重金屬外文翻譯

1、Proposal of a simple screening method for a rapidpreliminary evaluation of “heavy metals”mobility in soils of contaminated sitesValentina Pinto & Francesca Chiusolo & Carlo CremisiniReceived: 23 June 2009 / Accepted: 22 February 2010# Springer-Verlag 2010AbstractPurpose Risks associated to “

2、heavy metals” (HM) soi contamination depend not only on their total content but, mostly, on their mobility. Many extraction procedures have been developed to evaluate HM mobility in contaminated soils, but they are generally time consuming (especially the sequential extraction procedures (SEPs) and

3、consequently applicable on a limited number of samples. For this reason, a simple screening method, applicable even “in field”, has been proposed in order to obtain a rapid evaluation of HM mobility in polluted soils, mainly focused on the fraction associated to Fe and Mn oxide/hydroxides。對(duì)土壤中的重金屬的污

4、染的遷移性的初步快速的簡(jiǎn)單的篩選測(cè)定方法的建議（摘要） （對(duì)“重金屬”在土壤中的污染風(fēng)險(xiǎn)聯(lián)系不只局限于他們的總重量，通常來說，和他的遷移轉(zhuǎn)化有關(guān)。在污染的土壤中很多萃取方法被又來評(píng)價(jià)重金屬的遷移轉(zhuǎn)化，但他們隨著時(shí)間的而變特別是連續(xù)抽樣，因此適用于有限數(shù)量的樣本。由于這個(gè)原因，已提出建議，以獲得一個(gè)快速的適用工作現(xiàn)場(chǎng)"，甚至一個(gè)簡(jiǎn)單的篩選方法來重金屬在土壤中的污染遷移轉(zhuǎn)化，主要側(cè)重于相關(guān)聯(lián)的鐵和錳的氫氧化物的分?jǐn)?shù)。）Materials and methods A buffer solution of trisodium citrate and hydroxylamine hydroch

5、loride was used as extractant for a single-step leaching test. The choice of this buffered solution was strictly related to the possibility of directly determining, via titration with dithizone (DZ), the content of Zn, Cu, Pb and Cd, which are among the mostrepresentative contaminants in highly mine

6、ralised soils. Moreover, the extraction solution is similar, aside from for the pH value, which is the one used in the BCR SEP second step. The analysis of bivalents ions through DZ titration was exploited in order to further simplify and quicken the whole procedure. The proposed method generically

7、measures, in few minutes, the concentration of total extractable “heavy metals” expressed as molL1 without distinguishing between elements。我們是用的材料和方法 A 緩沖溶液的鈉枸櫞酸和羥胺鹽酸作為萃取劑一步浸出試驗(yàn)。此緩沖的解決方案的選擇是密切相關(guān)的直接測(cè)定可能性，滴定法雙硫腙（ DZ），鋅、 銅、 鉛鎘的內(nèi)容通過，當(dāng)中污染的不準(zhǔn)確性是污染物中土壤中很高的礦化原因。此外，在 BCR 體感誘發(fā)電位的第二步中，使用類似提取解決方案時(shí)要出去PH值，從而進(jìn)一步簡(jiǎn)化

8、和加速整個(gè)過程被利用二價(jià)離子通過DZ滴定分析Results and discussion The proposed screening method has been developed and applied on soil samples collected from rural, urban and mining areas, representing different situation of soil contamination. Results were compared with data obtained from the BCR procedure . Conclusion

9、s The screening method demonstrated to be a reliable tool for a rapid evaluation of metals mobility. Therefore, it could be very useful, even “in field”, both to guide the sampling activity on site and to monitor the efficacy of the subsequent remediation action。 對(duì)于收集來自農(nóng)村、 城市和采礦地區(qū)代表土壤污染的不同情況的土壤樣品結(jié)果及

10、建議的篩選方法探討已開發(fā)和應(yīng)用。然后結(jié)果是與從 BCR 過程中獲得的數(shù)據(jù)進(jìn)行比較。結(jié)論證明：篩選方法是一個(gè)可靠評(píng)價(jià)金屬轉(zhuǎn)移快慢的工具。因此，在工作現(xiàn)場(chǎng)它可能是非常有用"，甚至兩個(gè)站點(diǎn)上指導(dǎo)采樣活動(dòng)和留意后續(xù)修復(fù)操作的效果。Keywords Dithizone . Extraction procedures . In-field test . 雙硫腙關(guān)鍵字。 抽取過程。 在現(xiàn)場(chǎng)試驗(yàn)Metals mobility . Screening method 金屬流動(dòng)性。 篩選方法1 IntroductionThe environmental impact of soil contaminati

