ENVIRONMENTAL CHEMISTRY

32 10 2013 10 ENVIRONMENTAL CHEMISTRY Vol 32 No 10 October 2013 DOI 10 7524 /j issn 0254-6108 2013 10 019 * 1 2 1** 1 1 1 1 264003 2 100049 0 8 mm 90 cm 3 5 min 11% SA 45 g L - 1 N- 1- - NED 2HCl 50 mg L - 1 10 1000 μg L - 1 4 14 μg L - 1 1 2% 105 4% 122 1% 1 2 3-4 2-3 5 3 6 7-8 9-11 12 Sequential injection analysis SIA 13 1 1 1 PreFluidYZ15 PMF-L6 DH-T-E DIFF2 Cuvette PLC Panasonic Panasonic LED PTFE H 3 PO 4 NaNO 2 SA N- 1- - NED 2HCl 18 2 MΩ cm 1 2 500 ml 250 ml 55 ml 22 5 g SA 0 025 g 2012 12 10 * ** E-mail lxchen@ yic ac cn

10 1951 NED 2HCl 500 ml 2 5 1 0 μg L - 1 1 g L - 1 NaNO 2 60 1 h 2 465 g 500 ml 1 ml 2 5 2 2 1000 μg L - 1 1 ml 1000 ml 1 3 3 4 1 4 1 NO - 2 540 nm 14 1 SIA V1 V2 V3 V4 V5 P1 P2 V6 D PV L S1 1 0 μg L - 1 S2 2 1000 μg L - 1 CA CW WS W1 W2 DW Fig 1 SIA diagram of on-line nitrite determination 1 5 PLC 1 V5 P2 2 1 s V5 30 s P2 40 s 4 2 P1 40 s P2 40 s 3 5 min 3 P1 40 s P2 40 s 3 5 min 4 2 2 1 2 1 1 PTFE

1952 32 1 25 1 00 0 80 mm PTFE 0 80 mm PTFE 2 1 2 15 90 cm PTFE 0 80 mm 2 1 3 2 3 min 3 5 min 2 2 SA NED 2HCl 500 μg L - 1 2 2 1 100 ml 5 6 7 8 9 10 11 12 ml 3 11 ml 11 11 ml 11 ml 11% Fig 2 2 A Effect of reaction time on indicator absorbance 3 A Fig 3 Effect of phosphoric acid content in chromogenic regent on indicator absorbance 2 2 2 SA SA SA 4 SA SA 50 g L - 1 SA 45 g L - 1 2 2 3 NED 2HCl NED 2HCl NED 2HCl NED 2HCl 5 NED 2HCl 50 mg L - 1 50 mg L - 1 50 mg L - 1 NED 2HCl 50 mg L - 1 2 3 500 μg L - 1 NO - 2 ± 5% 3000 Na + K + Cl - 1000 Mg 2 + Ca 2 + SO 2-4 NO - 3 500 Cu 2 + Fe 3 + SCN - I - C 5 H 7 O 5 COO -

10 1953 100 Pb 2 + CO 2-3 ph 11 4 SA A Fig 4 Effect of concentration of sulfanilamide on indicator absorbance 5 NED 2HCl A Fig 5 Effect of concentration of NED 2HCl on indicator absorbance 2 4 0 10 40 50 100 200 400 600 800 1000 μg L - 1 A Y μg L - 1 X 10 1000 μg L - 1 Y = 0 8917X + 0 0009 R 2 = 0 9999 500 μg L - 1 10 1 2% 21 4 14 μg L - 1 2 5 GB7493 87 1 105 4% 122 1% Table 1 1 / μg L - 1 n = 8 Results and recovery for water samples detection n = 8 / μg L - 1 / / μg L - 1 μg L - 1 /% 1 153 0 154 8 2 153 7 151 2 3 124 6 126 3 150 0 320 1 167 1 111 4 200 0 387 1 234 1 117 1 80 0 251 4 97 7 122 1 180 0 354 7 201 0 116 7 150 0 288 0 163 4 108 9 180 0 314 3 189 7 105 4 2 6 1 h 1 6 465 475 μg L - 1 9 00 22 00

