Elements In Food Products Research Articles

Spectroscopic assessment and quantitative analysis of the trace element composition of vegetable additives to meat products

In this scientific work, using the method of laser-induced breakdown spectroscopy (LIBS), the spectra of beef samples and impurities in meat products, namely, banana, pineapple, kiwi, bergamot, poria coconut, Chinese angelica, chicken blood vine, were measured by using developed experimental devices. The purpose of the research was to evaluate the qualitative characteristics of additives to meat semi-finished products for the potential formation of the desired properties of the products due to the analysis of the received spectrograms of trace elements of the samples when applying the LIBS method, quantitative analysis for processing the received information. The determined values of the electron temperature of the plasma, the electron density of the used raw material samples, and the assessment of the local heat balance were used as evaluation criteria. When processing the obtained data, the characteristics of the laser-induced plasma surface of the presented samples were analyzed; the electron temperature and electron density were determined, and a quantitative analysis of trace elements was carried out. LIBS technology allows rapid real-time monitoring and qualitative analysis of trace elements online and over long distances. During the research, it turned out that quantitative analysis requires further study and optimisation of experimental conditions, such as pre-treatment of samples. These conditions optimise defocusing, double laser pulse, and sample temperature, which increases the signal/noise ratio of all spectral lines. The combination of fluorescence spectroscopy and Raman technology enables higher detection sensitivity and better molecule control, creating a quantitative analysis method model that can reduce matrix effects and overcome the self-absorption effect. Among the difficulties of using LIBS technology, several elements can be noted online simultaneously, compared to Raman. The combination of spectroscopy and fluorescence spectroscopy can obtain more comprehensive information about the composition of materials, which can become a potential platform for monitoring trace elements in food products.

Discrimination of geographical origin of Korean and Chinese red pepper paste via inductively coupled plasma atomic emission spectroscopy and mass spectrometry

BackgroundRed pepper paste is a common ingredient used in food in Korea. The discrimination of the geographical origin of agricultural products is important to protect the agricultural industry and customers from the misinformation regarding the product origin. Several studies have attempted to identify the geographical origin of red pepper based on its characteristic features using diverse methods, such as inorganic elemental analysis. However, similar studies on red pepper pastes have not been conducted thus far.ResultsIn, this study, we established methods based on inductively coupled plasma optical emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) for determining inorganic elements in red pepper pastes. The limit of detection (LOD) of ICP-AES was in the range of 0.006–0.531 mg∙kg−1 and the limit of quantification (LOQ) was 0.017–1.593 mg∙kg−1. In addition, LOD and LOQ ranges for ICP-MS were 0.001–1.553, and 0.002–5.176 μg∙kg−1, respectively. The concentrations of Ca, K, Mg, Na, P, S, Cr, Mn, Co, Ni, Cu, Ga, As, Sr, Zr, Mo, Pd, Cd, Sn, Sb, Ce, Pt, Pb, and U were high in the Korean red pepper paste. All the employed discrimination models could clearly distinguish between Korean and Chinese red pepper pastes. In particular, among the four different models, CDA showed the most accurate ability to discriminate the geological origin of Korean and Chinese red pepper paste compared to that achieved using the other models with 100% accuracy.ConclusionsBased on, the findings of this study, the use of ICP-AES and ICP-MS analyses for discriminating the inorganic elements in food products in combination with the aforementioned statistical analysis models could help the mitigation of issues associated with the misinformation of the geographical origin of agricultural products, aiding customer protection.Graphical

Prospects for the use of layer-by-layer technology for the development of an enzyme biosensor used for milk quality control

