The boron content of selected foods and the estimation of its daily intake among free-living subjects

Biogeochemical cycling, tolerance mechanism and phytoremediation strategies of boron in plants: A critical review

Boron (B) is an inimitable plant micronutrient, predominantly distinguished by super-narrow range between its deficiency and toxicity concentrations, which depends upon boron speciation in the growth media and form of living organisms. Moreover, the significant variations in its mobility amid different species, and distinctive inter and intra-species responses to extreme concentrations. Therefore, it is necessary to screen the bioavailability, speciation, biogeochemical cycling and exposure pathways of boron in the environment. The genes involved in the tolerance mechanism of boron in different plants were discussed in the current review paper. The functions related to scarcity and excess of boron concentration are assessed. The diverse plants implicated in phytoremediation of boron contaminated sites that restrict boron accumulation in food crops and health risks associated with soils containing deficit or surplus boron concentration were appraised. Ultimately, a summary of numerous strategies involved in the recovery and repair of boron-contaminated soils have been reviewed.

Nutritional therapy can reduce the burden of depression management in low income countries: A review

Depression is a serious mental and mood disorder with global health and economic burden. This burden may be overwhelming in low income countries, although there are insufficient data. Most antidepressant formulations are predicated on the monoamine, neuroendocrine and neuro-inflammation hypotheses, with little or no cognizance to other neurochemicals altered in depression. A nutritional strategy with or without conventional antidepressants is recommended, as nutrition plays vital roles in the onset, severity and duration of depression, with poor nutrition contributing to its pathogenesis. This review discusses nutritional potentials of utilizing omega-3 fatty acids, proteins, vitamins, minerals and herbs or their phytochemicals in the management of depression with the aim of reducing depression burden. Literature search of empirical data in books and journals in data bases including but not limited to PubMed, Scopus, Science Direct, Web of Science and Google Scholar that might contain discussions of sampling were sought, their full text obtained, and searched for relevant content to determine eligibility. Omega-3 fatty and amino acids had significant positive anti-depression outcomes, while vitamins and minerals although essential, enhanced omega-3 fatty and amino acids activities. Some herbs either as whole extracts or their phytochemicals/metabolites had significant positive anti-depression efficacy. Nutrition through the application of necessary food classes or herbs as well as their phytochemicals, may go a long way to effectively manage depression. This therefore will provide inexpensive, natural, and non-invasive therapeutic means with reduced adverse effects that can also be applied alongside clinical management. This nutritional strategy should be given more attention in research, assessment and treatment for those with depression and other mental illness in low income countries, especially in Africa.

Drosophila melanogaster as a Model Organism to Study Lithium and Boron Bioactivity

The fruit fly Drosophila melanogaster has become a valuable model organism in nutritional science, which can be applied to elucidate the physiology and the biological function of nutrients, including trace elements. Importantly, the application of chemically defined diets enables the supply of trace elements for nutritional studies under highly standardized dietary conditions. Thus, the bioavailability and bioactivity of trace elements can be systematically monitored in D. melanogaster. Numerous studies have already revealed that central aspects of trace element homeostasis are evolutionary conserved among the fruit fly and mammalian species. While there is sufficient evidence of vital functions of boron (B) in plants, there is also evidence regarding its bioactivity in animals and humans. Lithium (Li) is well known for its role in the therapy of bipolar disorder. Furthermore, recent findings suggest beneficial effects of Li regarding neuroprotection as well as healthy ageing and longevity in D. melanogaster. However, no specific essential function in the animal kingdom has been found for either of the two elements so far. Here, we summarize the current knowledge of Li and B bioactivity in D. melanogaster in the context of health and disease prevention.

Boron Intake and decreased risk of mortality in kidney transplant recipients

Purpose

In a search for potentially modifiable factors to improve long-term outcome among kidney transplant recipients (KTR), we hypothesized that boron exposure is associated with improved long-term outcome in KTR.

Methods

We determined 24 h urinary boron excretion using inductively coupled plasma mass spectrometry as a measure of boron exposure in 693 stable KTR (57% male, mean age 53y), enrolled in the TransplantLines Food and Nutrition Biobank and Cohort Study. Dietary intake was assessed using validated food-frequency questionnaires.

