⁻¹) and the lowest concentrations were Cr (0.11 mg kg⁻¹) and Cd (0.01 mg kg⁻¹). In yellow and white maize flour the highest concentration was for Mg, 81.5 mg kg⁻¹and 98.4 mg kg⁻¹, respectively. Principal component analysis (PCA) showed that some samples had a similar mineral profile, such as the relationship with the place of origin of the cereal.     

Lead,cadmium and mercury in canned and unprocessed tuna: six-years monitoring survey,comparison with previous studies and recommended tolerable limits

Fishery products, in particular those belonging to tuna species, widely present in the human diet, may represent a toxicological issue because of the level of contamination by heavy metals (e.g., lead, cadmium and mercury) and the average per capita consumption. Control of food safety is one of the pillars to the public health safeguard, therefore the official laboratories are in charge of checking the compliance of food products with quality standards for these toxic elements.. From 2014 to 2019, 108 tuna samples, canned or unprocessed, were checked at the laboratory of the Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata (Italy). One canned tuna was non-compliant for cadmium (0.22 mg kg^-1), and twelve fresh tuna samples (11% of total) showed mercury content above the permitted level. Mean mercury concentrations in fresh and canned tuna (0.517 and 0.207 mg kg^-1, respectively) confirm that this element represents a serious toxicological issue. Exposition to mercury, and markedly in its organic form, due to tuna consumption, was found to be significant and may pose a risk for the most sensitive consumer groups (i.e., children).     

Aluminium in infant foods: Total content,effect of in vitro digestion on bioaccessible fraction and preliminary exposure assessment

The objective of this study was to determine the total concentration and bioaccessible fraction of aluminium (Al) in 95 different baby food samples and estimate the exposure assessment. Total Al content was determined following oxidative microwave digestion by inductively coupled plasma optical emission spectrometry. An in vitro digestionmethod was optimized to evaluate the bioaccessible fraction. Total concentration and bioaccessibility varied according to the sample composition (saltypurees, fruit purees, infant drinks and petitsuisse). Petit suisse, soy-based drink and salty puree samples presented the highest total Al concentrations of 4170 μg kg⁻¹, 2860 μg kg⁻¹ and 2760 μg kg⁻¹, respectively. Bioaccessiblefraction varied from 0.5%–48% according to their composition.Exposure to Al was estimated and compared with the tolerable weekly intakes currently established. The results showed that the consumption of 3 portions/day of soy-based drink along the week could represent a concern.     

Essential and non-essential elements in Brazilian infant food and other rice-based products frequently consumed by children and celiac population

Rice and its derivatives are important source of essential and non-essential elements. Essential elements as cobalt (Co) and selenium (Se) are vital for human homeostasis. However, non-essential elements such as arsenic (As), cadmium (Cd) and lead (Pb) may be present in rice-based food and consequently, people can be exposed—especially children and the celiac population. This study aimed to determine essentials and non-essentials elements in rice-based products and baby food and also to evaluate nutritional risk by estimating the daily intake of non-essential elements. Regarding essential elements, Co and Se presented the highest concentrations in rice flour (56 μg kg⁻¹) and porridge (254 μg kg⁻¹), respectively. For non-essential elements, the highest concentrations of As, Cd and Pb were 104 μg kg⁻¹ (porridge), 16 μg kg⁻¹ (flour), and 188 μg kg⁻¹ (bread), respectively. Total As concentration in Brazilian rice-based baby food was <29 μg kg⁻¹. However, As-speciation revealed inorganic-As (i-As) as the main specie. The highest estimated daily intake of Cd, Pb and i-As were 1.37 (rice-based baby food); 10.39 (pasta); and 3.34 (pasta) μg d⁻¹, respectively. Therefore, continuous food monitoring for nutritional and toxicological purpose is necessary, especially concerning these particular populations and discussions for maximum levels of non-essential elements.     

Preferential Liver Accumulation of Mercury Explains Low Concentrations in Muscle of Caiman yacare (Alligatoridae) in Upper Amazon

Caiman yacare is considered one of the top predators in the Amazon basin, and understanding pollutant distribution within its tissues may help its sustainable management. As a top predator, C. yacare should have the highest mercury concentrations, but has lower Hg concentrations than carnivorous fish (Rivera et al. 2016), which are part of their diet. We compared total Hg among liver, kidney, fat, and muscle of C. yacare, and whether trends in the distribution of Hg among tissues were like other crocodilians, aquatic birds, omnivorous, and carnivorous fish. Fat had the lowest concentrations (0.025 ± 0.03 mg kg⁻¹) followed by muscle (0.15 ± 0.06 mg kg⁻¹), kidney (0.57 ± 0.30 mg kg⁻¹) and liver (1.81 ± 0.80 mg kg⁻¹). Such preferential accumulation makes C. yacare meat a safer alternative for human consumption than carnivorous fish. The relation between Hg accumulation in liver and muscle is highest in crocodilians, which has evolutive and environmental implications.