This article presents the results of scientific research on the development of a biosensor system for the determination of salts of heavy metals (cadmium and lead) in milk. When developing a biosensor system, much attention is paid to the selection of biological material and the method of their stabilization using physical and chemical forces, namely, immobilization. In this regard, studies were carried out on the selection of the enzyme and the method of its immobilization in the development of a biosensor for the detection of salts of heavy metals in milk. The development of a biosensor for the determination of toxic elements in food products is of scientific and practical importance. In world practice, special attention is paid to the contamination of raw materials and food products with toxic chemicals, mainly of anthropogenic origin, which are persistent organic pollutants. Therefore, quality control of raw materials, food products is important for consumers, and, accordingly, for the food industry. Experimental studies are based on the methods of Filippova A. M., Vorobieva O. V. to determine the specific activity of the enzyme acetylcholinesterase. Determination of the activity of the catalase enzyme was carried out in accordance with the gasometric method according to the method of Warburg. As a result of experimental studies, the catalase enzyme as a biological material was chosen as a sensitive element. As a carrier for the immobilization of enzymes, a 5-bilayer combination of "chitosan-sodium alginate" was selected. The layer-by-layer technology was used to immobilize the enzyme on the substrate surface when creating an enzyme biosensor. The results of the research are recommended to be applied in the study of food safety issues and in the assessment of safety indicators of raw materials and food products by the express method.

Гигиенические аспекты безопасности пищевых продуктов для питания детей первого года жизни

Objective. To conduct a hygienic assessment of chemical contamination of food products for infant nutrition. Materials and methods. Analysis of databases on the content of toxic elements (lead, cadmium, mercury, arsenic) in food products for infant nutrition and the infant morbidity rate according to the materials of social and hygienic monitoring in the Russian Federation was performed. The structure of nutrition for infants was studied. Based on the results of generated databases, the hazard quotient was calculated at the level of the median content of toxic elements in food products. Results. The primary chemical pollutants in food products for infants were found to be toxic elements (61.4% of samples), of which lead prevails. When analyzing the infant morbidity rate, an increase in gastrointestinal pathologies (by 15.7%) was observed, and in several cases – anemia and endocrine system diseases. It was revealed that only 37.3% of infants receive breastfeeding, and there is a violation of the timing of complementary food introduction (25.3%). Analysis of non-carcinogenic health risks showed that for formula-fed infants, the risk of alimentary-dependent diseases increases with age by months, which was confirmed by calculations of the hazard quotient (HQmedPb = 1.1; HQmedCd = 1.37; HQmedAs = 1.39). Conclusion. To prevent the morbidity rate in infants due to chemical contamination of food products, it is necessary to support breastfeeding, strict compliance with the terms of introduction and volume of complementary foods, and training in health education for medical students in accordance with the requirements of professional standards. Key words: infants, food products, toxic elements

Analysis of the results of control of toxic elements in food

The article discusses the experimental substantiation of the use of the stripping voltammetry method in order to organize and control the process of measuring toxic elements in food products, the quantitative criteria of which are direct indicators of safety. Comparative results are given □□ the example of dairy and milk-containing products and criteria for the amount of toxic elements in products and their norms, in particular. The analysis of the monitoring points related to the work logs for the control of these elements was carried out, the processes of the quantitative chemical analysis of the collected samples were studied. The sample data was tracked by the specified method of IV measurements on a «TA-1» voltammetric analyzer. Also, the analysis of regulatory and various technical documentation for the level of pollution by toxic elements of our environment was carried out and the possibilities of ways of excretion and their entry into products were considered. Intralaboratory control instruments were used in the form of control charts; according to the results of the construction of which, the results of correctness and accuracy were determined and interpreted. Managing these safety processes is one of the stable analysis of evaluating the internal control of the parameters of results and obtaining close-reliable conclusions. As a result of the research, indicators of the correctness and accuracy of the data were derived.

Modern Methodological Approaches to Sample Preparation for the Determination of Trace Elements in Food Products and Plant Raw Materials

