Petru Jitaru

This study reports primarily the levels of potentially toxic trace elements (PTTEs) in herring side-streams (skin, head, backbone, belly flap, viscera, and their mixture) and oils as raw materials for new ingredients and foods. Levels of 25 elements were determined by inductively coupled plasma-mass spectrometry after acidic digestion. Samples with Hg and As levels >limit of quantification (LQ) were analyzed by high-performance liquid chromatography (HPLC) coupled to ICP-MS to quantify inorganic and methylmercury species and the inorganic As (iAs) fraction. The levels of Pb and Hg in all side-streams were <EU-regulated limits for edible muscle, while the level of Cd was above the regulated limit in all side-streams except for the skin. All PTTE levels were <limit of detection (LD) in oil except for As; however, the iAs level was <0.1%. This work offers valuable insights regarding the risks and benefits of herring side-streams and ingredients.

This study presents the development and validation of a precise analytical method for the speciation analysis of arsenic (As) compounds, including inorganic species [As(III) and As(V)] and organic species such as monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). The method employs anion-exchange high-performance liquid chromatography (AE HPLC) coupled with inductively coupled plasma–mass spectrometry (ICP-MS). To optimize the sample preparation process, microwave-assisted extraction (MAE) and heat-assisted extraction (HAE) techniques were evaluated and compared. Separation of all four arsenic species was achieved with baseline resolution within 10 min, utilizing an anion-exchange column and a mobile phase gradient of 0.5 and 5 mM ammonium carbonate with 3% (v/v) methanol at a pH of 9.3. The method validation followed the accuracy profile approach, employing six different food matrices analyzed in duplicate over six separate days within a 6-week period. The method demonstrated good intermediate reproducibility, with coefficients of variation (CV_R) ranging from 4.7% to 5.5%, while the bias was < 3%. The limit of quantification (LOQ) for the four species was 6.25 μg/kg (dry weight, dw), and the limit of detection (LOD) was 1.88 µg/kg (dw). These results confirm the robustness, accuracy, and suitability of the method for routine As speciation analysis across a variety of food matrices. The method is specifically intended to be applied to the analysis of a panel of food samples as part of the ongoing (French) third total diet study.

Edible insects are becoming increasingly popular as protein alternatives to traditional animal-based products. As such, information on their elemental composition is important to ensure they are safe for human consumption. This article describes the development and validation of a rapid, reliable method for the simultaneous determination of 19 elements (Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Pb, Se, Sr, and Zn) in edible insects by inductively coupled plasma mass spectrometry (ICP-MS) following closed vessel microwave digestion. The method was validated using three insect certified reference materials, namely black soldier fly larvae meal (BFLY-1), cricket flour (KRIK-1), and mealworm powder (VORM-1). The method was applied to analyze twelve different (whole) insect species. The maximum amount of each sample was calculated for As, Cd, and Pb with respect to their provisional tolerable daily intake values established by the Food and Agricultural Organization/World Health Organization. Most of the samples, except for scorpions and tarantulas, were safe to consume at large doses (1000–10,000 insects per day). Furthermore, most of the samples contained high levels of Fe, K, Na, and Zn, providing a preliminary overview of the nutritional profile of these novel protein alternatives.

This study addresses the development and validation of an analytical method for speciation analysis of mercury (inorganic/Hg²⁺ and methylmercury/CH₃Hg⁺) in fishery products. The Hg species are separated by reversed-phase (RP) high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The effective separation of Hg²⁺ and CH₃Hg⁺ was achieved in 3Hg⁺ and 1.2 µg/kg (ww) for Hg²⁺. The intermediate reproducibility in terms of coefficient of variation (CV_R) was 3Hg⁺ and Hg²⁺ in fishery products. The method is intended to be applied for the analysis of the panel of fishery products and fish-based foods in the framework of the (ongoing) third French Total Diet Study.

This study addressed primarily the characterisation and quantification of titanium dioxide (TiO₂) (nano)particles (NPs) in a large variety of commercial foodstuffs. The samples were purchased from local markets in Spain before the ban of TiO₂ food additive (E171) in the EU. The analyses were carried out by single particle inductively coupled plasma-tandem mass spectrometry (spICP-MS/MS) in mass shift mode (oxidation of ⁴⁸Ti to ⁴⁸Ti¹⁶O (m/z = 64)) and using a highly efficient sample introduction system (APEX™ Ω). This novel analytical approach allowed accurate characterisation of a large panel of TiO₂ NPs sizes ranging from ∼12 to ∼800 nm without isobaric interferences from ⁴⁸Ca isotope, which is highly abundant in most of the analysed foodstuffs. TiO₂ NPs were extracted from foodstuffs using sodium dodecyl sulphate (0.1%, w/v) and diluted with ultra-pure water to reach ∼ 1000 particles signals per acquisition. All the analysed samples contained TiO₂ NPs with concentrations ranging from 10¹⁰ to 10¹⁴ particles kg^-1, but with significant low recoveries compared to the total Ti determination. A selection of samples was also analysed using a similar spICP-MS/MS approach with a conventional sample introduction system. The comparison of results highlighted the improvement of the limit of detection in size (12 nm) by the APEX™ Ω system, providing nanoparticulate fractions ranging from ∼4% (cheddar sauce) up to ∼87% (chewing gum), which is among the highest nanoparticulate fractions reported in literature using a spICP-MS approach. In addition, two commercially available E171 additives were analysed using the previous approaches and other techniques in different European laboratories with the aim of methods inter-comparison. This study provides occurrence data related to TiO₂ NPs in common commercial foodstuffs but it also demonstrates the potential of the novel analytical approach based on APEX™-ICP-MS/MS to characterise nano-size TiO₂ particles in complex matrices such as foodstuffs.

