Fractionation of tropical soilborne heavy metals—Comparison of two sequential extraction procedures

We compared Cr, Cu, Ni and Zn fractionation patterns in four typical soils naturally containing high levels of these elements on the tropical volcanic island of Réunion. Two sequential chemical extraction procedures were used: the modified four-stage BCR procedure (subsequently called mBCR) and the modified six-stage Geological Survey of Canada procedure (subsequently called mGSC). The results obtained by these two procedures highlighted some similarities. With both approaches, exchangeable fractions were the smallest fractions with respect to the four heavy metal (HM) distributions (< 5% of the total HM quantity), and residual fractions had the highest Cr, Cu, Ni and Zn contents (39.1–97.9%) in the four soils. In contrast, we noted differences in HM fractions bound to organic matter. These differences could be explained by the different reagents and extraction sequences implemented in the two procedures. However, the most marked difference in the results obtained by the two procedures concerned the HM fraction bound to oxyhydroxides, despite the fact that the same reagent was used (hydroxylammonium chloride). Our results revealed that the mBCR procedure underestimated the proportion of HM bound to this fraction. The mGSC procedure therefore seems more suitable for analysing tropical soils which typically contain high levels of Fe and Mn oxyhydroxides.     

A simple non‐atomic absorption procedure for determining the effective cation exchange capacity of tropical soils

Abstract

A simple non‐atomic absorption procedure for determining the effective cation exchange capacity of tropical soils has been developed. The method involves the shaking of soil samples (10g) with ammonium chloride (3 x 25 cm³, 1 mol/L) to displace the exchangeable cations. The soil is then equilibrated with dilute ammonium chloride (3 x 25 cm³, 0.01 mol/L). After the final equilibration the ammonium ions retained by the soil are determined to facilitate the calculation of the ECEC. Data obtained for 22 tropical soils ranging in ECEC values from 1–50 cmol(+)/kg show a highly significant correlation with values derived using the compulsive exchange or summation procedures. The silver thiourea procedure data gave significantly poorer correlations with that obtained using all three of the above methods.     

The determination of ammonium and chloride by an auto‐analyser for the measurement of cation exchange capacity of soils

Abstract

An auto‐analyser method has been developed for the simultaneous determination of NH₄ ⁺ and Cl^‐ in Ca(NO₃)₂/KNO₃ extracts of NH₄Cl treated soils for cation exchange capacity measurements. The method gives satisfactory agreement with manual titration procedures.     

Temporal and spatial distributions of nitrate‐nitrogen in two furrow‐irrigated semiarid soils amended for sludge and fertilizer

Abstract

A statistical comparison of data collected from two cotton production fields with a history of either commercial fertilizer or sludge amendments showed significantly different nitrate‐nitrogen (N) concentrations in time and space. The sludge‐amended field had high nitrate concentrations in the root zone (1.5 m) throughout the season. Whereas, the fertilized field showed low nitrate‐N concentrations during the same period. Both fields showed significant increases in nitrate‐N following pre‐plant irrigation events, and significant decreases of nitrate‐N in the root zone during the growing season. Following harvest, the sludge‐amended field had very large reserve of nitrate‐N in the profile. The spatial variabilities, as determined by the % coefficients of variations (CVs) of eight cores per sampling event, of nitrate‐N distributions where large in both fields, 69% and 90% for the sludge and fertilizer field, respectively. The estimated nitrate‐N leaching losses were much higher in the sludge‐amended than the fertilized field. Significant leaching losses in the sludge‐amended field were likely the result of year‐to‐year sludge residue accumulations that mineralize and release nitrate‐N in the zone of incorporation (0–30 cm).     

