Elements analysis of infant milk formula by ICP-OES: a comparison of pretreatment methods

Sample pretreatments are critical steps for achieving true and precise results in element analysis for infant milk formula. In this study, we made a comparative study of four pretreatment methods: dry ashing (DA), wet ashing (WA), microwave ashing (MA) and slurry dispersion analysis. Nine elements (Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn) were determined by inductively coupled plasma optical emission spectrometry. Infant formula (GBW08509) with certified values was used for assessment of trueness and precision. The data showed that all relative standard deviations (RSD) of the observed values were <15 %. In contrast to other pretreatment, results for MA had the lowest RSD (≤5 %) for all the elements. For Cu and Mn, there was no significant difference between measurement results and certified values in four pretreatments. But, after DA and WA the results for Ca, K, Na, P and Zn differed significantly from the certified values.     

Chemical characterization of selected metals by X-ray fluorescence method in particulate matter collected in the area of Krakow, Poland

This study presents the results of year long (2007–2008) particulate matter collecting campaigns. The three particle size fractions of particulate matter were collected in Krakow, Poland. Fine fraction consists of particles of a diameter below 2.5 µm, medium is between 2.5 and 8 µm and coarse fraction contains particles above 8 µm. Elemental concentrations were evaluated for each sample. Following elements were measured by EDXRF method: K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Br, and Pb. During each sampling campaign meteorological parameters such as temperature, wind speed, wind direction, humidity were taken from the same place. The highest values of mass particulate matter showed results from January 2008 and April 2008. These were about 14 µg/m³ for fine fraction, 8 µg/m³ for medium and 16 µg/m³ for coarse fraction. The lowest values were observed in May 2007, they were 4, 6, 6 µg/m³, respectively. During the winter season the wind speed was low and particulate matter remained in the air in high concentrations. In May 2007 the speed of wind was higher, reaching 2–3 m/s. PM was blown away from the city from the direction of N–W. Measured concentrations of elements were low, they were below permissible values specified by EU. The coarse fraction concentrations of Ca, Mn, and Fe were higher and characterized by the same trend. These samples were collected when the wind speed was low and its direction was from south-east. As concentrations of Cr, Cu, and Zn were low, these elements did not come from the south-east direction of Krakow. Concentration of Br correlates to the concentration of Pb. It suggests that they came from the same source (vehicles fuels burning).     

Direct determination of toxic trace metals in honey and sugars using inductively coupled plasma atomic emission spectrometry

A rapid method for the determination of Pb, Cd, Cu, Cr, Co, Ni, Mn and Zn in honey and sugars without prior digestion or ashing of the sample was developed, using inductively coupled plasma atomic emission spectrometry (ICP-AES). The critical instrumental parameters such as sample flow rate and radio frequency incident power were thoroughly optimized. The effect of matrix type and its concentration was also examined for glucose/fructose, sucrose and honey matrices. The sensitivity was investigated using calibration curves obtained in presence of the above matrices. The obtained recoveries for Cd, Cu, Cr, Co, Ni and Mn at the μg l⁻¹ level were satisfactory and practically independent of the matrix used for the calibration standards. The recoveries of Pb and Zn were less sufficient. Various commercial samples of honey, sugar, glucose and fructose were analyzed with respect to their toxic metal content. The method can be applied for routine analysis, quality and environmental pollution control purposes at the μg l⁻¹ level of concentration, after suitable dilution of the samples.     

Determination of Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn in red wine samples by inductively coupled plasma optical emission spectroscopy: Evaluation of preliminary sample treatments

A comparative study of sample treatment for removing the organic matter (mainly alcohol) to analyse red wine samples for metal content (Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn) from ICP-OES has been carried out. Thus, three procedures have been assayed before metal analysis: Dry ashing (DA), wet ashing (WA) and the removal of alcohol by evaporation (AR). The obtained results showed that the three methods lead to unbiased recoveries close to 100%. However, the uncertainty of AR method was about twice of the remainder ones. From practical considerations, the DA procedure was considered more suitable for determining metal elements in wine samples by ICP-OES.     