Introduction. Various copper compounds are most widely used as plant protection agents in agriculture. From a hygienic point of view, information on excessive accumulation of copper in plants related to the use of a specific formulation of copper-containing pesticides is of interest. Our objective was to assess feasibility of increasing statistical significance of results of determining low residue levels of a copper-containing pesticide in apple samples by flame atomic absorption spectrometry using a high-resolution spectrometer in combination with developed approaches to sample preparation of plant-based foods, including homogenization with dry ice and microwave mineralization. Materials and methods: We analyzed 30 samples of apples collected in three different agro-climatic zones by flame atomic absorption spectrometry and electrothermal atomization atomic absorption spectrometry. Both methods were validated on 10 samples with added copper at levels 1-5 of the lower limit of quantitation. A statistical calculation was performed based on a simple Student’s test to assess the significance of differences between the results of measurements by flame and electrothermal techniques. Homogeneity of variances was estimated using the Fisher test to clarify the possibility of comparing two data sets. Results: The use of a technique of cryo-grinding and microwave decomposition in a microwave reactor in combination with a high-resolution continuum source atomic absorption spectrometry demonstrated a decrease in scattering and the limit of detection and better repeatability in the analysis of parallel samples. Results of statistical calculations confirmed the homogeneity of variances in data samples obtained for electrothermal and flame techniques, and the further Student’s t-test showed insignificant differences between the results of measurements obtained by FAAS and ET-AAS. Conclusion: Our findings prove that modern methods of sample preparation in combination with highly sensitive equipment allow a significant reduction in the limit of detection and scattering of test results.

Mitigation of potentially toxic elements in food products by probiotic bacteria: A comprehensive review

Potentially toxic elements (PTEs) as non-degradable elements (especially carcinogenic types for humans such as lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As)) are widely distributed in the environment. They are one of the most concerned pollutants that can be absorbed and accumulated in the human body, primarily via contaminated water and foods. Acute or chronic poisoning of humans to PTEs can pose some serious risks for human health even at low concentrations. In this context, some methods are introduced to eliminate or reduce their concentration. While the biological treatment by bacterial strains, particularly probiotic bacteria, is considered as an effective method for reducing or eliminating of them. The consumption of probiotics as nonpathogenic microorganisms at regular and adequate dose offer some beneficial health impacts, it can also be applied to remove PTEs in both alive and non-alive states. This review aimed to provide an overview regarding the efficacy of different types of probiotic bacteria for PTEs removal from various environments such as food, water, in vitro, and in vivo conditions.

Analysis of gmo contents as a component in risk-oriented surveillance over food products safety

Control over use of genetically modified products is a vital task within a risk-oriented model for surveillance over food safety products all over the world including the Russian Federation. Our research goal was to examine domestically manufactured food products in order to determine whether they contained certain regulatory sequences typical for genetically modified organisms. We applied polymerase chain reaction with hybridization-fluorescent detection in real time mode to examine 77 food products samples; the task was to determine whether they contained DNA enhancer (E-35S) and promoter (P-35S) of S35 sequence belonging to cauliflower mosaic virus, terminator of nopaline synthase gene from Agrobacterium tumefaciens (T-NOS), 35S enhancer (E-FMV) and promoter (P-FMV) of Figwort mosaic virus, as well as vegetable DNA inducing soya DNA. When analyzing the extracted DNA, we didn’t detect transgenic elements in any samples; however, there were vegetable components reveled in them including 68.8% samples with soya DNA. We established that some sausages were falsified as they contained vegetable elements. In 15.6% cases data on a product structure turned out to be false because soya DNA was not listed on consumer package. Our research on determining soya DNA and transgenic elements in food products indicates that soya ingredients have been added into food products in spite of their absence in relevant documents as recipe components. All the obtained results taken into account, we assume it is necessary to improve control procedures for detecting genetically modified and vegetable components used as ingredients in food products as their falsification can make for changes not only in their consumer properties but also damage consumers’ health.

Анализ содержания компонентов генетически модифицированных организмов как элемент риск-ориентированного надзора за безопасностью пищевых продуктов

Control over use of genetically modified products is a vital task within a risk-oriented model for surveillance over food safety products all over the world including the Russian Federation. Our research goal was to examine domestically manufactured food products in order to determine whether they contained certain regulatory sequences typical for genetically modified organisms. We applied polymerase chain reaction with hybridization-fluorescent detection in real time mode to examine 77 food products samples; the task was to determine whether they contained DNA enhancer (E-35S) and promoter (P-35S) of S35 sequence belonging to cauliflower mosaic virus, terminator of nopaline synthase gene from Agrobacterium tumefaciens (T-NOS), 35S enhancer (E-FMV) and promoter (P-FMV) of Figwort mosaic virus, as well as vegetable DNA inducing soya DNA. When analyzing the extracted DNA, we didn’t detect transgenic elements in any samples; however, there were vegetable components reveled in them including 68.8% samples with soya DNA. We established that some sausages were falsified as they contained vegetable elements. In 15.6% cases data on a product structure turned out to be false because soya DNA was not listed on consumer package. Our research on determining soya DNA and transgenic elements in food products indicates that soya ingredients have been added into food products in spite of their absence in relevant documents as recipe components. All the obtained results taken into account, we assume it is necessary to improve control procedures for detecting genetically modified and vegetable components used as ingredients in food products as their falsification can make for changes not only in their consumer properties but also damage consumers’ health.