11、on by toxicologically relevant metals depends not only on the total concentration but mostly on the form in which metals occur, their mobility and, consequently, bioavailability (Alloway 2005). Risks become relevant in the following 土壤中對(duì)有毒金屬污染的不僅取決于他的總濃度，通常還和金屬的反應(yīng)，流動(dòng)性，生物作用有關(guān)風(fēng)險(xiǎn)成為有關(guān)，以下所示：cases:& m

12、edium/high levels of concentration and high mobility,but also& very high levels of concentration and moderate mobility The knowledge of trace elements mobility in contaminated soils is becoming an important requisite for any further environmental evaluation: In Europe, many countries have alread

13、y adopted laws used to regulate land contamination and considering pollutant bioavailability risks (Carlon 2007) and even the Soil Thematic Strategy, concerted by the European Commission in view of a future Soil Framework Directive, underlines the need of “improvement and harmonisation of the concep

14、ts and the modeling of the transfers of contaminants from and within the soil and of the subsequent risks” (Van-Camp et al. 2004). 中等濃度或高濃度對(duì)應(yīng)的流動(dòng)性而且高濃度對(duì)應(yīng)的流動(dòng)性研究受污染的土壤中痕量元素遷移的知識(shí)成為了將來評(píng)價(jià)環(huán)境的要條件。在歐洲，許多國家已經(jīng)采取將土壤污染和污染物的生物風(fēng)險(xiǎn)納入到國家法律中甚至一些歐洲國家機(jī)構(gòu)考慮到對(duì)于將來STS的觀點(diǎn)；重視改善環(huán)境保持和諧環(huán)境的理念和重塑污染物在土壤中的遷移和土壤中和的后續(xù)的風(fēng)險(xiǎn)成為了土壤策略主題。In th

15、e last decades, many single and sequential extraction procedures (SEPs) have been developed and proposed as standard methods for the study of metals mobility (Bacon and Davidson 2008; Cappuyns and Swennen 2008; Rao et al. 2008; Pacifico et al. 2007). The most extensively used SEPs are the one develo

16、ped by Tessier et al. (1979) and the revised BCR standardised three-step sequential extraction procedure (Rauret et al. 2000), but they are time consuming and, in general, applicable on a limited number of samples selected among a larger set.。在近幾十年間，很多單獨(dú)和連續(xù)提取過程已經(jīng)發(fā)展成為作為研究金屬流動(dòng)性的標(biāo)準(zhǔn)方法。中被Tessier et al發(fā)現(xiàn)的

17、SEPs最廣泛的是和經(jīng)修訂的 BCR 標(biāo)準(zhǔn)化三步連續(xù)提取工藝是最為被廣泛利用的。但是他的缺點(diǎn)主要是它受時(shí)間的限制和對(duì)樣品有選擇性。Therefore, considering that contaminated sites to be studied are often quite wide and heterogeneous with the consequential need of a large number of samples to be analysed, there is urgency of rapid and simple screening tools for a rel

18、iable identification of the most significant sampling points, in terms of metal mobility, that can be successively characterised through standard leaching test or SEPs (Fig. 1) (Brunori et al. 2005; Pacifico et al. 2007). In fact, screening methods have some of the following characteristics: They te

19、nd to have a qualitative rather than quantitative emphasis; they normally involve little or no sample treatment; they are rapid, and the response is used for immediate decision-making, and the result obtained generally requires confirmation by a conventional alternative (Valcàrcel et al. 1999;

20、Munoz-Olivas 2004). The proposal of a simple in-field screening method is based on the foregoing considerations, and in this work, a single-step leaching test has been developed and studied in order to obtain a rapid evaluation of metals mobility in polluted soils, mainly focused on the fraction ass

21、ociated to Fe and Mn oxide/hydroxides more dependent on the pH and oxidizing variation in the soil environment (Alloway 2005) and, qualitatively and quantitatively, more representative of the risks related to HM mobility. The proposed method is less complex and more specific, in terms of soil fracti