Residual heavy metal concentrations in sludge‐amended coastal plain soils ‐ I. Comparison of extractants

Abstract

The purposes for this research were: to examine the long‐term residual effects of farmland applications of municipal sludges from four treatment technologies on the total and extractable Zn, Cu, Mn, Fe, Pb, Ni and Cd concentrations in Coastal Plain soils; to investigate the effects of sludge sources and rates on the effectiveness of soil extractants to remove the various metals; and to determine correlation coefficients for soil extractable versus plant accumulation in tobacco. The extractants evaluated were Mehlich 1 and 3, and DTPA‐pH 7.3. Composite Ap horizon soil samples and tobacco leaf samples were obtained in 1984 from research plots at two sites in Maryland that were established in 1972 and 1976, respectively, using sludge materials from three wastewater treatment facilities in the Washington, D.C. metropolitan region. Similar application rates were used at both sites.

A wide range in soil pH values was found among treatments at each site. Significant (p ≤ 0.05) increases were observed in total Zn, Cu, Fe, Pb, Ni, and Cd for all sludge sources with increased rates; however, values for total soil Mn exhibited high variability in all cases. The rankings among the extractants varied for some elements depending on the sludge sources. For Zn, the rankings were Mehlich 1 > Mechlich 3 > DTPA‐pH 7.3 across all sources and rates. For Cu, Mehlich 3 > Mehlich 1 > DTPA‐pH 7.3 was found for soils amended with Blue Plains digested (BPD) and Piscataway limeddigested (PLD) sludges but Mehlich 1 ≥ DTPA pH 7.3 > Mehlich 3 for Blue Plains limed compost (BPLC) and Annapolis Fe and heat treated (AFH) sludges. Concerning extractable Mn, Mehlich Mehlich 1 > Mechlich 3 > DTPH pH 7.3 was the order for BPLC and AFH sludges but Mehlich 3 > Mehlich 1 > DTPA‐pH 7.3 was observed for BPD and PLD sludges. The rankings among extractants for Fe (Mehlich 3 > Mehlich 1 > DTPA‐pH7.3), Ni (Mehlich 3 ≥ Mehlich 1 > DTPA‐pH 7.3), Pb (Mehlich 3 > DTPA‐pH 7.3 > Mehlich 1) and Cd (Mehlich 1 > Mehlich 3 > DPTA‐pH7.3) were somewhat similar across all sludge sources. Significant correlation coefficients were obtained for all three extractants for soil extractable vs. plant Zn, Cu, Ni, and Cd at both sites; however, Mehlich 3 was not significant for Mn. Also, neither of the extractants produced significant coefficients for Fe and Pb.     

Evaluation of efficient soil test methods for Zn and their critical vales in salt‐affects soils for rice

Abstract

Soil pot culture experiment was conducted on 22 soils of Balewal‐Phaguwala‐Narike (BPN) and 24 soils of Isri‐Langrian‐Narike (ILN) associations using rice (PR 106) as test crop at 0 and 7.5 ppm Zn levels. Chelating extractants 0.005M DTPA, 0.01M EDTA‐(NH₄)₂CO₃ and 0.05M EDTA, extracted more soil Zn than double‐acid and were significantly correlated with each other as well as with soil pH and clay in BPN and only with clay in ILN soil association. Soil CaCO₃ governed the double‐acid extractable Zn in these soils. Dry matter yield and Zn uptake by rice significantly increased with 7.5 ppm Zn application. The response was higher in ILN than BPN soil association, The DTPA method gave the highest correlation with Bray's yield and Zn uptake (r =0.72 and 0.55) followed by 0.05M EDTA (r ‐ 0.75 and 0.61) or EDTA‐(NH₄)₂CO₃ (r =0.70 and 0.61). The predictability of rice yield improved from 18–27 to 27–35, 32–43, 34–44 and 51–55 percent as a result of stepwise inclusion of pH, CaCO₃, organic carbon (OC) and clay respectively in the regression equation alongwith Zn extracted by chelating agents.