Results

Linear regression analyses showed that dietary intake of fruit, wine and nuts were key determinants of boron excretion. In addition, boron excretion was negatively correlated with homocysteine and inflammatory parameters. In total, 73 (32%), 47 (20%) and 30 (13%) KTR died among the lowest, middle and highest tertiles of 24 h urinary boron excretion, respectively (P_log-rank < 0.001). Cox regression analyses showed that high boron excretion was strongly associated with lower risk of mortality, independent of age, sex, estimated glomerular filtration rate and history of cardiovascular disease (HR per doubling: 0.51, 95% CI: 0.40 to 0.66, P < 0.001).

Conclusion

Boron may be an overlooked target to improve long-term survival among KTR and potentially other patients, likely through pathways other than inflammation or the methionine-homocysteine cycle that were previously suggested. Interventional trials are warranted to confirm the potential of dietary boron supplementation in KTR and other patient populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02702-0.

Effect of the Boron Concentration in Irrigation Water on the Elemental Composition of Edible Parts of Tomato, Green Bean, Potato, and Cabbage Grown on Soils With Different Textures

The most important environmental source of boron (B) contamination is irrigation water. The data on the effect of B on the elemental composition in the edible parts of vegetables are scarce. A greenhouse pot experiment investigated the effect of irrigation water containing 0.1 and 0.5 mg/L B on the biomass, elemental (e.g., B, Mg, K, Fe, Cu, and Zn) composition, and photosynthetic parameters of tomato (Solanum lycopersicum), green bean (Phaseolus vulgaris), potato (Solanum tuberosum), and cabbage (Brassica oleracea) plants grown on 10 kg of sand, silty sand, or silty soil. The biomass of the edible part was unaffected by B treatment. The soil type determined the effect of B irrigation on the elemental composition of vegetables. The B content increased by 19% in tomatoes grown on silty soil. The 0.1 mg/L B treatment facilitated tomato fruit ripening on all soils, and the 0.5 mg/L B treatment doubled its chlorophyll content index (CCI) on silty soil. The 0.5 mg/L B treatment negatively affected the nutritional value of green beans on all soils, decreasing the Fe and K contents by an average of 83 and 34%, respectively. The elemental composition of potato was unaffected by the treatments, but the CCI of potato leaves increased in the 0.5 mg/L B treatment by 26%. The B content was increased by 39% in cabbages grown on light-textured soils. In conclusion, B concentration of up to 0.5 mg/L in irrigation water had no significant beneficial or adverse effect on the investigated vegetables, but 0.1 mg/L B treatment could shorten tomato fruit maturation time on B-poor soils. The B levels in vegetables remained suitable for human consumption.

Boron Contents of German Mineral and Medicinal Waters and Their Bioavailability in Drosophila melanogaster and Humans

SCOPE

Boron is a trace element that naturally occurs in soil, making mineral and medicinal water important contributors to overall intake. Thus, in a systematic screening, the mean boron concentrations of 381 German mineral and medicinal waters are determined.

METHODS AND RESULTS

Boron concentrations in mineral and medicinal waters are analyzed by inductively coupled mass spectrometry (ICP-MS). Highest boron values find in waters from the southwest of Germany. The boron content of the waters is positively correlated with the concentration of most other analyzed bulk elements, including calcium, potassium, magnesium, and sodium. Mineral waters with either low (7.9 µg L^-1 ), medium (113.9 µg L^-1 ), or high (2193.3 µg L^-1 ) boron content are chosen for boron exposure experiments in fruit flies (Drosophila melanogaster) and humans. In flies, boron-rich mineral water significantly increases boron accumulation, with the accumulation predominantly occurring in the exoskeleton. In humans, serum boron and 24-h urinary boron excretion significantly increase only in response to the intake of boron-rich mineral water.

CONCLUSION

Overall, the current data demonstrate that mineral and medicinal waters vary substantially in the content of boron and that boron-rich mineral water can be used to elevate the boron status, both in flies and humans.

