SPECIATION OF DISSOLVED COPPER AND NICKEL IN SOUTH SAN-FRANCISCO BAY - A MULTIMETHOD APPROACH
SPECIATION OF DISSOLVED COPPER AND NICKEL IN SOUTH SAN-FRANCISCO BAY - A MULTIMETHOD APPROACH
复制标题
DOI：
10.1016/0003-2670(94)85061-5
复制
发表时间：
1994-01-10
影响因子：
6.2
通讯作者：
BRULAND, KW
中科院分区：
文献类型：
--
作者：
DONAT, JR;LAO, KA;BRULAND, KW
采用多种方法对南旧金山湾溶解的铜和镍的化学形态进行了研究。采用竞争配基平衡-阴极溶出伏安法[CLE-CSV]、汞膜旋转玻碳圆盘电极差分脉冲阳极溶出伏安法[DPASV(TMF-RGCDE)]、悬汞电极DPASV[DPASV(HMDE)]和螯合树脂柱分配-石墨炉原子吸收光谱法[CRCP-GFAAS]等4种不同的分析方法测定了溶解铜的形态。用CLE-CSV和CRCP-GFAAS测定了溶解镍的形态。所采用的每一种方法都对溶解的铜和镍的化学形态提供了有用的见解。CLE-CSV最好地表征了所检测的两种有机络合铜配体中较强的(但不是占优势的)，而DPASV(TMF-RGCDE)提供了最真实的无机铜的测量，因此，最好地表征了对溶解铜形态影响最大的较弱的有机络合铜配体。这些方法提供了互补的结果，它们可以结合在一起，提供对铜的化学形态的更完整的了解。DPASV(HMDE)和CRCP-GFAAS都提供了对不稳定铜的操作测量，除了无机铜物种外，还包括一些不稳定的有机络合物。CLE-CSV和CRCP-GFAAS对镍的形态形成都产生了类似的结果，表明存在一类非常强的镍配位配体。南旧金山湾的溶解铜主要以有机络合物的形式存在(80-92%)。约27%的溶解铜与较强的(L(1)；[CuL(1)]约13 nm，logK‘(CuL1)>；13.5)络合，而与较弱的配体L(2)配位的铜占总溶解铜的比例最大(52-65%；[CuL(2)]约20-30 nm；logK’(CuL2)=9.0-9.6)。总溶解镍的1/3~1/2被一类极强的有机配体络合([nil]约17-28 nM；logK‘(Nil)>；17)；其余的总溶解镍以无机或不稳定的形式存在。
A multi-method approach was used to investigate the chemical speciation of dissolved copper and nickel in South San Francisco Bay. Dissolved copper speciation was determined by four different analytical approaches: competitive ligand equilibration-cathodic stripping voltammetry [CLE-CSV], differential pulse anodic stripping voltammetry using a thin mercury film rotating glassy carbon disk electrode [DPASV(TMF-RGCDE)], DPASV using a hanging mercury drop electrode [DPASV(HMDE)], and chelating resin column partitioning-graphite furnace atomic absorption spectrometry [CRCP-GFAAS]. Dissolved nickel speciation was determined by CLE-CSV and CRCP-GFAAS. Each of the methods employed provided useful insight into the chemical speciation of dissolved copper and nickel. CLE-CSV provided the best characterization of the stronger (but less predominant) of the two organic copper-complexing ligands detected, while DPASV(TMF-RGCDE) provided the truest measurement of inorganic copper, and therefore, the best characterization of the weaker organic copper-complexing ligand which exerted the strongest influence on dissolved copper speciation. These methods provide complementary results which can be combined to provide a more complete understanding of the chemical speciation of copper. DPASV(HMDE) and CRCP-GFAAS both provide an operational measurement of labile copper which includes some fraction of labile organic complexes in addition to inorganic copper species. CLE-CSV and CRCP-GFAAS both yielded similar results for nicker speciation indicating the presence of a single class of extremely strong nickel-complexing ligands. The dissolved copper in South San Francisco Bay is found to exist predominantly as organic complexes (80-92%). About 27% of dissolved copper was complexed with the stronger (L(1); [CuL(1)]approximate to 13 nM, log K'(CuL1)>13.5) of the copper-complexing ligands detected, while copper complexed with the weaker ligand L(2) comprised the greatest fraction of total dissolved copper species (52-65%; [CuL(2)]approximate to 20-30 nM; log K'(CuL2)=9.0-9.6). A third to a half of total dissolved nicker was complexed by one, extremely strong class of organic ligands ([NiL]approximate to 17-28 nM; log K'(NiL)>17); the remaining total dissolved nickel existed as inorganic or labile forms.