Heavy metal levels in milk and fermented milk products produced in the Almaty region, Kazakhstan.

Background and Aim:Monitoring food quality and safety remain a pressing issue. The intermediate results of the study on the residual amounts of heavy and toxic elements in food products are presented herein. The aim of this study was the determination of heavy metals in milk and fermented milk products from basic farms in the Almaty region, Kazakhstan.Materials and Methods:A total of 120 raw milk samples and 80 cottage cheese samples were analyzed. The milk and cottage cheese samples were subjected to mineralization during the analysis to remove organic impurities and determine the heavy metal concentrations using atomic absorption spectrometry.Results:The contents of cadmium, lead, and arsenic in all raw materials and food products did not exceed the maximum permissible concentrations.Conclusion:The dairy samples showed low contents of cadmium, mercury, lead, and arsenic that did not exceed the allowable concentrations for basic farms in the Almaty region.

Determining the microelement composition of poppy seeds using solid­phase spectrophotometry method

Poppy seeds are one of the most important and oldest oil-bearing crops in the world. Therefore, quality control of poppy seeds and food products whose composition contains them as a food additive, is very important. To this end, we have applied procedures for solid-phase spectrophotometric and photometric determining of micro elements in food products. It was established that in determining cadmium and zinc, the best ion exchanger for the group concentration of interfering metal ions is the ion exchanger with the immobilized KO. made it possible to concentrate and determine in the solid phase the ions of Hg(II). Using enabled selective determining of Pb(II). Selective determining of the Fe(III) ions at pH 3 was conducted using ammonium thiocyanate. Cu(II) was determined photometrically upon masking the ions of Fe(III) employing SPADNS. Based on the data acquired, we have developed a microelement analysis scheme for poppy seeds. It was established that the sample contained, mg/kg: Cu(ІІ) – 5.0; Pb(ІІ) – 0.3, Zn(ІІ) – 50, P(V) – 1,600, K − 550, Na – 20, Ca – 1,500, Mg(II) – 450; Fe(ІІІ) −10; Cd(ІІ) and Hg(ІІ) are absent. The proposed scheme for analysis of poppy seeds is universal and could be applied for microelement analysis of other food products. The procedures employed are characterized by sensitivity and selectivity. Ion exchangers with the immobilized dyes, as well as procedures for the solid-phase spectrophotometric determining, are environmentally safe. They do not require the use of toxic organic reagents. The procedures applied are easy to use. Relative standard deviation in the results does not exceed 0.10. This indicates good reproducibility of the results.