     

Assessing sialic acid content in food by hydrophilic chromatography-high performance liquid chromatography

We have established a novel hydrophilic chromatography (HILIC)-high performance liquid chromatography (HPLC) method to assess sialic acid content in food products. Single-factor and response surface methodologies (RSM) were used to systematically optimize the hydrolysis conditions of the food samples to extract the maximum amount of sialic acid. Chromatographic conditions were also adjusted. In foods containing sialic acid, we observed a strong linear relationship between sialic acid and peak area, ranging from 5 to 100 μg/mL (R² = 0.9998). The lowest detectable sialic acid concentration (RSN = 3) was 0.2 μg mL⁻¹, and the method detection limit was 0.02mg kg⁻¹. Sample recovery ranged from 95.85% to 99.78%, with an RSD of 1.46% (n = 6). Thus, the described method can be applied to the study of sialic acid content in foods.     

Effect of the number of frying cycles on the composition,concentrations and risk of polycyclic aromatic hydrocarbons (PAHs) in vegetable oils and fried fish

The use of the same batch of oil for deep-frying on several occasions is a common practice. This study sought to determine the effects of repeated frying cycles on the composition, concentrations and risk of polycyclic aromatic hydrocarbons (PAHs) in six types of vegetable oils and the samples of fish fried therein. The PAH concentrations in the oils were measured before use and after each of three successive cycles of frying. Fish was fried at each time of use of the oils and, also, monitored for their PAH content. The PAH content in all samples was determined by gas chromatography-mass spectrometry (GC–MS). The concentrations of Ʃ22 PAHs in the unused oils ranged from 43.3–2107 μg kg⁻¹, while those in the used oil ranged from 40.8–4090 μg kg⁻¹. There were significant changes (p < 0.05) in the concentrations and composition of PAHs with respect to vegetable oil types and number of frying cycles. The cancer risk values for the vegetable oils (10⁻⁴ to 10⁻⁵) after three frying cycles exceeded the acceptable risk value of 10^-6 indicating a probable lifetime carcinogenic risk. However, adverse non-carcinogenic risks through consumption of these oils and fried fish were low.     

Determination of inorganic arsenic in Argentinean rice by selective HGAAS: Analytical performance for paddy,brown and polished rice

Inorganic As (iAs) species require strict monitoring in foodstuff due to their toxicity. Rice is of particular concern, with recent legislations establishing limits for these species. In this work we develop a method based on selective hydride generation atomic absorption spectrometry (HGAAS) for the determination of iAs in different types of rice (polish, parboiled, brown and paddy rice). The multivariate design of experiments used for optimization showed interactions between different factors involved in hydride generation. Matrix effects were systematically studied, where the flow rate of the carrier gas proved to be a critical parameter for the minimization of matrix interferences. Nevertheless, matrix-matching was found to be necessary for accurate quantification of paddy rice samples. Comparison of the iAs concentrations obtained by HGAAS and HPLC-ICP-MS showed non-significant differences between the methods. Analysis of 86 rice samples from the province of Entre Ríos showed relatively low concentrations of iAs (<282 μg kg⁻¹ for paddy rice and <120 μg kg⁻¹ for polished rice), regardless of total As concentrations (which ranged from 63 μg kg⁻¹ to 932 μg kg⁻¹), suggesting that the rice analyzed tends to accumulate As in its organic forms.     

Assessment of Heavy Metal Pollution in Republic of Macedonia Using a Plant Assay

Different plant organs (leaves, flowers, stems, or roots) from four plant species—Urtica dioica L. (Urticaceae), Robinia pseudoacacia L. (Fabaceae), Taraxacum officinale (Asteraceae), and Matricaria recutita (Asteraceae)—were evaluated as possible bioindicators of heavy-metal pollution in Republic of Macedonia. Concentrations of Pb, Cu, Cd, Mn, Ni, and Zn were determined in unwashed plant parts collected from areas with different degrees of metal pollution by ICP-AES. All these elements were found to be at high levels in samples collected from an industrial area. Maximum Pb concentration was 174.52 ± 1.04 mg kg⁻¹ in R. pseudoacacia flowers sampled from the Veles area, where lead and zinc metallurgical activities were present. In all control samples, the Cd concentrations were found to be under the limit of detection (LOD <0.1 mg kg⁻¹) except for R. pseudoacacia flowers and T. officinale roots. The maximum Cd concentration was 7.97 ± 0.15 mg kg⁻¹ in R. pseudoacacia flowers from the Veles area. Nickel concentrations were in the range from 1.90 ± 0.04 to 5.74 ± 0.03 mg kg⁻¹. For U. dioica leaves and R. pseudoacacia flowers sampled near a lead-smelting plant, concentrations of 465.0 ± 0.55 and 403.56 ± 0.34 mg kg⁻¹ Zn were detected, respectively. In all control samples, results for Zn were low, ranging from 10.2 ± 0.05 to 38.70 ± 0.18 mg kg⁻¹. In this study, it was found that the flower of R. pseudoacacia was a better bioindicator of heavy-metal pollution than other plant parts. Summarizing the results, it can be concluded that T. officinale, U. dioica, and R. pseudoacacia were better metal accumulators and M. recutita was a metal avoider.     