The critical levels of DTPA, EDTA‐(NH₄)₂CO₃ and EDTA extractable Zn significantly differed in the two associations and were 0.69, 0.82 and 1.24 ppm in BPN and O.BC, 1.09 and 1.42 ppm in ILN soil association. Soil properties further affected the critical levels. This for DTPA available Zn was 0.80 and 1.03 ppm in soil containing less and greater than 2% CaCO₃, 1.03 and 0.80 ppm in soils containing less and greater than 0.25% OC. These values for EDTA‐(NH₄)₂CO₃ available Zn were 1.09 and 0.91 ppm Zn in soils containing less and greater than 15% clay suggesting that critical levels of Zn for each category of soil properties should be considered while making recommendations of Zn fertilization of crops.,     

Nitric acid dissolution and multi‐element analysis of soils and sediments by inductively coupled plasma spectrometry

Abstract

A method was developed for the simultaneous analysis of P, K, Cu, Cd, Zn, Fe, Mn and Pb in soils and sediments by inductively coupled plasma spectrometry (ICP) after digestion in nitric acid. The procedure extracted 82 to 94% of the totals of the heavy metals, 78% of total P and 34% of total K. Inter‐element interference correction data are given for the ICP method. The method gave results similar to those obtained by other analytical procedures. The precision of the method was satisfactory but was lowest for Cd which had the lowest concentrations (<2.7 mg/kg) of the elements determined.     

Prediction of available heavy metals by six chemical extractants in a sewage sludge‐amended soil

Abstract

In a field experiment conducted during three years in a sandy‐loam, calcareous soil, one aerobically digested sewage sludge (ASL) and another anaerobically digested sewage sludge (ANSL) were applied at rates of 400, 800, and 1,200 kg N/ha/year, and compared with mineral nitrogen fertilizer at rates of 0, 200, 400, and 600 kg N/ha/year in a cropping sequence of potato‐corn, potato‐lettuce, and potato, the first, second, and third year, respectively. Results showed that the highest values of soil extractable metals were obtained with aqua regia, whereas the lowest levels with DTPA. All metal (Zn, Cu, Cd, Ni, Pb, and Cr) gave significant correlations between metal extracted with the different extractants and metal loading applied with the sludges. The metal extractable ion increased over the control for Zn, Cu, Cd, Ni, Pb, and Cr extracted with DTPA, EDTA (pH 8.6) and 0.1 N HC1, for Zn, Cd, Ni, Pb, and Cr extracted with EDTA (pH 4.65) and AB‐DTPA, and for Zn, Cd, Ni, and Cr extracted with aqua regia. The level of metal‐DTPA extractable resulted highly correlated with that obtained by the other methods, except the Ni‐aqua regia extractable. The soil extractable elements which showed significant correlations with metals in plant were: Zn, Cu, Cd, and Ni in potato leaves, Cd, Ni, and Pb in corn grain, and Zn and Cd for lettuce wrapper leaves. In general, all the chelate based extractants (DTPA, EDTA pH 4.6, EDTA pH 8.6, AB‐DTPA) were equally useful as indicator of plant available metals in the soil amended with sludge.     

A new soil test method for the determination of plant‐available cadmium in soils

Abstract

A new soil test procedure using 1M NH₄Cl was developed for the extraction of plant‐available cadmium (Cd) from soils. Five grams of soil is weighed into a 50‐mL polyethylene vial to which 30 mL of 1M NH₄Cl solution is added. The soil suspension is then shaken on a horizontal shaker for 16 h at 25°C at 180 cycles per min. The suspension is then centrifuged at 2,500g for 5 min and the supernatant filtered through a 0.45 μm nitrocellulose filter under vacuum. Cadmium in the extract is then determined at 228.8 nm on a graphite furnace equipped atomic absorption spectrophotometer. A highly significant correlation was observed between the natural logarithm (In) of 1M NH₄Cl‐extractable Cd in soils and the Cd content in the grain of durum wheat (Triticum turgidum var. durutn L.) grown on the same soils (r = 0.974, p = 3.8 x 10^‐7). In comparison with several commonly used extradants, such as ABDTPA, CaCl₂, NH₄OAc, and NH₄NO₃, the 1M NH₄Cl‐extracted Cd from soils was found to be a better index of Cd availability.     