Multi-elemental analysis of Lentinula edodes mushrooms available in trade

ABSTRACTThe present study investigated the content of 62 elements in the fruiting bodies of Lentinula edodes (Shiitake mushroom) cultivated commercially in Poland on various substrates from 2007–2015. The general mean content (mg kg−1 dry weight (DW)) of the studied elements ranked in the following order: K (26,335) > P (11,015) > Mg (2,284) > Ca (607) > Na (131) > Zn (112) > Fe (69) > Mn (33) > B (32) > Rb (17) > Cu (14.5) > Al (11.2) > Te (2.9) > As (1.80) > Cd (1.76) > Ag (1.73) > Nd (1.70) > Sr (1.46) > Se (1.41) > U (1.11) > Pt (0.90) > Ce (0.80) > Ba (0.61) > Co (0.59) > Tl (0.58) > Er (0.50) > Pb (0.42) > Li (0.40) > Pr (0.39) > Ir (0.37) > In (0.35) > Mo (0.31) > Cr (0.29) > Ni (0.28) > Sb (0.26) > Re (0.24) > Ti (0.19) > Bi (0.18) > Th (0.12) > La (0.10) = Pd (0.10) > Os (0.09) = Zr (0.09) > Rh (0.08) > Ho (0.07) > Ru (0.06) > Sm (0.04) = Eu (0.04) = Tm (0.04) > Gd (0.03) > Sc (0.02) = Y (0.02) > Lu (0.01) = Yb (0.01) = V (0.01). The contents of Au, Be, Dy, Ga, Ge, Hf, and Tb were below the limits of detection (0.02, 0.02, 0.01, 0.01, 0.01, 0.01, 0.02 mg kg−1 respectively). The concentrations of Al, As, B, Ba, Ca, Cd, Cr, Er, Fe, In, Lu, Mn, Nd, Sr, Ti, Tm, and Zr were comparable over the period the mushrooms were cultivated. The study revealed that Lentinula edodes contained As and Cd at levels potentially adverse to human health. This highlights the need to monitor these elements in food products obtained from this mushroom species and ensure that only low levels of these elements are present in cultivation substrates.

Simultaneous Measurement of Zinc, Copper, Lead and Cadmium in Baby Weaning Food and Powder Milk by DPASV.

Apart from the breast milk, infant formula and baby weaning food have a special role in infant diet. Infants and young children are very susceptible to amount of trace elements. Copper and zinc are two elements that add in infant food. Lead and cadmium are heavy metals that enter to food chain unavoidably. DPASV is a benefit and applicable method for measurement of trace elements in food products. In this study, concentration of zinc, copper, lead and cadmium in four brands of baby food (rice and wheat based) and powder milk was analyzed with DPASV and polarograph set. Total Mean ± SE of zinc, copper, lead and cadmium in baby foods (n = 240) were 11.86 ± 1.474 mg/100g, 508.197 ± 83.154 μg/100g, 0.445 ± 0.006, 0.050 ± 0.005 mg/Kg respectively. Also these amount in powder milk (n = 240) were 3.621± 0.529 mg/100g, 403.822 ± 133.953 μg/100g, 0.007 ± 0.003, 0.060 ± 0.040 mg/Kg respectively. Zinc level in baby food type I was higher than lablled value (P = 0.030), but in other brands was not difference. Concentration of copper in all of samples was in labeled range (P > 0.05). In each four products, level of lead and cadmium were lower than the standard limit (P < 0.05). Amount of zinc and lead in baby food I, had difference versus other products. Concentration of zinc, camium in baby food type I, was higher than type II (P = 0.043, 0.001 respectively). Concentration of lead and cadmium in baby food type II, was higher than infant formulas, but are in standard limit.

Trace element speciation in food: State of the art of analytical techniques and methods

Some elements in food are notoriously toxic, whereas others are considered essential for human health. Information on the exact chemical form in which an element is present in food is of paramount importance to determine the safety and nutritional quality of food. This critical review discusses the state of the art of analytical approaches to speciation of trace elements in food products. The topics addressed include (i) responding to regulations concerning some toxic elements (As, Hg, Sn); (ii) quality control of food and feed supplements; and (iii) characterization, in terms of element speciation, of nutritional plants (natural and genetically modified) and food supplements produced by biotechnology. The maturity of analytical techniques allowing the determination of individual well-defined metal species is highlighted. On the other hand, the recent developments of multidimensional hyphenated techniques and the democratization of electrospray high-resolution mass spectrometry (Orbitrap) start permitting fine characterization of element speciation in natural products.

Determination of Calcium, Copper, Iron, Magnesium, Manganese, Potassium, Phosphorus, Sodium, and Zinc in Fortified Food Products by Microwave Digestion and Inductively Coupled Plasma-Optical Emission Spectrometry: Single-Laboratory Validation and Ring Trial

A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-optical emission spectrometry in order to modernize AOAC Official Method 984.27. The improvements involved extension of the scope to all food matrixes (including infant formula), optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed- or open-vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proven through a successful RT using experienced independent food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD, and HorRat values) regarding SLVs and RTs. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an extended updated version of AOAC Official Method 984.27 for fortified food products, including infant formula.

