scholarly journals Effects of chloride, calcium, and dissolved organic carbon on silver toxicity: Comparison between rainbow trout and fathead minnows

1999 ◽  
Vol 18 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Nicolas R. Bury ◽  
Fernando Galvez ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Fathead Minnows ◽  
Silver Toxicity

Bioavailability and acute toxicity of copper to rainbow trout (Oncorhynchus mykiss) in the presence of organic acids simulating natural dissolved organic carbon

1999 ◽  
Vol 56 (8) ◽  
pp. 1471-1483 ◽  
Author(s):  
J CA Marr ◽  
J Lipton ◽  
D Cacela ◽  
J A Hansen ◽  
J S Meyer ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Organic Carbon ◽  
Acute Toxicity ◽  
Dissolved Organic Carbon ◽  
Oncorhynchus Mykiss ◽  
Failure Time ◽  
Life Stage ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Organic Complexes ◽  
Inorganic Species

Copper bioavailability and toxicity to early life stage rainbow trout (Oncorhynchus mykiss) were evaluated by laboratory toxicity testing performed using organic acid mixtures. Geochemical modeling was used to design exposure solutions that simulate dissolved organic carbon (DOC) of a natural aquatic system and to determine the fractions of total Cu present as inorganic species (e.g., Cu2+) and as individual Cu-organic complexes. Failure time modeling indicated that mortality was best predicted by a combination of total inorganic Cu and distinct Cu-organic complexes. The Cu-organic complexes that contributed to toxicity are characterized as low-affinity Cu-ligands, and our results support the hypothesis that Cu toxicity in nature is a function of the binding characteristics of individual ligands. Estimates of time-independent median lethal concentration thresholds determined at widely varying equivalent concentrations of DOC (0-16 mg/L) were constant (7.9-8.6 µg Cu/L) when modeled using the sum of inorganic Cu and Cu bound to the two low-affinity ligands as predictors of toxicity. Our results indicate that Cu bound to organic complexes may be available to fish and that acute toxicity of Cu is determined by the binding affinities of specific DOC components relative to Cu-binding affinity of fish gill.

CHARACTERISATION OF DISSOLVED ORGANIC CARBON (DOC) LEACHED FROM LEAVES IN WATER

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Markus Heryanto Langsa
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Total Organic Carbon ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Pyrolysis Gas Chromatography ◽  
Chromatography Mass Spectrometry ◽  
Pinus Radiate

<p>Penelitian ini bertujuan untuk menentukan senyawa organik khususnya organic karbon terlarut (DOC) dari dua spesies daun tumbuhan (<em>wandoo eucalyptus </em>and <em>pinus radiate, conifer</em>) yang larut dalam air selama periode 5 bulan leaching eksperimen. Kecepatan melarutnya senyawa organic ditentukan secara kuantitatif dan kualitatif menggunakan kombinasi dari beberapa teknik diantaranya Total Organic Carbon (TOC) analyser, Ultraviolet-Visible (UV-VIS) spektrokopi dan pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS).</p><p>Hasil analisis DOC dan UV menunjukkan peningkatan yang tajam dari kelarutan senyawa organic di awal periode pengamatan yang selanjutnya berkurang seiring dengan waktu secara eksponensial. Jumlah relatif senyawa organic yang terlarut tergantung pada luas permukaan, aktifitas mikrobiologi dan jenis sampel tumbuhan (segar atau kering) yang digunakan. Fluktuasi profil DOC dan UV<sub>254</sub> disebabkan oleh aktifitas mikrobiologi. Diperoleh bahwa daun kering lebih mudah terdegradasi menghasilkan senyawa organic dalam air dibandingkan dengan daun segar. Hasil pyrolysis secara umum menunjukkan bahwa senyawa hidrokarbon aromatic dan fenol (dan turunannya) lebih banyak ditemukan pada residue sampel setelah proses leaching kemungkinan karena adanya senyawa lignin atau aktifitas humifikasi mikrobiologi membuktikan bahwa senyawa-senyawa tersebut merupakan komponen penting dalam proses karakterisasi DOC.</p>

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