Simple flow-injection system for the simultaneous determination of nitrite and nitrate in water samples*1

Burakham, Rodjana; Oshima, Mitsuko; Grudpan, Kate; Motomizu, Shoji

doi:10.1016/j.talanta.2004.03.059

Cited by 77 publications

(25 citation statements)

References 24 publications

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“…Various studies have been published that use the conversion of NO 3 -into N 2 (Silva et al 2000, Voss et al 1997, NH 4 + (Sigman et al 2000, Slawyk and Raimbault 1995, Thunell et al 2004), or N 2 O (Casciotti et al 2002Kaiser et al 2007;Sigman et al 2001Sigman et al , 2005. As part of a "chemical only" approach, Cd metal reduction to NO 2 -has been adapted from the methodology for colorimetric NO 3 -concentration determination (Burakham et al 2004, Gal et al 2004, Hales et al 2004, Nydahl 1976, Thabano et al 2004). All of these methods have advantages and disadvantages.…”

Section: Introductionmentioning

confidence: 99%

Effect of chloride on the chemical conversion of nitrate to nitrous oxide for δ¹⁵N analysis

Ryabenko

Altabet

Wallace

2009

Limnology & Ocean Methods

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We investigate the influence of chloride concentration on the performance of the chemical reduction method for measurement of the nitrogen isotopic ratio (δ 15 N) in NO 3 -in natural waters (McIlvin and Altabet, 2005). In this method, NO 3 -is first reduced to NO 2 -using activated cadmium metal, with further reduction to N 2 O using sodium azide in an acetic acid buffer. N 2 O is introduced into an isotope ratio mass spectrometer (IRMS) for isotopic measurement. Previously, it was recognized that the presence of halides was necessary for the speed and efficiency of the second step but not thought to be important for the first step. Whereas quantitative Cd reduction of NO 3 -to NO 2 -had been noted for seawater samples, here we report, for freshwater and low-salinity (S < 30) samples, a variable conversion efficiency (both under-and overreduction were observed) and significant variation in δ 15 N determination. Addition of 5 M NaCl to all samples resulted in rapid (<4 h) and quantitative (>99%) reduction of NO 3 -to NO 2 -as well as stable δ 15N values that closely matched expected values for standards (within 0.3‰ of standard value). The positive effect of NaCl is likely due to a decrease in free Cd 2+ produced over the course of the reaction due to formation of CdCl 2 .*Corresponding author: E-mail: eryabenko@ifm-geomar.de AcknowledgmentsThe authors thank Frank Malien, Annette Kock, and Gert Petrick for technical assistance. The work was supported by the DFG-funded "Future Ocean" Excellence Cluster and Sonderforschungsbereich 754 "Climate-Biogeochemistry Interactions in the Tropical Ocean." Limnol. Oceanogr.: Methods 7, 2009, 545-552 © 2009, by the American Society of Limnology and Oceanography, Inc. LIMNOLOGY and OCEANOGRAPHY: METHODSdeveloped by McIlvin and Altabet (2005), which uses azide for quantitative nitrite conversion to N 2 O for the isotopic analysis of seawater and freshwater. The method allows separate analysis of nitrite without interference from the isotopic signature of nitrate and has a standard deviation of less than 0.2‰ for δ 15 N in nitrate samples ranging in concentration from 40 to 0.5 µM. We refer to the McIlvin and Altabet method as MA (2005).For NO 3 -concentration measurements (e.g., by an autoanalyzer), a quantitative (100%) reduction is not necessary, because NO 3 -standards are run under exactly the same conditions as the samples, so that sample concentrations are corrected for any N analysis, on the other hand, a quantitative (100%) reduction of NO 3 -is essential to avoid potentially large and variable isotopic fractionation.Application of the MA (2005) method at IFM-GEOMAR includes analysis of samples collected from the Atlantic and Pacific Oceans and the Baltic Sea covering a wide range in salinity (equivalent to 0-0.5 M NaCl). A salinity effect on NO 3 -reduction yields has been discussed in several articles, which examined the effect of Cd column methods for NO 3 -concentration measurements (Gal et al. 2004, Nydahl 1976. For example, Nydahl (1976) argued: "Conside...