Comparison of sample preparation methods for the ICP-AES determination of minor and major elements in clarified apple juices

Inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for the determination of minor and major elements present in apple juices. Prior to ICP-AES measurement, samples were diluted with nitric acid or digested in a microwave assisted digestion system. The differences in the measured element concentrations after application of different types of sample preparation procedures are discussed. The direct measurement compared to closed microwave dissolution was found to be the best sample preparation procedure. Prior to the measurements the ICP-AES method was validated and optimized for the determination of elements in apple juices. For diluted apple juice samples the lowest limits of detection (LOD) were obtained for Ba and Cd (< 20 μg L^{− 1}), moderate ones for Cu, Mn, Ni, Fe, Ag, Ca, Cr, Zn, Mg, and Sr (20–100 μg L^{− 1}), and the highest LODs for K, Pb, Na, and Al (> 110 μg L^{− 1}). The results obtained for the repeatability (< 0.9%), the intermediate precision (< 4.5%), the day-to-day reproducibility (< 5.2%), and the overall uncertainty of measurement (approx. 4–7%) for all elements analyzed demonstrated the good applicability of the proposed method. Differences in major element content in fresh and commercial apple juice are discussed.     

Fast sequential multi-element determination of Ca,Mg, K,Cu, Fe,Mn and Zn for foliar diagnosis using high-resolution continuum source flame atomic absorption spectrometry: Feasibility of secondary lines,side pixel registration and least-squares background correction

The fast sequential multi-element determination of Ca, Mg, K, Cu, Fe, Mn and Zn in plant tissues by high-resolution continuum source flame atomic absorption spectrometry is proposed. For this, the main lines for Cu (324.754 nm), Fe (248.327 nm), Mn (279.482 nm) and Zn (213.857 nm) were selected, and the secondary lines for Ca (239.856 nm), Mg (202.582 nm) and K (404.414 nm) were evaluated. The side pixel registration approach was studied to reduce sensitivity and extend the linear working range for Mg by measuring at wings (202.576 nm; 202.577 nm; 202.578 nm; 202.580 nm; 202.585 nm; 202.586 nm; 202.587 nm; 202.588 nm) of the secondary line. The interference caused by NO bands on Zn at 213.857 nm was removed using the least-squares background correction. Using the main lines for Cu, Fe, Mn and Zn, secondary lines for Ca and K, and line wing at 202.588 nm for Mg, and 5 mL min^− 1 sample flow-rate, calibration curves in the 0.1–0.5 mg L^− 1 Cu, 0.5–4.0 mg L^− 1 Fe, 0.5–4.0 mg L^− 1 Mn, 0.2–1.0 mg L^− 1 Zn, 10.0–100.0 mg L^− 1 Ca, 5.0–40.0 mg L^− 1 Mg and 50.0–250.0 mg L^− 1 K ranges were consistently obtained. Accuracy and precision were evaluated after analysis of five plant standard reference materials. Results were in agreement at a 95% confidence level (paired t-test) with certified values. The proposed method was applied to digests of sugar-cane leaves and results were close to those obtained by line-source flame atomic absorption spectrometry. Recoveries of Ca, Mg, K, Cu, Fe, Mn and Zn in the 89–103%, 84–107%, 87–103%, 85–105%, 92–106%, 91–114%, 96–114% intervals, respectively, were obtained. The limits of detection were 0.6 mg L^− 1 Ca, 0.4 mg L^− 1 Mg, 0.4 mg L^− 1 K, 7.7 µg L^− 1 Cu, 7.7 µg L^− 1 Fe, 1.5 µg L^− 1 Mn and 5.9 µg L^− 1 Zn.     

矿区植物重金属元素测定的两种前处理方法比较

分别采用酸消解法和干灰化法处理16种矿区植物,并用原子吸收分光光度法测定其中的Mn、Cd、Cr和Zn的含量。结果表明:除Cd外,两种处理方法对Mn、Cr、Zn的测定结果有明显影响。测定植物组织Cd时,两种处理方法都可采用;测定Mn、Cr元素,采用酸消解法较为合适;测定Zn则宜采用干灰化法,并可适当延长木质部分(根、茎)的灰化时间。     

Liquid chromatography/tandem mass spectrometry studies of the phenolic compounds in honey