High Content of Boron in Curative Water: From the Spa to Industrial Recovery of Borates? (Poland as a Case Study)

Boron minerals are a sought-after raw material. The European Union’s total dependence on imported borates means that this has been a critical material since 2014. Due to the increased use of borates in modern economies, data on the predicted boron demand in the coming years indicate that it may become a critical element on a global scale. Formerly, the high boron content in groundwater was the basis for qualifying it as medicinal water (boric water). Nevertheless, the current information on the potential toxicity of boron and the narrow margin between deficiency and toxicity of boron in the human body has caused a tightening of the limits of this element in water intended for human consumption. For this reason, metaboric acid has lost its position as a specific component of curative waters. However, despite the fact that boron is not currently a specific component of curative waters, it is found in measureable concentrations in Polish medicinal water considered therapeutic based on other valuable specific components. High boron content in curative water may be the cause of the problems in some spas when obtaining certificates confirming the therapeutic properties of waters. Literature data indicate that waters with high boron content (above 25 mg/L) should not be freely available for drinking in pump rooms and other places in health resorts. To identify the situation with Polish health resorts, the content of boron in 248 curative water samples was analyzed. In 154 of these samples, the boron concentration was relatively low and did not exceed 5 mg/L. However, in the remaining 94 samples, the boron content exceeded 5 mg/L, and 38 samples had boron content exceeding 30 mg/L. Ten of the 248 samples of curative water had a boron concentration above 100 mg/L, which may be a potential source of boron for industrial recovery. The highest concentration of boron was noticed in a water sample from the Wysowa health resort and was 187.6 mg/L. Unfortunately, most of water intakes with a high concentration of boron (above 100 mg/L) are low-yielding wells. Based on the data collected, Rabka appears to be the best candidate for small-scale boron production in terms of boron content and water resources values.

Pivotal role of boron supplementation on bone health: A narrative review

BACKGROUND

Boron is a trace element that plays an important role in numerous biological functions, including calcium metabolism, growth and maintenance of bone tissue. However, there are still no precise indications regarding a possible role of boron supplementation, and its amount of supplementation, to maintain bone health. So the aim of this narrative review was to consider the state of the art on the effectiveness of boron supplementation (alone or with other micronutrients) on growth and maintenance of bone in humans through control of calcium, vitamin D and sex steroid hormone metabolism in order to suggest a daily dosage of boron supplementation.

MAIN FINDINGS

This review included 11 eligible studies: 7 regarding the supplementation with boron alone and 4 regarding supplementation with boron and other nutrients. Despite the number of studies considered being low, the number of subjects studied is high (594) and the results are interesting.

CONCLUSIONS

The studies considered in this narrative review have evaluated the positive effectiveness on bone, in humans, through control of calcium, vitamin D and sex steroid hormone metabolism, considering a dietary supplementation of 3 mg/day of boron (alone or with other nutrients); this supplementation is demonstrably useful to support bone health (in order to prevent and maintain adequate bone mineral density), also considering the daily dose of 3 mg is much lower than the Upper Level indicated by EFSA in the daily dose of 10 mg.

Cost-effective voltammetric determination of boron in dried fruits and nuts using modified electrodes

Cost effective, simple and accurate two voltammetric methods for determination of boron in hazelnut, peanut, almond, raisin, prune and date samples were described. Metal nanoparticles-carbon nanotube modified glassy carbon electrode (MNP/CNT/GCE, M = Au or Cu) and poly xylenol orange modified pencil graphite electrode (p-XO/PGE) were used as working electrodes. The oxidation of alizarin red s (ARS) in the boron-ARS complex at MNP/CNT/GCE and the oxidation of tiron in the B-tiron complex at p-XO/PGE were monitored as response. The limit of determination values (based on visual evaluation) for CuNP/CNT/GCE, AuNP/CNT/GCE and p-XO/PGE were calculated as 100 µg/L, 125 µg/L and 80 µg/L, respectively. The results were compared with the results obtained by inductively coupled plasma mass spectrometric method and no significant difference between the results was observed. The accuracy experiments of the methods and uncertainty calculations were also performed using a certified reference material (UME CRM 1202 Elements in Hazelnut).

Boron-rich diet may regulate blood lipid profile and prevent obesity: A non-drug and self-controlled clinical trial

BACKGROUND

Boron is an element commonly found in nature. The main boron source for organisms is through food and drinking water. In recent years, it is suggested that the "boron-rich diet" can affect human health positively. However, more detailed studies are needed.

OBJECTIVE

The aim of this study was to examine the effect of increased dietary boron intake on some biochemical parameters in humans.

MATERIAL AND METHODS

Thirteen healthy women consumed diets containing 10 mg more boron than their routine diet for one month. This boron intake was provided with the increase of boron-rich foods such as dried fruits, avocado, and nuts in the diet. Some biochemical and hematologic parameters were determined in blood, urine and saliva samples taken before and after a boron-rich diet.