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Section: Introductionmentioning

confidence: 99%

Effect of chloride on the chemical conversion of nitrate to nitrous oxide for δ¹⁵N analysis

Ryabenko

Altabet

Wallace

2009

Limnology & Ocean Methods

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“…An additional human threat posed by the presence of nitrite at high concentration in the blood is its reaction with iron (III) of the haemoglobin, forming methemoglobin, which has no oxygen carrying ability 2 . Many analytical methods have been proposed for the detection of nitrite [2][3][4][5][6][7][8][9][10] . Most of the methods employed for the determination of nitrite are based on the colorimetric determination of nitrite with diazocoupling reaction.…”

Section: Introductionmentioning

confidence: 99%

Detection of nitrite by flow injection analysis using a novel paired emitter-detector diode (PEDD) as a photometric detector

et al. 2007

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An inexpensive flow injection analysis system for determining low concentration levels of nitrite employing the Griess reagent spectrophotometric method is reported. The novel photometric detector applied within this manifold is a highly sensitive, low cost, miniaturized light emitting diode (LED) based flow detector. This colorimetric detector employs two LEDs, operating one as a light source and the other as a light detector. The emitter LED is forward biased and the detector reverse biased. The emitter and detector LED had a λ max of 530 nm and 623 nm respectively. The emission spectrum of the emitter LED efficiently overlapped with the absorbance spectrum of 9 µM NO 2 and Griess reagent complex. A simple timer circuit measures the time taken for the photocurrent generated by the emitter LED to discharge the detector LED from 5 V (logic 1) to 1.7 V (logic 0). The Griess reagent method employed for nitrite determination is based on the formation of an azo dye, the intensity of which is directly related to nitrite concentration. The linear range, reproducibility and limit of detection were investigated. Detection limits in the nanomolar range were achieved using the Paired Emitter-Detector Diode (PEDD) flow analysis device. For a comparative study the linear range and limit of detection were also investigated using a platewell reader. Higher sensitivity and improved precision were obtained from the PEDD compared to the commercially available plate well reader.

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“…Flow systems for the water quality testing have been reported in several papers (Hirata et al, 2003, Steimle et al, 2002, Greenway et al, 1999, Moorcroft et al, 2001, Burakham et al, 2004 to solve these problems. In particular, micro-systems for chemical analysis, i.e., micro total analysis systems (μ-TAS), have attracted attention as a new approach (Manz, et al, 1990, Cefai, et al, 1994, Verpoorte et al, 1994.…”

Section: Introductionmentioning

confidence: 99%

Fundamental study on compact absorptiometer for water quality testing

Matsuzawa

Asano

Morita

2015

JAMDSM

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A compact absorptiometer for water quality testing that does not need a special technique to take measurements was studied where the absorbance of a sample solution could be stably measured without decreasing the sensitivity over time. Three types of devices were developed, namely, horizontal straight-line type, vertical straight-line type, and multiple reflection type, that consisted of a light emitting diode (LED), a photodiode (PD), and a glass capillary used as a sample cell. The results from our experiments conducted to detect the nitrite nitrogen in water, which is a factor in water pollution, were used to evaluate how these three devices perform. The shapes of the liquid surfaces at the end of the capillaries in the horizontal and vertical straight-line types, which had the LED, PD, and the glass capillary in line horizontally and vertically, respectively, significantly influenced the output voltage of the PD and this output significantly changed over time, so it was difficult to precisely measure the absorbance. The change in the shape of the liquid surface at the end of the capillary was particularly considerable in the horizontal straight-line type. On the other hand, in the multiple reflection type, which had reflective plates surrounding the glass capillary, the absorbance was measured quite stably because the light emitted by the LED did not transmit through the liquid surface at the end of the capillary and the output voltage of the PD was uninfluenced by the change in the shape of the liquid surface. Additionally, controlling the sensitivity of the absorbance was possible by adjusting the length of the reflective plates, i.e., adjusting the light path. The sample solution in this device did not come into direct contact with the reflective plate, so the device can suppress the decrease in the sensitivity caused by materials becoming directly attached to the reflection plate. The compact multiple reflection type device that was developed could be used in a manually operated portable absorptiometer and also in an automated water quality analysis system that incorporates mixing and flow devices.

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Simple flow-injection system for the simultaneous determination of nitrite and nitrate in water samples*1

Cited by 77 publications

References 24 publications

Effect of chloride on the chemical conversion of nitrate to nitrous oxide for δ¹⁵N analysis

Effect of chloride on the chemical conversion of nitrate to nitrous oxide for δ¹⁵N analysis

Detection of nitrite by flow injection analysis using a novel paired emitter-detector diode (PEDD) as a photometric detector

Fundamental study on compact absorptiometer for water quality testing

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Simple flow-injection system for the simultaneous determination of nitrite and nitrate in water samples*1

Cited by 77 publications

References 24 publications

Effect of chloride on the chemical conversion of nitrate to nitrous oxide for δ15N analysis

Effect of chloride on the chemical conversion of nitrate to nitrous oxide for δ15N analysis

Detection of nitrite by flow injection analysis using a novel paired emitter-detector diode (PEDD) as a photometric detector

Fundamental study on compact absorptiometer for water quality testing

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Product

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Effect of chloride on the chemical conversion of nitrate to nitrous oxide for δ¹⁵N analysis

Effect of chloride on the chemical conversion of nitrate to nitrous oxide for δ¹⁵N analysis