An improved and simplified analytical method which offers rapid, accurate determination and identification of phenolic compounds in honey samples is reported. The honey samples were diluted by acidified water (pH 2), and analyzed by HPLC–ESI-MS/MS. Simultaneously determination of phenolic acids and flavonoids was carried out by a liquid chromatography–mass spectrometry. Comparison between atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) was performed by analysis of standards. Fragmentation of analytes for subsequent selective Multiple Reaction Monitoring (MRM) analysis was investigated in negative mode. Sample preparation without separation of sugars and clean-up procedure, followed by fast chromatographic separation using a narrow-bore column C18 (50 mm × 2.1 mm, 3 μm) allowed the analysis to be completed in a short run time. LODs were ranged between 1 and 15 ng L⁻¹ for p-coumaric acid and naringenin, respectively. The method was applied for determination of phenolic acids and flavonoids in honey samples from different botanical origin.     

Determination of Zn, B, Fe, Mg, Ca, Na and Si in anisette samples by inductively coupled plasma atomic emission spectrometry

A comparative study of several digestion methods of anisette samples has been carried out. Two dry ashing (DA) treatments as well as four wet ashing (WA) procedures using different mixtures of acids were applied for the sample mineralisation before analysis. Once the anisette samples were mineralised, the contents of Zn, B, Fe, Mg, Ca, Na and Si were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Each method has been studied statistically and also attending to their feasibility. After performing the optimisation of the different treatments tested, it was concluded that one wet ashing method employing a HNO₃:H₂O₂ (10:1) mixture was the most suitable. This method was applied to the analysis of anisette samples. Na, Ca, Mg and Si were present in concentrations up to 215 mg l⁻¹ for Na, 11.6 for Mg, 6.2 for Ca and 5.1 for Si. Fe and B concentrations were not higher than 0.12 mg l⁻¹ and lower for Zn.     

Radioisotope excited EDXRF analysis of sediment core samples from the southern part of the Black Sea +

In all 43 sediment samples were collected as gravity cores in depthfrom 70 to 150 cm, from the 20 sampling sites of the continental slope ofthe southern part of the Black Sea, during 1978. The samples were quantitativelyanalyzed by radioisotope excited energy dispersive X-ray fluorescence spectrometry(EDXRF) using fundamental parameter technique (FTP). The investigated sedimentsamples were the organic rich-mud components of the core samples, which wereknown as rich in metals. The metal concentration ranges were as follows: Ca(3.1–12.9%), Ti (1000–2000 µg/g), V (40–150 µg/g),Cr (30–200 µg/g), Mn (200–1500 µg/g), Ni (25–100µg/g), Cu (20–70 µg/g), Zn (20–50 µg/g), Br(15–670 µg/g), Rb (5–90 µg/g), Sr (80–700 µg/g),Y (10–20 µg/g), Mo (10–111 µg/g), Zr (20–190µg/g), Cd ( <1–5 µg/g), Sb ( <1–5 µg/g),I (10–430 µg/g), Ba (100–1650 µg/g), La (5–18µg/g), Ce (12–38 µg/g) and Nd (6–17 µg/g). Thesediment cores systematically collected in 1978 by Mineral Research and ExplorationInstitute of Turkey (MTA) are the oldest available sediment samples from theTurkish coastline of the Black Sea. Therefore, the results may be used asreferences for monitoring possible future metal pollution.     

On-line pre-concentration of Cr(III) and Mn(II) in FI-FAAS: A critical study involving interference effects and analytical use of an immobilized 8-hydroxyquinoline minicolumn

