? asked in 科學化學 · 1 decade ago


When applying the two means t-test (Miller & Miller, 1993) and comparing the t statistics with the critical value for 95% confidence and 6_ of freedom that is 2.447, it was found that the mean results for Cu leaching from the two methods were significantly different.

This indicated that organic matters (protein amino acids) had important role in controlling the release of Cu.

H2O2 could dissociate to hydroxyl radical (OH_) that could attack proteins, carbohydrates and polyunsaturated fatty acids present in the samples.

Hence, it improved the efficiency of the Cu extraction (Azouzi et al., 1998; Goodman, Green, & McPhail, 1984).

On the other hand, H2O2 was an insignificant variable for Cd and Zn leaching from both fish and mussel samples.

Regarding to above discussion, the concentrations of the used acids did not affect the leaching efficiency.

A mild and appropriate condition of leaching solution should be 1:1:1 HNO3(0.5 M):HCl(0.5 M):H2O2(0.5 M).

This acid mixture was used for the extraction of the metals from real sample.

The results showed that the ratio (%) was not satisfied.

From literature review, many authors strongly recommended the moderate concentration of both acids whose the values were ranging from 1 to 3 M in final solution (Azouzi et al., 1998; Bermejo-Barrera, Mun˜iz-Naveiro et al., 2000; Bermejo-Barrera et al., 2001; Bermejo-Barrera, Muniz-Naveiro et al., 2001).

Successful leaching of Cu and Zn was achieved, but the Cd was partially leached.

The higher concentration was used, the better efficiency was found (Bermejo-Barrera, Mun˜iz-Naveiro et al., 2000).

Thus, a formula of leaching solution as 1:1:1 HNO3(4 M):HCl(4 M):H2O2(0.5 M) was chosen for further experiments.

In this study samples were treated with 6 mL of de-ionized water and the results were compared with the ones from leaching by 6 mL of 1:1:1 HNO3(4 M):HCl(4 M):H2O2(0.5 M) solution.

The overall found ratios were less than 15%.




1 Answer

  • 1 decade ago
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    當應用此兩個 t測試方法(Miller & Miller, 1993) 時,以臨界值是95%的信任度和6 自由度做比較 t 統計是2.447。發現從兩種方法濾出的銅與平均結果相當不同。

    這表明有機物(蛋白質氨基酸) 在控制銅的釋放過程中有重要的角色。


    因此,這改進銅的萃取效率(Azouzi 等 1998; Goodman, Green, & McPhail, 1984).



    一種溫和、合適之條件的過濾溶液應該是1︰1︰1的HNO3(0.5 M) :HCl(0.5 M) :H2O2(0.5 M) 。



    從文獻回顧中, 很多作者強烈建議最後溶液中,使用範圍在1到3M,含有兩種酸的溫和濃度。 (Azouzi et al., 1998; Bermejo-Barrera, Mun˜iz-Naveiro et al., 2000; Bermejo-Barrera et al., 2001; Bermejo-Barrera, Muniz-Naveiro et al., 2001).


    使用較高濃度,發現較好的效率。(Bermejo-Barrera, Mun˜iz-Naveiro et al., 2000).

    因此,為更進一步的實驗選擇的過濾溶液公式是1︰1︰1的HNO3(4 M) :HCl(4 M) :H2O2(0.5 M) 。

    在這項研究內樣品中,是用去6 mL的離子水處理,結果是比較以6 mL的1︰1︰1的HNO3(4 M) :HCl(4 M) :H2O2(0.5 M) 漏出的溶液。


    2008-02-10 11:14:37 補充:



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