RESULTS

Serum, salivary, and urine boron concentrations increased 1.3, 1.7, 6.0 fold, respectively. The most significant clinically change was found in the lipid profile. Serum total, LDL, VLDL cholesterol, and triglyceride levels decreased significantly. Body weight, body fat weight, and Body Mass Index also decreased. Significant changes in serum TSH and salivary buffering capacity were also found.

CONCLUSION

Increasing the intake of boron through dietary means might contribute to beneficial effects on lipid metabolism, obesity, and thyroid metabolism; salivary boron may reflect serum boron; and boron may be used as a cariostatic agent in dentistry. An increased intake of other dietary factors such as fiber, potassium, iron, vitamin A, and vitamin E in the boron-rich foods might have been responsible of the effects described. To our knowledge, this study is the first clinical study in which dietary boron intake is increased via foods.

Nutritional quality of almond, canarium, cashew and pistachio and their oil photooxidative stability

Daily consumption of nuts is recommended as a part of a healthy diet as they contain protein and are rich in beneficial fatty acids and essential nutrients. The nutritional qualities of nuts are affected by their fatty acid composition and other factors such as maturity. Oil oxidative stability is important to determine nut nutritional quality in terms of fatty acid composition over storage. Therefore, this study aimed to (a) assess the nutritional quality (photooxidative stability and nutrient composition) of almond, cashew, pistachio and canarium (a newly commercialised indigenous nut); and (b) explore differences in nutrient concentrations between immature and mature canarium nuts. A decrease in polyunsaturated fats after photooxidation in almond and pistachio was observed. Canarium oil did not change following photooxidation suggesting canarium may display a long shelf life when stored appropriately. Our study indicated that almond provided over 50% of the recommended daily intake for manganese whereas canarium intake provided 50% of the recommended daily intake for iron (for males). Pistachio was richer in potassium compared with other nuts and canarium was richer in boron, iron and zinc than other nut species. Mature canarium kernels were richer in boron, iron and zinc but contained less potassium than immature canarium. Therefore, the current study recommended to store kernels in dark to decrease oil photooxidation, and maturity of canarium kernels at the harvest time was important affecting nutrient concentrations of kernels.

Boron Content of Some Foods Consumed in Istanbul, Turkey

The boron content was determined in 42 different foods consumed in Istanbul, Turkey. Eleven species of fruit, ten species of vegetable, eight species of food of animal origin, four species of grain, two species of nuts, two species of legume, and five other kinds of foods were included to this study. They were analyzed by two methods: Inductively coupled plasma mass spectrometry (ICP-MS) technique and carminic acid assay, and the results of two methods were also compared. Boron concentration in foods ranged between 0.06-37.2 mg/kg. Nuts had the highest boron content while foods of animal origin had the lowest. A strong correlation was found between the results of the carminic acid assay and the ICP-MS technique (p = 0.0001, Pearson correlation coefficient: r = 0.956). Bland Altman analysis also supported this correlation. ICP-MS is one of the most common, reliable, and powerful method for boron determination. The results of our study show that spectrophotometric carminic acid assay can provide similar results to ICP-MS, and the boron content in food materials can be also determined by spectrophotometric method.

Microelements for bone boost: the last but not the least

Osteoporosis is a major public health problem affects many millions of people around the world. It is a metabolic bone disease characterized by loss of bone mass and strength, resulting in increased risk of fractures. Several lifestyle factors are considered to be important determinants of it and nutrition can potentially have a positive impact on bone health, in the development and maintenance of bone mass and in the prevention of osteoporosis. There are potentially numerous nutrients and dietary components that can influence bone health, and these range from the macronutrients to micronutrients. In the last decade, epidemiological studies and clinical trials showed micronutrients can potentially have a positive impact on bone health, preventing bone loss and fractures, decreasing bone resorption and increasing bone formation. Consequently, optimizing micronutrients intake might represent an effective and low-cost preventive measure against osteoporosis.

Determination of boron contents in water samples collected from the Neelum valley, Azad Kashmir, Pakistan

Intake of boron from food and drinking water may pose a risk to the public health above a certain concentration level. Therefore, knowledge of boron concentration in drinking water and food items is essential. In this context, samples of drinking water were collected from natural springs of the Neelum valley, Azad Kashmir, hit by devastating earthquake in 2005. In these samples, boron concentration was determined using neutron-induced radiography technique. To do so, unknown water samples, along with standard of known boron dried on CR-39 detectors, were irradiated with thermal neutrons. After exposure, CR-39 detectors were etched in 6 M NaOH at 70°C. The tracks produced due to the alpha particles and (7)Li ions as a result of (10)B(n,α)(7)Li reaction were counted under an optical microscope. The tracks produced in theses samples were then related to the boron contents. The measured boron concentration in water samples was found to vary from 0.105 ± 0.005 to 0.247 ± 0.013 mg/l with an average value of 0.17 ± 0.04 mg/l, which are within the acceptable limits.