A flow injection system with a pre-concentration minicolumn based on a chelating resin was coupled to a flame atomic absorption spectrometer. The focus of this work was the investigation of interference effects and the analytical applicability of the azo-immobilized 8-hydroxyquinoline on controlled-pore glass for the determination of Cr and Mn in mussel and non-fat milk powder. All studied concomitants affected the retention of Cr(III). These effects are probably related to the formation of hydroxo-complexes at the optimum pH range 9.0-10. The positive effect caused by Ca(II) was exploited to increase the retention of Cr(III) species and to improve the slope by 70%. The interferences on Mn(II) retention were less severe. The quantification of Cr and Mn was performed by standard additions. The proposed methodology was validated by analysis of three certified reference materials of mussels (Cr and Mn) and non-fat milk powder (Mn) with a mean relative percent error of <6.5% and mean relative standard deviation of <13%. Chromium and Mn were determined in typical Chilean mussels samples, and Mn was determined in non-fat milk powder samples. Results agreed at the 95% confidence level with those obtained by electrothermal atomic absorption spectrometry (ETAAS) using graphite furnace atomization. The method detection limits for a 30 s pre-concentration time were 0.9 and 1.1 micro g L(-1) for Mn, and 2.2 and 2.5 micro g L(-1) for Cr in acid digested solutions of mussel and non-fat milk, respectively. The methodology is simple, fast (sampling frequency 60-72 h(-1)), reliable, of low cost, and can be applied to the determination of traces of Cr (> or =0.18 micro g g(-1)) and Mn (> or =0.6 micro g g(-1)) in mussel samples, and Mn (> or =0.37 micro g g(-1)) in non-fat milk powder.     

Determination of mineral constituents in duplicate portion diets of two university student groups by instrumental neutron activation

Concentrations of 15 elements were determined simultaneously in duplicateportion diets of two university student groups from So Paulo Universityconsisting of nine women (20–23 years) and ten men (20–24 years).Thediet samples were prepared by either freeze-drying or drying in a ventilatedoven. About 100–200 mg of diets were irradiated for 2 minutes and 8hours in the IEA-R1m research reactor and Br, Ca, Cl, Co, Cr, Cs, K, Fe, Mn,Mg, Mo, Na, Rb, Se, and Zn were determined by instrumental neutron activationanalysis (INAA). The average daily intakes found in the women and men groupswere: 2.1 and 4.3 mg of Br, 501 and 707 mg of Ca; 3.1 and 6.0 g of Cl; 12and 25 mg of Co; 15 and 36 µg of Cs; 53 and 63 µg of Cr; 5.1 and10.8 mg of Fe; 1.3 and 2.8 g of K; 134 and 306 mg of Mg; 1.3 and 4.1 mg ofMn; 134 and 302 mg of Mo, 2.0 and 4.1 g of Na; 2.4 and 4.6 mg of Rb; 29 and41 µg of Se; 6.2 and 10.6 mg of Zn, respectively. The daily intakesof Ca, Se and Zn in both groups and Fe in the women groups appeared to bebelow the U.S. RDA recommendations. For the elements Na and Cl the daily intakeswere higher than the recommended values by RDA.     

Liquid chromatography–tandem mass spectrometry reveals the widespread occurrence of flavonoid glycosides in honey,and their potential as floral origin markers

HPLC-MS–MS analysis of unifloral honey extracts has shown the occurrence of flavonoid glycosides in most of the analyzed samples. These compounds are not present in large amounts, but can reach up to 600 μg/100 g honey in canola and rapeseed honeys. Rhamnosyl-hexosides (tentatively rutinosides and neohesperidosides) and dihexosides (hexosyl(1→2)hexosides and hexosyl(1→6)hexosides) of flavonols such as quercetin, kaempferol, isorhamnetin and 8-methoxykaempferol, are the main flavonoid glycosides found in honey. However, flavonoid triglycosides and monoglycosides are also detected in some floral origins. Eucalyptus and orange blossom nectars were collected and analyzed showing that nectar flavonoid glucosides, as is the case of eucalyptus flavonoids, can be readily hydrolyzed by the bee saliva enzymes, while flavonoid rhamnosyl-glucosides, as is the case of citrus nectar flavonoids, are not hydrolyzed, and because of these reasons the flavonoid glycoside content of citrus honey is higher than that of eucalyptus honey that contains mainly aglycones. The flavonoid glycoside profiles detected in honeys suggest that this could be related to their floral origin and the results show that the HPLC-MSn ion trap analysis of flavonoid glycosides in honey is a promising analytical method to help in the objective determination of the floral origin of unifloral honeys.     

