کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4433094 1619931 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
An evaluation of freezing as a preservation technique for analyzing dissolved organic C, N and P in surface water samples
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
پیش نمایش صفحه اول مقاله
An evaluation of freezing as a preservation technique for analyzing dissolved organic C, N and P in surface water samples
چکیده انگلیسی

ABSTRACTTechniques for preserving surface water samples are recently in demand because of the increased interest in quantifying dissolved organic matter (DOM) in surface waters and the frequent collection of samples in remote locations. Freezing is a common technique employed by many researchers for preserving surface water samples; however, there has been little evaluation of the effects of freezing on DOM concentrations. Ten streams were sampled in southeast Alaska with a range of dissolved organic carbon (DOC) concentrations (1.5 to 39 mg C L− 1) to evaluate the influence of freezing (flash and standard freeze) and filter pore size (0.2 and 0.7 μm nominal pore size) on dissolved organic C, N and P concentrations. We report a significant decrease in DOC (p < 0.005) and total dissolved P (p < 0.005) concentrations when streamwater samples were frozen, whereas concentrations of dissolved organic N did not significantly decrease after freezing (p = 0.06). We further show that when surface water samples were frozen, there was a decrease in the specific ultraviolet absorbance (SUVA) of DOC that is particularly evident with high concentrations of DOC. This finding suggests that spectroscopic properties of DOC have the potential to be used as indicators of whether surface water samples can be frozen. Our results lead us to recommend that surface water samples with high DOC concentrations (> 5 mg C L− 1) and/or samples with high SUVA values (> 3.5–4 L mg-C− 1 m− 1) should be analyzed immediately and not frozen.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Science of The Total Environment - Volume 392, Issues 2–3, 25 March 2008, Pages 305–312
نویسندگان
, , ,