Semi‐micro determination of total phosphorus in soils,sediments, and organic materials: A simplified perchloric acid digestion procedure

Abstract

A semi‐micro modification of perchloric acid digestion method for the determination of total P in soils, sediments, and organic materials is described. Samples are digested for 30 minutes with nitric acid at 115 °C and then for 2 hours with perchloric acid at 170 °C in an aluminum heating block. After dilution, samples are hydrolyzed at 100 °C for 1 hour in order to decompose pyrophosphate, and the liberated orthophosphate is determined without a neutralization step by the phosphomolybdate blue method of Murphy and Riley (1962). Comparability with the method of Sommers and Nelson (1972) is demonstrated using nine samples of different types. The same reaction conditions of digestion and color development as in the determination of total P in waters (Kopá?ek and Hejzlar, 1993) enable a comparable estimate of total P in solid and water samples in complex environmental studies.     

Evaluation of microplate and bench-scale β-glucosidase assays for reproducibility, comparability, kinetics, and homogenization methods in two soils

Enzyme assays that use fluorescently labeled substrates and microplate formats have been incorporated into laboratory protocols to improve sensitivity and reduce the time and labor involved in traditional bench-scale analyses. Microplate protocols vary, and the methods have not been evaluated systematically for comparability and reproducibility. In this study, p-nitrophenol (pNP)-based and 4-methylumbelliferone (MUF)-based microplate methods for estimating β-glucosidase activity were compared in two soils with different properties. Microplate method reproducibility was evaluated in replicate soil suspensions, and Michaelis–Menten kinetics for the microplate assays were compared to those of a standard pNP bench-scale assay. The effect of soil sample sonication on reproducibility was determined for the MUF microplate method. The MUF microplate method was reproducible in five replicate soil suspensions, but the pNP microplate method showed greater variability. The K _m Michaelis–Menten constant was significantly different in the microplate methods compared to the bench method. Enzyme activities measured by the MUF and bench methods were comparable, but the pNP microplate method resulted in more variable measurements and was less sensitive in the soils studied. Sonication of soil at an intensity of 15 W ml^?1 resulted in higher (MUF) measurements, but greater variability. The effects of high background absorbance on the reproducibility, sensitivity, and accuracy of the pNP microplate method do not support this method as a substitute for the standard bench method. A robust comparison study of the MUF microplate method across laboratories is recommended to further validate its use in comparative analyses.     

A simple method for determination of ammonium in semimicro‐Kjeldahl analysis of soils and plant materials using a block digester

Abstract

A simple method for determination of ammonium in semimicro‐Kjeldahl analysis of soils and plant materials using a Tecator or Technicon 40‐tube block digester is described. It involves use of an inexpensive steam distillation apparatus that permits direct distillation of ammonium from the tubes used for Kjeldahl digestion in 40‐tube block digesters. The method is rapid and precise, and it gives results that agree closely with those obtained by the customary method of ammonium N analysis involving transfer of the Kjeldahl digest before distillation.     

Proposal of a simple screening method for a rapid preliminary evaluation of “heavy metals” mobility in soils of contaminated sites

Purpose  

Risks associated to “heavy metals” (HM) soil contamination depend not only on their total content but, mostly, on their mobility. Many extraction procedures have been developed to evaluate HM mobility in contaminated soils, but they are generally time consuming (especially the sequential extraction procedures (SEPs)) and consequently applicable on a limited number of samples. For this reason, a simple screening method, applicable even “in field”, has been proposed in order to obtain a rapid evaluation of HM mobility in polluted soils, mainly focused on the fraction associated to Fe and Mn oxide/hydroxides.     