Estimation of boron intake and its relation with bone mineral density in free-living Korean female subjects

In this study, the status of boron intake was evaluated and its relation with bone mineral density was examined among free-living female subjects in Korea. Boron intake was estimated through the use of the database of boron content in frequently consumed foods by Korean people as well as measuring bone mineral density, taking anthropometric measurements, and surveying dietary intake of 134 adult females in order to relatively evaluate the intake of boron as a nutrient to supplement the low level of calcium intake and to verify its relationship with bone mineral density. Average age, height, and weight of the subjects were respectively 40.84 years, 157.62 cm and 59.70 kg. Also, average bone mineral density of lumbar spine L1-L4 and average bone mineral density of the femoral neck were 0.92 g/cm(2) and 0.80 g/cm(2), respectively. Their average intakes of energy and boron per day were 6,538.53 kJ and 926.94 microg. Intake of boron through vegetables, fruits, and cereals accounted for 61.72% of the overall boron intake. The food item that contributed most to their daily boron intake was rice. Also, 65.41% of overall boron intake was from 30 varieties of other food items, such as soybean paste, soybeans, red beans, watermelons, oriental melons, pears, Chinese cabbage Kimchi, soybean sprouts and soybean milk, etc. Boron intake did not show significant relation to bone mineral density in lumbar vertebra and femoral region. In summary, the average daily intake of boron was 926.94 microg and did not display significant relation to bone mineral density in 134 free-living female subjects. The continuous evaluation of boron consumption by more diverse targets will need to be conducted in the future.

Evaluation of the microelement profile of Turkish hazelnut (Corylus avellana L.) varieties for human nutrition and health

In this study, the levels of boron (B), cobalt (Co), copper (Cu), chromium (Cr), iron (Fe), lithium (Li), nickel (Ni), selenium (Se) and zinc (Zn) microelements in 16 hazelnut samples were determined by inductively coupled plasma mass spectrometry and atomic absorption spectroscopy after microwave digestion, and are discussed for human nutrition and health. Significant differences were observed between the microelement contents of the 16 varieties (P < 0.01). The average microelements concentrations in the varieties varied in the following ranges: B, 13.63-23.87; Co, 0.47-0.82; Cr, 0.22-0.52; Cu, 16.23-32.23; Fe, 31.60-51.60; Li, 0.035-0.042; Ni, 0.58-2.58; Se, 0.96-1.39; and Zn, 22.03-44.03 mg/kg. These results showed that hazelnuts can be an important microelement source for human nutrition and health. According to our trace element data, a daily consumption of 50 g hazelnut can supply easily about 6% for B, 9% for Co, 19% for Fe, 9% for Ni and 16% for Zn of the recommended daily allowance. On the other hand, Se, Cu and Cr levels of 50 g hazelnuts are higher than the respective daily requirements, but slight overdoses of these elements are non-toxic for human health.

Analysis of boron content in frequently consumed foods in Korea

This study analyzed boron content in commonly consumed foods by Koreans. Boron content was analyzed on 299 different foods using inductively coupled plasma atomic emission spectroscopy. The content of boron in cereals, potatoes, starches, sugars, and confectionaries was 1.11 to 828.56 microg per 100 g. As for beans, nuts, and seeds, the content of boron in acorn starch jelly was 66.15 microg per 100 g and in soybeans 1,642.50 microg per 100 g. In fruits, records show 5.29 to 390.13 microg per 100 g. The content of boron in vegetables was 17.45 to 420.55 microg per 100 g and in mushrooms 2.97 to 526.38 microg per 100 g. As for meats, eggs, milks, and oils, it posted 1.48 to 110.01 microg per 100 g. Fishes, shellfishes, and seaweeds contained 1.20 to 6,300.83 microg per 100 g of boron. Beverages, liquors, seasonings, and processed foods posted 1.06 microg per 100 g in corn cream soup and 2,026.49 microg per 100 g in cocoa. It is suggested that the data for the analysis of boron content in foods need to be more diversified and a reliable food database needs to be compiled based on the findings of the study to accurately determine boron consumption.