Cold plasma ashing improves the trace element detection of single Daphnia specimens by total reflection X-ray fluorescence spectrometry

The recently developed dry method for the element determination of single freshwater microcrustacean specimens (Daphnia) using total reflection X-ray fluorescence (TXRF) spectrometry showed that inhomogeneities of the biological material on the glass carriers resulted in some cases in high background and hampered the detection of certain trace elements (e.g. Cr, Ni). The aim of this study was to test how inhomogeneities of the biological material can be reduced using cold plasma ashing (CPA) techniques. For that, single specimens of the microcrustacean Daphnia pulex prepared according to the dry method were measured by TXRF before and after CPA. To determine the efficiency of the removal of organic matrix, the background and signal-to-background relationship of 28 samples were analyzed. The results showed (1) a highly significant reduction of the background by CPA fluctuating between 26 and 46% (all elements) and (2) a significant increase of the signal-to-background relationship by the factor 1.5–2.5 (all elements) and a much better detection of Cr, Pb, As and Se. The element concentrations (with exception of Cr, Ni and Pb) after ashing were in the same range or slightly higher than that before ashing. No significant differences between the two treatments were observed for Mn, As, Pb, Se (November), Sr (November), Cr (March) and Pb (March). The element concentration of P, K, Ca, Cu, Zn, Cr (November), Fe and Rb were significantly higher after ashing. In general, they increased by 1.5–13.6% and were highest for Rb (March) and P (November). In contrast, the element concentration of Ni and Cr (only March) decreased significantly after ashing (Ni: 91.6–92.1%, Cr: 91.3%). We recommend the use of CPA for biological material in the microgram-range as a routine method for TXRF analysis, especially when trace elements in minute concentrations are of interest.     

液相色谱-串联质谱法测定蜂产品中吡虫啉及其3种代谢物

建立了蜂蜜和蜂花粉中吡虫啉及其代谢物吡虫啉烯烃、吡虫啉脲、6-氯烟酸的液相色谱-串联质谱(LC-MS/MS)检测方法.在QuEChERS方法基础上,针对目标物化学性质和样品杂质情况,对提取溶液的pH值、提取次数、净化材料等参数进行了优化.最终以5％甲酸-乙腈溶液提取两次,无水MgSO4、NaCl盐析分层,提取液经增强型脂类去除材料(EMR)净化,以LC-MS/MS进行测定,基质外标法进行定量分析.结果表明,蜂蜜和蜂花粉中吡虫啉、吡虫啉烯烃、吡虫啉脲、6-氯烟酸的平均加标回收率为86.0％～111.5％, 相对标准偏差在1.7％～9.6％之间, 检出限分别为0.20, 3.50, 0.40和14.00 μg/kg,定量限分别为0.60, 11.64, 1.20和45.00 μg/kg.本方法分析速度快、灵敏度高、重现性好,适用于蜂蜜和蜂花粉中吡虫啉及其3种代谢物的快速测定.     

Evaluation of the use of multiple lines for determination of metals in water by inductively coupled plasma optical emission spectrometry with axial viewing

Inductively coupled plasma optical emission spectrometers (ICP OES) allow fast simultaneous measurements of several spectral lines for multiple elements. The combination of signal intensities of two or more emission lines for each element may bring such advantages as improvement of the precision, the minimization of systematic errors caused by spectral interferences and matrix effects. In this work, signal intensities for several spectral lines were combined for the determination of Al, Cd, Co, Cr, Mn, Pb, and Zn in water. Afterwards, parameters for evaluation of the calibration model were calculated to select the combination of emission lines leading to the best accuracy (lowest values of PRESS–Predicted error sum of squares and RMSEP–Root means square error of prediction). Limits of detection (LOD) obtained using multiple lines were 7.1, 0.5, 4.4, 0.042, 3.3, 28 and 6.7 µg L^− 1 (n = 10) for Al, Cd, Co, Cr, Mn, Pb and Zn, respectively, in the presence of concomitants. On the other hand, the LOD established for the most intense emission line were 16, 0.7, 8.4, 0.074, 23, 26 and 9.6 µg L^− 1 (n = 10) for these same elements in the presence of concomitants. The accuracy of the developed procedure was demonstrated using water certified reference material. The use of multiple lines improved the sensitivity making feasible the determination of these analytes according to the target values required for the current environmental legislation for water samples and it was also demonstrated that measurements in multiple lines can also be employed as a tool to verify the accuracy of an analytical procedure in ICP OES.     