Phaeophyceae and rhodophyceae macroalgae from the Antarctic: A source of selenium

This study reports the development of a voltammetric method applied for Se determination in Phaeophyceae (A. utricularis, C. jacquinotii, A. mirabilis, D. anceps, H. grandifolius) and Rhodophyceae (G. confluens, C. racovitzae, I. cordata) macroalgae from the Antarctic. Evaluation of the instrumental parameters showed the square wave cathodic stripping voltammetry provided greater sensitivity (deposition potential, -0.4 V; deposition time, 420 s; amplitude, 0.08 V; frequency, 60 Hz) than influence of differential pulse cathodic stripping voltammetry. The matrix effect and the influence of Cu concentration on the determinations were also assessed. After microwave-assisted digestion of the samples, the quantification limit was from 5.21 × 10⁻³ (G.confluens) to 9.85 × 10⁻³ mg kg^-1 (I. cordata). The quantification of Se was carried out over the concentration range from 0.23 (C. jacquinotii) to 1.22 mg kg^-1 (A. mirabilis). The method accuracy was by analysing the reference material of peach leaves (SRM 1547).     

Major and trace elements levels in multifloral and unifloral honeys in Croatia

Different honey types were collected in Croatia during 2010 and 2011: 7 multifloral orchard honeys, 7 multifloral meadow honeys, 19 black locust, 9 chestnut, 11 lime and 6 sage honeys. Elements were measured using graphite (As, Cu, Cd, Pb, Se) and flame atomic absorption spectrometer (Ca, Fe, K, Mg, Na, Zn) and by mercury analyser (Hg). Significant differences in Ca, Fe, K, Mg, Zn, As and Hg levels were observed between honey types. In chestnut honey were determined (K, Ca, Mg: mg kg⁻¹; Hg, Ad, Cd: μg kg⁻¹): the highest concentrations of K 2824.4, Ca 486.7, Mg 59.1 and Hg 2.52; the lowest of As 24.1 and Cd 2.52. Lime honey has been shown the highest content of Cu (20.6 mg kg⁻¹), Zn (6.78 mg kg⁻¹), Cd (2.14 μg kg⁻¹) and Pb (810.3 μg kg⁻¹). The lowest levels of following elements were determined in black locust honey (Fe, K, Mg: mg kg⁻¹; Hg: μg kg⁻¹): Fe 2.77, K 304.7, Mg 8.02 and Hg 0.82. Sage honey had the lowest Ca and Na content (173.9 and 31.8 mg kg⁻¹). Among the multifloral honeys, the following was determined (Fe, Na, Cu: mg kg⁻¹; As, Pb: μg kg⁻¹): orchard honey – highest of Fe 5.17 and As 276.1, lowest Pb 301; meadow honey – highest Na 36.1, lowest Cu 4.38. The average Ca, Cu and Pb levels found in multifloral honey types were much higher than those reported in other European countries. Calcium levels in lime, chestnut and black locust were higher than those from other countries.     

Assessment of hydroxymethylfurfural and furfural in commercial bakery products

A survey was conducted on the presence of hydroxymethylfurfural (HMF) and furfural in bread and bakery products; for this purpose a reliable extraction procedure followed by high performance liquid chromatography (HPLC) was applied. The performance of the method was evaluated in terms of linearity (r always > 0.99); detection limits (0.001 mg L⁻¹ for furfural and 0.006 mg L⁻¹ for HMF); recovery percentages (98.5–100.5% for HMF and 94.9–98.9% for furfural); intraday precision (<4.65%) and interday precision (<7.51%). Two batches of a wide variety of products commercially available were analysed (a total of 88 samples). HMF and furfural levels presented high variability between products and batches of the same product. Cake/pastry samples showed the lowest HMF content (3.0 mg kg⁻¹ fw) while biscuits showed the highest content (7.8 mg kg⁻¹ fw) (p < 0.05). Regarding furfural, bread samples presented the highest furfural content (5.3 mg kg⁻¹ fw) (p < 0.05), cake/pastry and biscuits showed the lowest content (1.9 and 3.0 mg kg⁻¹ fw, respectively). Chocolate containing samples presented higher amounts of furfural (>20 mg kg⁻¹). These results indicate that special attention should be given to furfural content of bread (due to its daily high consumption) and re-evaluation of dietary exposure.