,,, (, 266100) 摘要 : 传统分光光度法测定硝酸盐和亚硝酸盐含量时检测限较高, 无法测定部分海洋表层及寡营养盐海域低含量的硝酸盐和亚硝酸盐浓度, 急需采用一种新的测定低浓度硝酸盐和亚硝酸盐的方法 化学发光法用于测定水体中硝酸盐和亚硝酸盐含量, 具有灵敏度高 检测限低 样品用量少, 不受悬浮颗粒物 有色物质影响及样品批量测定等优点 本文通过探索载气流速 反应温度 还原剂浓度及酸度等关键因素对反应信号值的影响, 在实验室建立了用化学发光测定天然水体中硝酸盐和亚硝酸盐含量的方法, 并确定了最佳实验条件 该方法测定水体中硝酸盐和亚硝酸盐浓度的检测限为 10 nmol/l, 当样品浓度为 200 400 nmol/l 时, 精密度分别为 5% 和 3% 关键词 : 硝酸盐 ; 亚硝酸盐 ; 化学发光法 ; 低浓度 ; 天然水体中图分类号 : P734.4+4 文献标识码 : A 文章编号 : 1000-3096(2011)05-0095-05,, NO 3 NO 2 NO 2 NO 3 NO 2 100 nmol/l 20 nmol/l [1], NO 3 NO 2,, NO 3 NO 2 60 110 nmol/l, [2-3] 1970 Fontijin [4] NO; 1980 Cox [5] ; 1982 Garside [6] NO 3 NO 2 ; 1989 Braman [7], NO - 3 (NH 4 ) 2 Fe(SO 4 ) 2 -(NH 4 ) 2 MoO 4 [5-6] VCl [7] 3 TiCl [8] 3, (85 95 ), ;, [7], VCl 3 [5-7], VCl 3,,, 1 试剂与方法 1.1 仪器和试剂 ( Teledyne ); N2000 ( ); (99.9999%); (0.45μm); VCl 3 ( Alfa Aescar ); HCl( ); NaOH ( ) 1.2 实验原理 (ph 1); NO 2 NO 3,, NaI [3,5,6] Vc-HAc [9] NO 3 VCl 3 NO 2, NO 2 VCl 3 (NH 4 ) 2 Fe(SO 4 ) 2 -(NH 4 ) 2 MoO 4 : 2009-06-20; : 2009-09-30 : (40876054, 40730847); (108081); (2006CB4006) : (1984-),,,,, : 15140545384, E-mail: wyzplforever@163.com Marine Sciences / Vol. 35, No. 5 / 2011 95
: NO, NO NO * 2, NO * 2,, NO [5], * 3 2 2 NO+O NO +O * 2 2 NO NO + hγ 1.3 实验方法 10 ml VCl 3,,, NO ( ) NaOH ( ) (0.45 μm ), O 3,, ( 1) 2 结果与讨论 2.1 最佳实验条件探索 2.1.1 80 200 13 ( ) ( 2), 120,, 2.94%, 150 2.1.2 VCl 3, 0.01 ~0.175 mol/l, 12 ( ) VCl 3 ( 3) VCl 3, 1 Fig. 1 Apparatus arrangement 96 / 2011 / 35 / 5 VCl 3 0.03 mol/l VCl 3, VCl 3 0.03 mol/l, 2 ( 3 ) Fig.2 The effect of temperature on nitrate response signals : 10 ml 0.1 mol/l VCl 3 ; 1 mol/l HCl; 480 ml/min; 4 μmol/l; 200 μl Experiment conditions: 10 ml of 0.1mol/L VCl 3, 1 mol/l HCl; flow rate 480 ml/min; nitrate concentration, 4 μmol/l; inject volume, 200 μl
3 VCl 3 ( 3 ) Fig. 3 The effect of VCl 3 concentration on nitrate response signals : 10 ml VCl 3 ; 1 mol/l HCl; 150 ; 480 ml/min; 4 μmol/l; 200 μl Experiment condition: 10 ml VCl 3, 1 mol/l HCl; temperatue 150 ; flow rate 480 ml/min; nitrate concentration, 4 μmol/l; inject volume, 200 μl, VCl 3 0.1 mol/l 2.1.3 HCl HCl, 12 ( )( 4),, HCl, HCl 0.5 mol/l,, HCl 2 mol/l 2.1.4 7 ( ), ( 5),, 480 ml/min, 480 ml/min,, 0.1 mol/l VCl 3 2 mol/l HCl 150 480 ml/min 2.2 化学发光法测定硝酸盐和亚硝酸盐含量的盐效应 8,, 97% 103% ( 1), 2.3 化学发光法测定硝酸盐和亚硝酸盐含量的回收率 12, ( 2) 88.9% 111.1%, 95% 105% 4 HCl ( 3 ) Fig. 4 The effect of the HCl concentration on nitrate response signals : 10 ml 0.1 mol/l VCl 3 ; 150 ; 480 ml/min; 4 μmol/l; 200 μl Experiment condition: 10 ml of 0.1 mol/l VCl 3 ; temperatue 150 ; flow rate, 480 ml/min; nitrate concentration, 4 μmol/l; inject volume, 200 μl 5 ( 3 ) Fig. 5 The effect of flow rate on nitrate response signals : 10 ml 0.1 mol/l VCl 3 ; 1 mol/l HCl; 150 ; 4 μmol/l; 200 μl Experiment condition: 10 ml of 0.1 mol/l VCl 3, 1 mol/l HCl; temperatue 150 ; nitrate concentration, 4 μmol/l; inject volume, 200 μl Marine Sciences / Vol. 35, No. 5 / 2011 97