22、on analysed, than other existing in-field screening systems such as the rapid test proposed by Jozic et al. (2009), which, moreover, involves reagents that create safety problems when used for in-field analysis。 因此，考慮到待研究污染的場(chǎng)地往往相當(dāng)廣泛和大量連續(xù)的樣品的分析，人們迫切的需要一種快速和簡(jiǎn)單的篩選工具來確定重要的取樣點(diǎn)的一個(gè)可靠的指標(biāo)。就金屬流動(dòng)性而言，這可以通過SEPs或

23、試驗(yàn)先后特點(diǎn)浸出。實(shí)際上，有以下特征篩選方法：它們的重點(diǎn)往往是定性分析而不是定量：他們通常涉及很少或沒有樣品的處理；它們快速反應(yīng)和快速的反應(yīng)結(jié)果，結(jié)果通常需要確認(rèn)有常規(guī)的替代?；谏鲜龅目紤]建議一種簡(jiǎn)單的板塊篩選方法。為了獲得在污染土壤中金屬流動(dòng)性的快速評(píng)價(jià)，所以在這的工作單步執(zhí)行浸出試驗(yàn)，主要側(cè)重于相關(guān)聯(lián)的Fe和Mn氧化物或氫氧化物的分?jǐn)?shù)在土壤中和土壤環(huán)境的PH值及氧化性的多樣和金屬流動(dòng)性的風(fēng)險(xiǎn)來決定是定性還是定量。比其他如被Jozic et al 提出的起初快速檢測(cè)涉及創(chuàng)建安全問題時(shí)用于板塊中分析的試劑現(xiàn)有的字段篩選系統(tǒng)，他提出的方法是不太復(fù)雜和更具體的土壤分?jǐn)?shù)分析。In the pres

24、ent study, a buffer solution of trisodium citrate and hydroxylamine hydrochloride at pH9.3 was used as extractant for a single-step leaching test. The choice of this buffered solution was strictly related to the possibility of directly determining, via titration with dithizone (DZ), the content of Z

25、n, Cu, Pb and Cd, which are among the most representative contaminants in highly mineralised soils. Moreover, the extraction solution is similar, aside from the pH value, which is the one used in the BCR SEP second step. The analysis of bivalents ions through DZ titration was exploited in order to f

26、urther simplify and quicken the whole procedure。 最近研究，鈉的檸檬酸和羥胺鹽酸的緩沖溶液在ph=9.3時(shí)作為萃取劑用于單步執(zhí)行浸出試驗(yàn)。此緩沖的解決方案的選擇是密切相關(guān)的直接決定它的可能性，通過用雙硫腙來滴定Zn,CuP,b,Cd,其中高礦化重金屬污染的土壤最具有代表。此外，提取解決方案是于pH 值在其中使用 SEP BCR的第二部類似。從而通過通過 DZ 滴定分析二價(jià)離子進(jìn)一步簡(jiǎn)化和快速整個(gè)過程。Diphenylthiocarbazone, or DZ, is an organic compound widely used, especial

27、ly in the past, for the colorimetric determination of various heavy metals (Sandell 1959). DZ dissolves in most organic solvents to a greater or less extent and exists in two tautomeric forms: 二苯基硫卡巴腙或雙硫腙對(duì)各種重金屬含量的比色測(cè)定是一種使用廣泛的一種有機(jī)化合物。DZ 在某種程度上是機(jī)溶劑中的溶解與存在于兩個(gè)異構(gòu)體窗體When a solution of DZ in an immiscible

28、organic liquid is shaken with an aqueous solution of a reacting heavy metal, an internal complex dithizonate is formed, which is soluble in the organic solvent and to which it imparts a colour depending upon the metal involved. Many heavy metals can be extracted as dithizonates, but the extraction e

29、fficiency and selectivity depend on the nature of the metal and on the pH of aqueous solution. Considering that DZ is a dibasic acid: 對(duì)DZ 的不相容的液體中解決方案時(shí)，是將金屬與混合充分震蕩，于是就形成了一個(gè)內(nèi)部復(fù)雜的DZ,于是就可溶在溶液中，溶液的顏色一般和金屬有關(guān)。很多金屬可以和DZ產(chǎn)生沉淀而被分離出來，但沉淀的程度取決于金屬本身的性質(zhì)和溶液的PH值。其中DZ是一種二元酸。H2DZ<=> Ht t HDZ_HDZ<=> Ht t D