Sodium bicarbonate‐DTPA test for macro‐and micronutrient elements in soils

Abstract

Individual soil tests are used to assess plant nutrient element needs. Separate soil tests, however, are time consuming and costly. Our objective was to develop a 0.5M sodium bicarbonate (NaHCO₃) soil phosphorus (P) test in combination with 0.005M diethylenetriaminepentaacetic acid (DTPA) so macronutrient dements: ammonium‐nitrogen (NH₄‐N), nitrate‐nitrogen (NO₃‐N), P, potassium (K), calcium (Ca), and magnesium (Mg); and micronutrients: iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) could be quantified in one extraction. The NaHCO₃‐DTPA extracting solution is a combination of 0.5M NaHCO₃ and 0.005M DTPA and has a pH of 7.60±0.05. Sodium in the solution enhances the NH₄, K, Ca, and Mg extraction; bicarbonate (HCO₃) is for P extraction; DTPA chelates Ca, Mg, and micronutrients; and the water is for NO₃ extraction. Soil samples (0–15 cm depth) came from two sources. The first set was from 12 N x P dryland proso millet (Panicum miliaceum L.) experiments, conducted from 1985 through 1987 in eastern Colorado. These soils were extracted with potassium chloride (KCl), NaHCO₃, ammonium acetate (CH₃‐COONH₄), DTPA, ammonium bicarbonate DTPA (AB‐DTPA), and with the NaHCO₃‐DTPA solutions. The second set included 25 soils from Alabama, Georgia, North Carolina, and South Carolina and were analyzed only for available P with the NaHCO₃ and NaHCO₃‐DTPA methods. Simple linear correlations for macronutrient elements and micronutrients were highly significant. Critical levels for the macronutrient elements: NO₃‐N, P, and K were 27, 11, and 144 mg kg^‐1, respectively; and the critical levels for the micronutrients: Fe, Mn, Zn, and Cu were 3.9, 0.35, 0.97, and 0.24 mg kg^‐1, respectively.     

Coupling mechanisms of S–Fe–P in surface sediments under the stresses of high salinity and heavy metals in coastal rivers

Journal of Soils and Sediments - The aim of the study was to (1) investigate the distributions of sulfur (S), iron (Fe), and phosphorus (P) in coastal surface sediments under the stresses of high...     

Contamination by PAHs,PCBs, PCPs and heavy metals in the mecoácfin lake estuarine water and sediments after oil spilling