表 1 盐度对化学发光法的影响 Tab. 1 The Effect of salt concentration on the measured values (μmol/l) (μmol/l ) (%) 34.0 20.0 20.0 100.2 22.7 13.3 13.7 102.6 17.0 10.0 10.3 102.6 11.3 6.7 6.6 99.1 8.5 5.0 4.9 97.9 6.8 4.0 3.9 97.6 4.3 2.5 2.5 100.4 3.1 1.8 1.8 101.2 表 2 天然水体加标实验 Tab. 2 Natural waters spiked with stardard materials (μmol/l) (μmol/l) (%) () 3.23 1.92 100.7 8.12 3.70 103.6 8.84 3.70 107.0 0.15 0.095 101.1 0.25 0.095 103.5 0.19 0.095 111.1 () 12.7 4.55 102.8 18.9 6.52 99.2 9.01 3.70 100.6 (HgCl 2 ) 4.13 2.38 100.3 6.21 2.86 103.3 10.7 2.38 90.6 5, 3, 10 nmol/l; 200 nmol/l 400 nmol/l, 5% 3% 2.5 方法优缺点,,,, NO, NO 3 NO 2, [4-7],, 3 min, 3 化学发光法与传统分光光度法结果对比 50 ( 6) 3.65%,, 2.4 化学发光法测定硝酸盐和亚硝酸盐含量的检测限 精密度 NO, 200 µl 1 ml, 3 表 3 工作曲线 Tab. 3 Calibration curves Sd R 2 200 µl y =620.36x 11243 ±16.1 0.99 0.9999 1 ml y =3134x+54330 ±124.5 0.99 0.9999 : x (nmol/l); y ; Sd 6 Fig. 6 Correlation between the chemiluminescent technique and the conventional spectrophotometric method 4 小结 (1),,, : VCl 3 0.1 98 / 2011 / 35 / 5
mol/l HCl 2 mol/l 150 480 ml/min (2) 95% 105%, 10 nmol/l, 200 nmol/l 400 nmol/l, 5% 3% (3), : [1] Grasshoff K, Kremling K, Ehrhardt M. Methods of Seawater Analysis (Third edition)[m]. Weinheim: Verlag Chemie, 1999. [2] Masserini R T, Fanning K A. A sensor package for the simultaneous determination of nanomolar concentrations of nitrite, nitrate, and ammonia in seawater by fluorescence detection[j]. Marine Chemistry, 2000, 68: 323-333. [3],,,. [J]., 2007, 25(2): 36-45. [4] Fontijin A, Sabadell A J, Ronco R J. Homogeneous chemiluminescent measurement of nitric oxide with ozone[j]. Analytical Chemistry, 1970, 42(6): 575-579. [5] Cox R D. Determination of nitrate and nitrite at the parts per billion level by chemiluminescence[j]. Anal Chem, 1980, 52: 332-335. [6] Garside C. A chemiluminescent technique for the determination of nanomolar concentration of nitrate and nitrite in seawater[j]. Marine Chemistry, 1982, 11: 59-167. [7] Braman R S, Hendrix S A. Nanogram nitrite and nitrate determination in environmental and biological materials by vanadium(iii) Reduction with chemiluminescence detection[j]. Anal Chem, 1989, 61: 2715-2718. [8] Zafiriou O C, Ball L A, Hanley Q. Trace nitrite in oxic water[j]. Deep-Sea Research, 1992, 39: 1329-1347. [9] Nagababu E, Rifkind J M. Measurement of plasma nitrite by chemiluminescence without interference of S-,N-nitroso and nitrated species[j]. Free Radical Biology & Medicine, 2007, 42: 1146-1154. [10] Dore J E, Karl D M. Nitrite distributions and dynamics at Station ALOHA[J]. Deep-Sea Research II, 1996, 43(2-3): 385-402. Chemiluminescent measurement of low concentrations of nitrate and nitrite WANG Yan, LIU Su-mei, REN Jing-ling, ZHANG Gui-ling (Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education, Ocean University of China, Qingdao 266100, China) Received: Jun., 20, 2009 Key words: nitrate; nitrite; low concentration; natural water; chemiluminescence Abstract: Chemiluminescent technique was applied for the determination of nanomolar quantities of nitrate and nitrite. Suspended particles and chromaphores did not interfere and were hence not necessary to be removed. The optimal experimental conditions with detection limit of 10 nmol/l were set up in the laboratory. The relative standard deviation was 5% at the 200 nmol/l level and 3% at the 400 nmol/l level. At wider detected range, greater accuracy and precision were obtained for this technique comparing to the conventional spectrophotometric methods. Consistent results were obtained when the concentrations of nitrate and nitrite in seawater and river water samples were measured using these two methods. ( 本文编辑 : 康亦兼 ) Marine Sciences / Vol. 35, No. 5 / 2011 99