The significance of dietary boron, with particular reference to athletes

Ergogenic substances and synthetic steroids have a wide spread use, particularly among non-professional athletes. To avoid the side-effect of drug abuse, it is suggested that the key to success is a proper athletic nutrition. It is a balanced intake of nutritional wholesome foods that contain a proper blend of essential nutrients. Knowledge of human physiology and nutrition has increased greatly, and so has application of dietary alterations and supplementation with specific nutrients. Modulation of dietary composition and/or supplementation with specific nutrients with the intent of improving human physical performance is a working definition of nutritional ergogenic aids. Boron is a trace element nutrient, and recently its supplements have been shown to increase the concentration of plasma steroid hormones. In a single blind cross-over trial, it resulted in a significant increase in plasma 17-B estradiol (E2) concentration (P < 0.004) and there was a trend for plasma testosterone (T) levels to be increased. The ratio of E2/T increased significantly. However, there was no perturbation in plasma lipids. Furthermore, the effect of boron on steroidogenesis and its mechanism was also investigated in two more studies conducted on adult male rats. The elevation of endogenous steroid hormones as a result of boron supplementation suggest that boron may be used as an ergogenic safe substance for athletes which should be further investigated.

In vivo and in vitro effects of boron and boronated compounds

Boron is ubiquitously present in soils and water. Associated with pectin it is essential for vascular plants as a component of cell walls, and it stabilizes cell membranes. It is required for the growth of pollen tubes and is involved in membrane transport, stimulating H(+)-pumping ATPase activity and K+ uptake. However, a high boron concentration in the soils is toxic to plants and some boronated derivatives are used as herbicides. An absolute requirement for boron has not been definitively demonstrated in animals and humans. However, experiments with boron supplementation or deprivation show that boron is involved in calcium and bone metabolism, and its effects are more marked when other nutrients (cholecalciferol, magnesium) are deficient. Boron supplementation increases the serum concentration of 17 beta-estradiol and testosterone but boron excess has toxic effects on reproductive function. Boron may be involved in cerebral function via its effects on the transport across membranes. It affects the synthesis of the extracellular matrix and is beneficial in wound healing. Usual dietary boron consumption in humans is 1-2 mg/day for adults. As boron has been shown to have biological activity, research into the chemistry of boronated compounds has increased. Boronated compounds have been shown to be potent anti-osteoporotic, anti-inflammatory, hypolipemic, anti-coagulant and anti-neoplastic agents both in vitro and in vivo in animals.

The nutritional and metabolic effects of boron in humans and animals

We have undertaken studies in humans and animals that aimed to obtain further information about the intake and excretion of boron (B) as well as its effects on markers of coronary heart disease. In humans, we have shown that the intake of B is 2.2 mg/d; its urinary excretion is 1.9 mg/d, and there appears to be little intraindividual variation. Supplementation with 10 mg of B/d resulted in the recovery of 84% of the dose in the urine and a significant increase in plasma estradiol concentration, but no effect on plasma lipoproteins. In rats, increasing the intake of B through the drinking water is reflected in the tissue concentrations, results in an increase in plasma testosterone and vitamin D, and results in a decrease in HDL cholesterol. It is clear that B has the potential to impact significantly on a number of metabolic processes.

Considerations in the determination of boron at low concentrations

Experimental evidence now supports the nutritional essentiality of boron (B) in some biological systems, and accordingly, the need for reliable analytical B data is increasing. However, the accurate determination of B in biological materials is a formidable challenge at low concentrations (<1 mg B/kg). Recent studies still show significant analytical discrepancies in the analysis of animal tissues and fluids, despite the development of instrumental techniques such as TIMS, ICP-MS, ICP-ES, ICAP, SIMS, NA-MS, PGAA, NRA, and so forth, which have demonstrated detection limits approaching or exceeding (microg B/kg concentrations. Since boric acid is both volatile and ubiquitous in nature, the chemical and physical pathways for B contamination and its loss are manifold, especially during sample preparation. An added obstacle is the inadequacy of biological reference materials certified for B below mg B/kg. With an emphasis toward sample preparation and ICP-MS analysis, examples are provided in this article to help the analyst avoid common problems associated with the analysis of B from biological sources. Topics that are discussed include contamination from Teflon vessels during microwave digestion, losses owing to freeze-drying, B isotopic variations, standards preparation, reagent backgrounds, and instrumental interferences.