Intention, Goal, Scope, Background  Environmental pollution caused by oil spills is a major ecological problem. Oil contamination in the environment is primarily evaluated by measuring the chemical concentrations of hydrocarbons. The results of chemical analyses are important for estimating water and sediment quality in the risk assessment to the flora and fauna of oil-contaminated sites. In the world there are lake ecosystems under permanent chemical stress due to urbanization and the oil industry. Studies, however, have been generally limited to petroleum compounds and have not considered other pollutants of the site like PCBs, polychlorinated pesticides and heavy metals. Objective  Water and sediment from stations in the Mecoacán Lake in the Mexican State of Tabasco were analyzed for polycy-clic aromatic compounds (PAHs), aliphatic hydrocarbons (AHs), polychlorinated biphenyls (PCBs), polychlorinated pesticides (PCPs) and heavy metals. The objective of this study was to examine the contaminant levels of the samples collected in February 1993 and 1996 after oil spills at the Mecoacán petroleum region. The goals of this study were to reveal the effect of the spills on the distribution of the hydrocarbons and assess the toxi-cological significance of the levels found. In addition, our aim was to examine the distribution of the PAHs in sediments from Mecoacán originated from both pyrolytic and petrogenic sources. Methods  Samples were collected from 19 stations and prepared according to the CARIPOL (Caribbean Pollution) methodology of the United Nations Environmental Programme (1992) of the Great Caribbean Region for hydrocarbons in marine and coastal water, and sediments. The gas-chromatographic and atomic absorption analysis of the samples was performed after sampling. Results and Discussion  Concentrations of PAHs in water ranged from 0.2 to 0.8 μg/l in 1993 and from 0.3 to 2.8 μg/l in 1996. The concentration of the 16 EPA-PAHs varied from 0.1 to 36 mg/kg dry weight in the lake sediment samples collected in 1996, while those of AHs, PCBs and PCPs ranged from 0.1 to 67 mg/kg, 0.1 to 59 μg/kg and 6 to 370 μg/kg, respectively. The most abundant contaminants in water were benz[a]anthracene and pyrene, in 1993 and 1996, respectively; while in sediments collected in 1996: Pyrene, C₂₄, 2-chlorobiphenyl and endrin predominated. Heavy metals (Cu, Pb and Zn) were found at low concentrations. Benzo[a]pyrene was detected in some sediment samples in varying amounts (0.2 to 0.3 mg/kg). Conclusions  The maximum total PAH concentration in sediments was found at sites near the oil fields and the AH concentration near the urban zone. The mayor pollutants in sediments were PAHs and AHs, and taking into regard the detected PAHs near the oil fields, the source was the oil spilling. The mean total PAH value in Mecoacan sediments of 6.4 mg/kg did not exceed the median range effects value (ERM) for total PAHs of 44.8 mg/kg. The measured organochlorine compounds and heavy metals were present in amounts much inferior to the ERM values. This study confirms that contaminants concentration in sediments did not exceed the environmental quality guideline for the 50% probability and no adverse effect can be expected. Recommendation and Outlook  Analysis revealed no indication of a contribution of PAHs, PCBs, PCPs and heavy metals to acute sediment toxicity. The results of this study demonstrate the importance of continuous monitoring of ecosystems exposed to pollution to make pre-spill data available in order to evaluate the real consequence of the spilling and its effect on flora and fauna.     

The effect of sewage‐sludge on the heavy metal content of soils and plant tissue

Abstract

Domestic sewage sludge applied to farm fields at a rate of 44.9 kg/ha in a mixture with lime and sawdust was found to increase the soil levels of cadmium, chromium, copper, lead, mercury, nickel and zinc. The average levels in sludge treated soil were: 0.11, 0.56, 3.59, 2.72, 0.068, 1.49 and 2.57 ppm, respectively. The increases were small and the overall loading factors were well below recommended maximums. The uptake of these heavy metals by grass and legume plants was variable with cadmium, copper and zinc levels being higher in those plants growing in the sludge treated soils but only copper was significantly higher. The heavy metal contents found were all within the levels normally found in grass and legume plants. The higher mean concentration in plants growing on the sludge treated soils were cadmium 0.495; chromium 1.22; copper 12.3; lead 1.54; mercury 0.022; nickel 4.08 and zinc 28.4 ppm.     

Humic matter isolated from soils and water by the XAD‐8 resin and conventional NaOH methods

Abstract

Differences were studied in humic (HA) and fulvic acid (FA) extracted from soils and streams in South Georgia by the Amberlite XAD‐8 resin and conventional NaOH method. Characterization analysis was performed by liquid ¹³C NMR, infrared (IR) spectroscopy, scanning electron microscopy (SEM), and chemical analysis. The NMR spectra indicated that the resin method yielded black water HA and FA with spectroscopic, chemical and elemental characteristics different from those isolated by the conventional NaOH method. Humic acids from both the resin and conventional NaOH methods were composed of aliphatic, aromatics and carboxyl groups, but the “resin”; HA contained more aliphatic groups. These differences were also noticed between the FA fractions obtained by the two methods. The differences corresponded to differences in IR spectra. The IR spectrum of “resin”; FA exhibited only a weak shoulder at 1625/cm for the COO”; stretching vibration, in contrast to that of FA isolated by the conventional NaOH procedure. Apparently, the high aliphatic‐CH₃ group content has blocked the vibration above, as evidenced by methylation of HA. Fulvic acid extracted by the resin method was also higher in total acidity, but considerably lower in N content than FA obtained by the conventional NaOH method. Both methods yielded black water FA which was less aromatic in nature than black water HA, or soil FA.     