Trace element determination in thorium oxide using total reflection X-ray fluorescence spectrometry

Applicability of Total Reflection X-ray Fluorescence (TXRF) spectrometry for the determination of trace metals at concentration of µg/g level in thorium oxide was studied. The TXRF spectrometer was calibrated using a multielement standard solution and the method was validated by analyzing another multielement standard solution. Sample preparation conditions were optimized for the TXRF determinations of trace metals in thorium oxide. The elements K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Ba and Pb present in thorium oxide standards were determined after dissolving them in HNO₃/HF mixture and separating the bulk matrix, thorium, by solvent extraction using tri-n-butyl phosphate (TBP) and tri-n-octyl phosphine oxide (TOPO) as extractants. A comparison of TXRF determined concentrations of trace elements Ca, V, Cr, Mn, Fe, Ni and Cu with the certified values shows that TXRF determined concentrations have an RSD of 20% (1 s for n = 4) and are within an agreement of 20% of the certified values in most of the cases.     

用ICP研究鹿科动物骨质疏松症的微量元素特征

鹿科动物的骨质疏松症是近几年出现的一种疾病，它影响鹿的生长发育和繁殖，病重者死亡。我们采集梅花鹿和白唇鹿的毛，血样，用低温灰化方法和温法消解处理样品，用ＩＣＰ分析了毛，血清中微量元素的含量。病梅花鹿毛样中Ｍｇ，Ａｌ，Ｃａ，Ｔｉ，Ｆｅ，Ｃｕ，Ｚｎ的含量比正常组高，Ｔｉ，Ｃｕ，Ｚｎ的偏差率大于１５％，而Ｓｉ，Ｍｎ，Ｐ，Ｐ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ比正常组低，Ｖ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ存在...     

气相色谱-负化学源质谱法测定蜂蜜和王浆中4种杀虫剂的残留

建立了气相色谱-负化学源质谱（GC-NCI/MS）测定蜂蜜和王浆中4种杀虫剂残留量的方法。蜂蜜样品由乙酸乙酯提取、乙二胺-N-丙基硅烷（PSA）净化,而王浆样品经乙腈-水（1：1,v/v）提取、C18固相萃取柱净化,采用GC-NCI/MS测定,外标法定量。结果表明：在50~500 μg/L范围内4种农药的线性良好;所有农药的LOD在0.12~5.0 μg/kg之间,LOQ在0.40~16.5 μg/kg之间;在10、15、20 μg/kg 3个添加水平下,4种农药的平均回收率在78.2%~110.0%之间,且RSD均小于14%。所有农药的测定均没有出现干扰峰。该方法简单、快速,准确度、精密度和选择性高,抗干扰能力强,可用于蜂蜜和王浆中这4种农药的快速检测。     

Total reflection X-ray fluorescence spectrometric determination of elements in water hyacinth from the Lerma River

The Lerma River is one of the most polluted body water in Mexico. For this reason, only the highly resistant organisms such as water hyacinth are able to reproduce in this river. The aim of this work was to evaluate the concentration of K, S, Fe, Ca, Mn, Ti, Zn, Sr, Rb, Cu, Cr, Ni, Pb and Br in roots of water hyacinth (Eichhornia crassipes) from the Lerma River. The samples were collected from five sites in the river and analyzed in triplicate using a TXRF Spectrometer ‘TX-2000 Ital Structures’ with a Si(Li) detector and a resolution of 140 eV (FWHM) at Mn Kα. A Mo tube (40 kV, 30 mA) with 17.4 KeV excitation energy was used for a counting time of 500 s. Results show that the average metal concentration in the water hyacinth roots decrease in the following order: K (9698.2 µg/g) > S (7593.3 µg/g) > Fe (4406.6 µg/g) > Ca (2601.8 µg/g) > Mn (604.2 µg/g) > Ti (230.7 µg/g) > Zn (51.65 µg/g) > Sr (43.55 µg/g) > Rb (18.61 µg/g) > Cu (12.78 µg/g) > Cr (6.45 µg/g) > Ni (4.68 µg/g) > Pb (4.32 µg/g) > Br (4.31 µg/g) and the bioconcentration factors in the water hyacinth decrease in the sequence: Ti > Fe > Mn > Cu > Ni > Zn > S > Pb > Rb > K > Cr > Sr > Br > Ca. The concentrations in roots of water hyacinth reflect the high pollution level of the river.