Olasehinde Emmanuel F, Makino Shinya, Kondo Hiroaki, Takeda Kazuhiko, Sakugawa Hiroshi
Graduate School of Biosphere Science, Department of Environmental Dynamics and Management, Hiroshima University, 1-7-1 Kagamiyama, Higashi Hiroshima 739-8521, Japan.
Anal Chim Acta. 2008 Oct 10;627(2):270-6. doi: 10.1016/j.aca.2008.08.026. Epub 2008 Aug 28.
A simple and sensitive method for the determination of nanomolar levels of hydrogen peroxide (H(2)O(2)) in seawater has been developed and validated. This method is based on the reduction of H(2)O(2) by ferrous iron in acid solution to yield hydroxyl radical (OH) which reacts with benzene to produce phenol. Phenol is separated from the reaction mixture by reversed phase high performance liquid chromatography and its fluorescence intensity signals were measured at excitation and emission of 270 and 298nm, respectively. Under optimum conditions, the calibration curve exhibited linearity in the range of (0-50)x10(3)nmolL(-1) H(2)O(2). The relative standard deviations for five replicate measurements of 500 and 50nmolL(-1) H(2)O(2) are 1.9 and 2.4%, respectively. The detection limit for H(2)O(2), defined as three times the standard deviation of the lowest standard solution (5nmolL(-1) H(2)O(2)) in seawater is 4nmolL(-1). Interference of nitrite ion (NO(2)(-)) on the fluorescence intensity of phenol was also investigated. The result indicated that the addition of 10micromolL(-1) NO(2)(-) to seawater samples showed no significant interference, although, the addition of 50micromolL(-1) NO(2)(-) to the seawater samples decreases the fluorescence intensity signals of phenol by almost 40%. Intercomparison of this method with well-accepted (p-hydroxyphenyl) acetic acid (POHPAA)-FIA method shows excellent agreement. The proposed method has been applied on-board analysis of H(2)O(2) in Seto Inland seawater samples.
已开发并验证了一种用于测定海水中纳摩尔水平过氧化氢（H₂O₂）的简单灵敏方法。该方法基于酸性溶液中二价铁将H₂O₂还原生成羟基自由基（OH），后者与苯反应生成苯酚。通过反相高效液相色谱法将苯酚从反应混合物中分离出来，并分别在激发波长270nm和发射波长298nm处测量其荧光强度信号。在最佳条件下，校准曲线在（0 - 50）×10³nmol·L⁻¹ H₂O₂范围内呈线性。500和50nmol·L⁻¹ H₂O₂五次重复测量的相对标准偏差分别为1.9%和2.4%。海水中H₂O₂的检测限定义为最低标准溶液（5nmol·L⁻¹ H₂O₂）标准偏差的三倍，为4nmol·L⁻¹。还研究了亚硝酸根离子（NO₂⁻）对苯酚荧光强度的干扰。结果表明，向海水样品中添加10μmol·L⁻¹ NO₂⁻没有显著干扰，不过，向海水样品中添加50μmol·L⁻¹ NO₂⁻会使苯酚的荧光强度信号降低近40%。将该方法与公认的（对羟基苯基）乙酸（POHPAA）-流动注射分析法（FIA）进行比对，结果显示两者具有良好的一致性。所提出的方法已应用于濑户内海海水样品中H₂O₂的船上分析。