This study addresses the effect of various cooking approaches on total Hg (Hg_T) and total Se (Se_T) contents in three predatory fish species. For this purpose, samples of swordfish, dogfish, and tuna from regular French (fish) markets were cooked by boiling, steaming, grilling, and frying, respectively. The levels of Hg_T and Se_T in raw and cooked samples were determined by inductively coupled plasma-mass spectrometry. The data showed a significant increase in Hg_T and Se_T levels between raw and cooked samples (33% of the samples for Se_T and 67% for Hg_T) due to the water loss during the cooking. High intra-species variation related to Hg_T and Se_T levels was found. Considering the level of exposure to Hg_T through fish consumption and taking also into account the possible protective effect of Se (expressed here via the Se/Hg molar ratio), the safest cooking approach corresponds to grilled swordfish, fried tuna, and steamed dogfish, which show Se/Hg molar ratios of (1.0 ± 0.5), (4.3 ± 4.2), and (1.0 ± 0.6), respectively.

This study reports a novel analytical approach for the simultaneous determination of ethylene-thiourea (ETU) and propylene-thiourea (PTU) in fruits and vegetables by (reverse phase) high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma-tandem mass spectrometry (ICP-QQQMS or ICP-MS/MS). A baseline separation of ETU and PTU was achieved in less than 5 min. A robust method validation by using the accuracy profile approach was performed by carrying out four measurement series in duplicate at six different levels over a timespan of 4 weeks (different days). The recovery factors ranged from 87 to 101% for ETU and from 98 to 99% for PTU (depending on the spiking level). The coefficient of variation in terms of repeatability (CV_r) ranged from 1 to 4.7% for ETU and from 1.8 to 3.9% for PTU (depending also on the analyte level) while the coefficient of variation in terms of intermediate reproducibility (CV_R) ranged from 3.4 to 10% for ETU and from 1.8 to 10.8% for PTU. The limit of quantification was 0.022 mg kg⁻¹ (wet weight) for ETU and 0.010 mg kg⁻¹ (ww) for PTU. This novel approach was proved to be highly robust and suitable for the determination of ETU and PTU in foodstuffs of vegetal origin. Graphical Abstract

This study reports the development and validation of a new analytical method for simultaneous speciation analysis of Se and Hg in fish muscle. For this purpose, four Se species (selenite/Se(IV), selenate/Se(VI), selenomethionine/SeMet, and selenocysteine/SeCys) and two Hg species (inorganic mercury/iHg and methylmercury/MeHg) were extracted simultaneously by microwave-assisted enzymatic hydrolysis and then separated by HPLC in less than 15 min by using a column with both anion and cation exchange mechanisms and a mobile phase consisting of a mixture of methanol 5% (v/v), 45 mM HNO₃, 0.015% 2-mercaptoethanol, and 1.5 mM sodium 3-mercapto-1-propanesulfonate. The separated species of Hg and Se were detected online by inductively coupled plasma-mass spectrometry (ICP-MS). The speciation analysis method was validated by means of the accuracy profile approach by carrying out three series of measurements in duplicate on three different days over a time-span of 3 weeks. The limits of quantification (LOQ) are in the range of 0.010–0.013 mg/kg wet weight (ww) for all selenium species, except for Se(IV) (0.15 mg/kg ww), while the coefficient of variation in terms of intermediate reproducibility (CV_R) was < 7%. The LOQ for MeHg was 0.006 mg/kg ww, while the CV_R was 3%. The method was successfully applied to the analysis of muscle samples from four different fish species: rainbow trout, tuna, swordfish, and dogfish. Graphical Abstract

This study aimed at the assessment of the impact of various culinary processes on the fate of chromium (Cr) species (Cr(III) and Cr(VI)) in infant formula milk, semi-skimmed milk and bovine meat samples. The cooking procedures were boiling at 70°C/100°C (milk samples) and frying without and with oil (95°C and 120°C) (bovine meat). The levels of Cr(III) and Cr(VI) in raw and cooked samples were determined by high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICP-MS) using double spike species-specific-isotope dilution (SS-ID). The species were extracted by sequential complexation of Cr(III) with ethylenediaminetetraacetic acid and of Cr(VI) with 1,5-diphenylcarbazide in the same analytical run by heating at 70°C for 50 min. Anion exchange chromatography using a Dionex IonPac™ AG7 column and a mobile phase consisting of 10 mM HNO₃, 2.5% MeOH and 30 mM EDTA at pH 2 was employed for species separation. The quantification limits were 0.013 and 0.049 µg kg⁻¹ for Cr(III) and Cr(VI), respectively. ANOVA test used to compare the mean Cr species concentrations showed no significant differences between raw and cooked samples. The results obtained in the present study show that oxidation of Cr(III) to Cr(VI) does not occur during thermal cooking of milk and bovine meat samples. A selection of 10 samples of each type were analysed in terms of total Cr (Cr_total) as well as speciation (Cr(III) and Cr(VI)). Cr(VI) was not quantified in any of these samples, whereas Cr(III) levels ranged from 0.22 (infant formula milk) up to 80 µg kg⁻¹ (chorizo sausage). Additionally, Cr(III) and Cr_total levels were comparable hence demonstrating that in the samples analysed in this study, Cr is found exclusively as Cr(III) species. Graphical Abstract