1954 32 Fig 6 6 On-line real-time determination of nitrite in water samples 3 1 PLC 2 0 8 mm 90 cm 3 5 min 11% SA 45 g L - 1 NED 2HCl 50 mg L - 1 3 10 1000 μg L - 1 RSD = 1 2% 4 14 μg L - 1 105 4% 122 1% 1 Pasquali C E Gallego-Pico A Fernandez Hernando P et al Two rapid and sensitive automated methods for the determination of nitrite and nitrate in soil samples J Microchemical Journal 2010 94 1 78-82 2 J 2005 24 6 733-734 3 Akyuz M Ata S Determination of low level nitrite and nitrate in biological food and environmental samples by gas chromatography-mass spectrometry and liquid chromatography with fluorescence detection J Talanta 2009 79 3 900-904 4 Wang X Adams E Van Schepdael A A fast and sensitive method for the determination of nitrite in human plasma by capillary electrophoresis with fluorescence detection J Talanta 2012 97 5 142-144 5 Ito K Nomura R Fujii T et al Determination of nitrite nitrate bromide and iodide in seawater by ion chromatography with UV detection using dilauryldimethylammonium-coated monolithic ODS columns and sodium chloride as an eluent J Analytical and Bioanalytiacl Chemistry 2012 404 8 2513-2517 6 Hord N G Tang Y P Bryan N S Food sources of nitrates and nitrites The physiologic context for potential health benefits J American Journal of Clinical Nutrition 2009 90 1 1-10 7 Veena K Narayana B Spectrophotometric determination of nitrite using new coupling agents J Indian Journal of Chemical Technology 2009 16 1 89-92 8 - J Chinese Journal of Spectroscopy Laboratory 2012 29 3 1518-1522 9 Idris A M An overview of the generations and recent versions of flow injection techniques J Critical Reviews in Analytical Chemistry 2010 40 3 150-158 10 Grigoryan A A Cornish S L Buziak B et al Competitive oxidation of volatile fatty acids by sulfate-and nitrate-reducing bacteria from an oil field in Argentina J Applied and Environmental Microbiology 2008 749 14 4324-4335 11 - J 2003 22 3 278-283 12 dos Santos A C V Masini J C Sequential injection analysis SIA Twenty years in a Brazilian perspective J Quimica Nova 2010 33 9 1949-1956 13 Senra-Ferreiro S Pena-Pereira F Lavilla I et al Griess micro-assay for the determination of nitrite by combining fibre optics-based

10 1955 cuvetteless UV Vis micro-spectrophotometry with liquid-phase microextraction J Analytica Chimica Acta 2010 668 2 195-200 14 Tsikas D Analysis of nitrite and nitrate in biological fluids by assays based on the Griess reaction Appraisal of the Griess reaction in the L-arginine /nitric oxide area of research J Journal of Chromatography B - Analytical Technolgies in the Biomedical and life Science 2007 851 1-2 51-70 15 M 1999 35-36 Development of a sequential injection analyzer and its application in the determination of nitrite in environmental water samples LYU Ying 1 2 CHEN Lingxin 1* SUN Xiyan 1 FU Longwen 1 FENG Weiwei 1 1 Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone Research Chinese Academy of Sciences Yantai 264003 China 2 University of Chinese Academy of Sciences Beijing 100049 China ABSTRACT An automatic instrument based on sequential injection analysis technique and Griess reagent colorimetric method was developed and applied to the determination of nitrite in environmental water samples The instrument's physical parameters were optimized as follow the inner diameter of pipe 0 8 mm length of sample loop 90 cm reaction time 3 5 min The optimized composition of the colorimetric neagents were that the volume fraction of phosphoric acid was 11% and concentrations of sulfonamides SA and N- 1-naphthyl -ethylenediamine hydrochloride salt NED 2HCl were 45 g L - 1 and 50 mg L - 1 respectively Under the optimized conditions a linear rang of 10 1000 μg L -1 detection limit of 4 14 μg L -1 relative standard deviation of 1 2% and recovery rate of 105 4% 122 1% were achieved The instrument is simple automatic reliable and therefore applicable for on-line and real-time determination of nitrite in complex water samples Keywords sequential injection analysis nitrite spectrophotometry online monitoring water quality analysis