Investigating speciation and toxicity of heavy metals in anoxic marine sediments—a case study from a mariculture bay in Southern China

Purpose

The pollution of marine sediments by heavy metals is still a major concern, especially in zones affected by industry or mariculture. Toxicity of sediment heavy metal contents may be assessed using sequential extraction (SE) procedures, minding inherent constraints of such approaches. In this study, we investigated heavy metal speciation and toxicity in anoxic marine sediments in Zhelin Bay, a mariculture bay in Southern China, using an SE and acid volatile sulfur-simultaneously extracted metals (AVS-SEM) approach.

Materials and methods

Speciation of Cd, Cu, Ni, Pb, and Zn were studied by a modified SE of five fractions, adapted to separate organic and sulfidic metal fractions in anoxic sediments: F1 weak acid soluble (readily available), F2 reducible fraction, F3 organic matter-bound fraction, F4 sulfide-bound fraction, and F5 residually bound fraction. Toxicity predictions based on the sum of non-residual (NR) metal fractions from sequential extraction were compared to predictions based on AVS-SEM.

Results and discussion

Results showed that Cd, Ni, and Pb predominantly occurred in the weak acid soluble fraction (F1), residual fraction (F5), and sulfide-bound fraction (F4), respectively; Cu and Zn were mainly obtained in F4 and F5. Based on the distribution of indicator elements for metal fractions, the SEM from AVS extraction included different yields of non-residual and residual fractions besides the sulfidic fraction. Estimates for potential heavy metal toxicity based on NR metals of the SE procedure were thus based on a better-defined speciation compared to the simplistic approach of the AVS-SEM method.

Conclusions

Based on the contents of NR metals and normalizing them by organic matter content, toxic effects are not expected for any of the sampling sites, irrespective of the presence or absence of mariculture. Using Pearson correlation analysis to identify predominant fractions influencing toxicity, we conclude that toxicity of heavy metals in anoxic sediments can be well predicted by their non-residual heavy metal contents.

     

Use of reflectometry for determination of nitrate‐nitrogen in well water

Recurrent monitoring of water wells is necessary to ensure that nitrate‐nitrogen (NO3‐N) concentrations in groundwater do not exceed 10 mg/L, the maximum contaminant level set by the U.S. Environmental Protection Agency. Continuous chemical analysis is often a time consuming and expensive process. A recently developed ‘Reflectoquant Analysis System’, which employs reflectometry techniques, may offer a simple and accurate method for NO3‐N analysis. The objective of this study was to evaluate the ‘Reflectoquant Analysis System’ as an alternative method for determination of NO3‐N in well water. Water samples were collected from 42 wells in Oklahoma. The samples were analyzed using the ‘Reflectoquant Analysis System’, automated cadmium reduction (Griess‐Ilosvay), ion chromatography, and phenoldisulfonic acid procedures. The linear range of the ‘Reflectoquant Analysis System’ is 1.1 to 50.6 mg/L NO3‐N. Samples exceeding this range must be diluted before analysis is performed. Excluding two wells where NO3‐N was >50.6 mg/L, simple correlation was high (r > 0.91) among the four procedures evaluated. In addition, slopes and intercepts from linear regression of NO3‐N among procedures were not significantly different. Population means obtained using the four methods were very similar. For this sample of wells, the ‘Reflectoquant Analysis System’ was precise and provided NO3‐N analysis of water samples equivalent to standard methods. Other advantages of the ‘Reflectoquant Analysis System’ are short analytical times, reduced operator training period, and competitive costs compared to standard methods.