Determination of 137Cs, 90Sr, 40K radionuclides in food grain and commercial food grain products

Following up transfer of strontium from soil to plants requires determination of isotope in the surface layer of soil and a chosen plant. The most endangered food products are plants including commonly grown grain, which constitutes a basic feeding component for both people and animals. Indeed large amounts of 137 Cs, 90 Sr get into organisms of people and animals with the food, therefore determination of radioactivity of elements in food products and animal fodder is very essential. Choice of proper diet allows to limit the level of human organism denaturation. The aim of this paper was to study relocation of 90 Sr, 137 Cs, 40 K isotopes from soil to grain and then from grain to food products. There were investigated soil, wheat, barley, groats, flour, macaroni and breakfast flakes. Based on the obtained results there were calculated effective weighted doses (nSv) from consumption of 1 kg of a product for different age groups.

Improvement of AOAC Official Method 984.27 for the Determination of Nine Nutritional Elements in Food Products by Inductively Coupled Plasma-Atomic Emission Spectroscopy After Microwave Digestion: Single-Laboratory Validation and Ring Trial

A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-atomic emission spectroscopy in order to improve and update AOAC Official Method 984.27. The improvements involved optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed or open vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proved through a successful internal RT using experienced food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD and HorRat values) regarding SLV and RT. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an improved version of AOAC Official Method 984.27 for fortified food products, including infant formula.

Methods of Analysis for Toxic Elements in Food Products. 2. Review of USSR Standards on Determinations of Heavy Metals and Arsenic

Methods of analysis prescribed by USSR standards for Hg, Pb, Zn, As, Cd, Cu, Fe, and Sn in foods are described: for Hg--colorimetry of tetraiodide mercurate and atomic absorption spectroscopy (AAS); for Pb, Cd, Zn, and Cu--polarography; for Cu--colorimetry with sodium diethyldithiocarbamate and zinc dibenzyldithiocarbamate; for As--colorimetry with silver diethyldithiocarbamate; for Sn--colorimetry with quercetin; and for Fe--colorimetry with o-phenanthroline. All of the methods have the necessary metrological characteristics, including intralaboratory repeatability value (r), interlaboratory reproducibility value (R), minimum quantity of the element to be determined in the analytical test portion (MQSM), and the coefficients that account for mercury and arsenic losses during analysis. Establishing constant r- and R-values for the methods under consideration is expedient because (a) the methods suggested are used for safety purposes; and (b) the optimum amount of the element studied in the test sample is determined, to a certain degree, by the mass of the test portion.

Methods of Analysis for Toxic Elements in Food Products. 1. Mineralization Methods to Determine Heavy Metals and Arsenic According to the USSR Standard

Results of the work of 22 laboratories in the USSR on optimizing methods for mineralizing foods to determine Pb, Cd, As, Zn, Cu, Sn, and Fe are summarized. Recommendations are given on dry and wet mineralization as related to the analyte and the kind of food product. Optimum amounts of test portions for 22 food groups are also recommended according to the element of interest.

Methods of Analysis for Toxic Elements in Food Products. 3. Limit of Determination of Methods for Assuring Safety

To evaluate the suitability of the analytical methods used in determining food safety, a new metrological characteristic "MQS" is suggested. MQS is defined as the absolute minimum quantity in micrograms of a substance that can be determined in a test solution (solubilized test portion). MQS accounts for 2 factors: (a) the necessity for a reliable determination of ML (maximum permitted level, i.e., regulatory tolerance), and (b) the optimum quantity of test portion of a food product to be analyzed, and thus assists in evaluating the suitability of a method to assure food safety. The MQS of 8 toxic elements in any food are As, 3; Cd, 0.5; Cu, 20; Fe, 50; Hg, 0.2; Pb, 4; Sn, 200; Zn, 100 micrograms. To characterize the applicability of any given method, the specific minimum limit of determination, MQSM, must be established for each method. The method in question may be used to control food safety only if MQSM is less than MQS. MQSM values are given for the common polarographic and colorimetric methods for determining these elements.