Optimization and validation of the kinetic spectrophotometric method for quantitative determination of the pesticide atrazine and its application in infant formulae and cereal-based baby food.

BACKGROUND: Pesticides are potentially toxic to humans and can produce both acute and chronic health effects, depending on the quantity and the ways in which a person is exposed. Exposure to pesticides can cause serious health problems. Infants and young children are particularly sensitive to these contaminants because their brains and organ systems are not fully developed. For this reason, it is important to determine the quantities of pesticides in baby food. RESULTS: The aim of this study was to develop a kinetic-spectrophotometric method for atrazine determination and to apply it to determine pesticide in baby-food samples, using solid-phase extraction (SPE) followed by the kinetic-spectrophotometric method and the high-performance liquid chromatography (HPLC) method. This method is based on the inhibition effect of atrazine (the oxidation of sulfanilic acid (SA) by hydrogen peroxide in the alkaline medium in the presence of the Co2+ ion). Under the experimental conditions used, atrazine showed a linear dynamic range of 0.5 to 5.0 µg mL-1 , and from 5.0 to 70.00 µg mL-1 with relative standard deviations (RSD) from 1.91% to 9.41%. The limit of detection and the limit of quantification were 0.074 and 0.225 µg mL-1 , respectively. The kinetic method was successfully applied to determine the atrazine concentration in spiked samples after SPE of samples. High-performance liquid chromatography was used to verify the results. CONCLUSION: The proposed method is highly sensitive, simple, easy, requires cheap reagents, and leads to good recovery levels. It is linear, precise, and accurate. It can be used successfully for the routine analysis of atrazine in infant formulae and cereal-based food samples. © 2019 Society of Chemical Industry.

Elemental composition of edible nuts: fast optimization and validation procedure of an ICP-OES method.

BACKGROUND: An inductively coupled plasma-optical emission spectrometry method for the speedy simultaneous detection of 19 elements in edible nuts (walnuts: Juglans nigra; almonds: Prunus dulcis; hazelnuts: Corylus avellana; Brazil nuts: Bertholletia excelsa; cashews: Anacardium occidentalle; pistachios: Pistacia vera; and peanuts: Arachis hypogaea) available on the Serbian markets, was optimized and validated through the selection of instrumental parameters and analytical lines free from spectral interference and with the lowest matrix effects. RESULTS: The analysed macro-elements were present in the following descending order: Na > Mg > Ca > K. Of all the trace elements, the tested samples showed the highest content of Fe. The micro-element Se was detected in all the samples of nuts. The toxic elements As, Cd and Pb were either not detected or the contents were below the limit of detection. One-way analysis of variance, Student's t-test, Tukey's HSD post hoc test and hierarchical agglomerative cluster analysis were applied in the statistical analysis of the results. CONCLUSION: Based on the detected content of analysed elements it can be concluded that nuts may be a good additional source of minerals as micronutrients.

Quantitative determination of selected elements in infant baby formulae and baby food cereals commercially available in Serbia using the ICP OES method.

The aim of this paper was the quantitative determination of some macro and trace elements, especially potentially toxic elements in the samples of infant baby formulae and baby food cereals commercially available in Serbia using the inductively coupled plasma optical emission spectrometry (ICP OES) method. Among the macro elements, K is the most abundant in all infant formulae samples, followed by Ca, P, Na and Mg. On the other hand, the analysis of food cereals showed that P is presents in the highest contents, followed by K, Ca, Na, and Mg. Potentially toxic elements As, Pb, Hg, and Cd were not detected in any sample of infant formulae, while Cd was detected and quantified in cereal foods. Also, the calculated values of Estimated Tolerable Weekly Intake (ETWI) as well as the Estimated Tolerable Monthly Intake (ETMI) were lower than recommended values for a tolerable weekly intake (TWI) and provisional tolerable monthly intake (PTMI).

A simple method for the ampicillin determination in pharmaceuticals and human urine.

The new kinetically-based spectrophotometric method for the determination of microquantities of ampicillin is proposed in the present paper. Ampicillin degradation in strong alkaline medium was applied for the method development. The reaction rate was monitored at 265 nm. A differential variation of the tangent method was used to process the kinetic data. The method is valid over the 3.49-55.84 µg/mL ampicillin concentration interval with relative standard deviation (RSD) range 7.79-3.20%. The calculated detection limit was determined at 2.58 µg/mL based on the 3.3S0 criterion. The interference effects of some metal ions, anions, amino acids and other molecules were investigated in order to assess the method selectivity. The method was successfully applied to determining the content of ampicillin in commercial pharmaceutical preparations and human urine. The obtained results were in good correlation with the HPLC method results. The newly developed method is simple, inexpensive and efficient for the analysis of a large number of samples at room temperature in a short time.

Trace element content in commercial complementary food formulated for infants and toddlers: Health risk assessment.

The study aimed to analyze trace elements content in baby purees and fruit juices and to evaluate the health risk of young children. The average daily dose, hazard quotient, hazard index and total diet hazard quotient were calculated to assess the potential health risk on per capita and consumers only groups of infants and toddlers. There was no significant health risk for studied groups regarding the intake of trace elements via purees and juices consumption. Health risk for lead was not estimated since the oral reference dose for this metal was not yet established and PTWI value was withdrawn. The average daily dose of lead for infants (0.32 - 0.46 µg/kg bw/day) and toddlers (2.01 - 2.29 µg/kg bw/day) were in accordance with the daily lead exposure intervals estimated by EFSA. Applying statistical analysis, the products were classified into three groups according to the content of trace elements.

The Evaluation of ICP OES for the Determination of Potentially Toxic Elements in Lipsticks: Health Risk Assessment.

This study aimed to optimize and validate the inductively coupled plasma optical emission spectrometric method (ICP OES) for the simultaneous determination of eleven potentially toxic elements (Al, Cd, Cr, Co, Cu, Ni, Pb, Fe, Sb, Mn, and Zn) in lipstick samples. The method was evaluated by applying the standard addition method. The recoveries for all elements in lipsticks were between 90% and 110%, except for Cd and Pb they were <90% and >110%, respectively. The health risk assessment was determined by calculating the average daily intake (ADD), hazard quotient (HQ), and hazard index (HI). The highest mean value for ADD was for Fe (4.8×10-1 mg kg-1 day-1), and the lowest was for Co (9.3×10-6 mg kg-1 day-1). There was no significant toxic health risk for any of the elements (HQ < 1), except for Fe (HQ < 3) which indicates a potential health risk. Based on PCA, all potentially toxic elements have been classified in the three groups. The first group includes Fe, the second includes Al, and all other elements belong to the third group. The cluster analysis of the elements provided the identical grouping that was obtained on the basis of PCA. Two separate clusters were obtained when cluster analysis was applied to the analyzed samples. The first cluster contained the only sample that was brown. The second cluster was divided into two sub-clusters. The first sub-cluster included the samples belonging to category I regarding the price, while the second sub-cluster included the samples belonging to category II and III regarding the price.