30、Z2_since the secondary ionisation constant of DZ is estimated to be less than 1015, at pH9, most of the excess of DZ will be present in the aqueous phase (w) as HDZ and will form, with metal ions, a primary metal dithizonate soluble in the immiscible organic solvent (o):由于在ph=9時(shí)第二電離常數(shù)小于10-15是一個(gè)很小的數(shù)，

31、溶液中主要以HDZ一價(jià)存在和金屬反應(yīng)生成沉淀。M+(W) +2HDZ_<=>MeHDZT2 e0TIn the past, the colorimetric determination of Zn, Cu, Cd and Pb with DZ in chloroform (CHCl3) at pH9.3 was extensively used in our laboratory for in-field preconcentration of metals and preliminary analysis of fresh waters (Brondi et al. 1986).

32、 Anyway, the use of toxic CHCl3 has discouraged this procedure, and at the beginning of our work, different experimental conditions have been evaluated in order to obtain a rapid and relatively non-toxic method for heavy metals determination through DZ titration。在以前在 pH9.3 CHCl3的三氯甲烷用比色法測(cè)量，我們的實(shí)驗(yàn)室中廣泛

33、用于板塊中富集金屬及淡水的初步分析。無論如何，通過重金屬測(cè)定方法我們不提倡用有毒CHCl3，我們工作的開始，所以在不同試驗(yàn)條件得一快速和相對(duì)不含毒性 的方法是DZ滴定 。 Initially, in order to avoid a solvent-extraction step and, in particular, the use of toxic CHCl3, many studies have been carried out on DZ dissolution in homogeneous phase: a method using inexpensive anionic micel

34、lar systems, such as sodium dodecyl sulphate, has recently been applied for spectrophotometric determination of trace level mercury (Khan et al. 2005), but our trials revealed that it could not be used for titration with visual appreciation of the colour change.。起初，為了避免萃取溶劑-步驟地，特別是有毒的 CHCl3，我們使用一種廉價(jià)

35、陰離子的膠束系統(tǒng)方法，使用非極性DZ 來滴定分離：，如鈉十二烷基硫酸，最近已經(jīng)應(yīng)用的分光光度法測(cè)定痕量級(jí)別汞汗 （et al.，2005）但我們的試驗(yàn)顯示可見顏色變化的不能用它來進(jìn)行滴定。For this reason, successively, the DZ dissolution and behaviour in relatively non-toxic organic solvents such as ethyl acetate, hexane, ciclohexane, toluene and a mixture of toluene/ciclohexane have been in

36、vestigated. Anyway, only DZ in toluene showed to be a valid alternative of DZ in CHCl3 and, at pH 9.3, it can be used for a selective, sensitive, rapid and simple titrimetric determination of Zn, Cd, Cu and Pb: The proposed method generically measures, in few minutes, the concentration of total HM e

37、xpressed as mol L1 without distinguishing between elements: 1 mL of dithizone 2 nmol of M+ (Zn, Cd, Cu and Pb)。因如此，一系列的用DZ 滴定分離用到相比較無毒性如乙酸乙酯、 己烷、環(huán)己烷、 甲苯和苯的混合有機(jī)溶劑中的行為進(jìn)行了調(diào)查，但是，在ph值=9.3 是溶劑是CHCl3甲苯的DZ中的較其它顯示，它有更高的選擇性的、 敏感的、 快速的、 簡(jiǎn)易性來滴定法測(cè)定鋅、鎘、銅、鉛。通常建議的，在幾分鐘的時(shí)間，以 mol L1為單位， 元素之間總濃度沒有區(qū)別的： 1 毫升的雙硫腙 2 nmol

38、M （鋅、鎘、銅和 Pb） The proposed screening method has been applied on soil samples collected from rural, urban and mining areas and representing different situation of soil contamination. Results were compared with data obtained from the BCR procedure。應(yīng)用了建議的篩選方法從農(nóng)村、 城市和采礦地區(qū)收集和所代表的不同情況下的土壤污染的土壤樣品上取樣。然后從 BC

39、R 過程中獲得的數(shù)據(jù)進(jìn)行比較得出結(jié)果。2、Materials and methodsMaterials Sixty-nine percent HNO3, Aristar® (BDH), 40% HF Aristar® (BDH), 70% HClO4 RPE (FLUKA) and ultrapure water (18.2 Mcm1 at 25°C) obtained from a MilliQ Element System (Millipore, France) were used for 7 2samples and calibrating solution

40、 preparation and dilution. For leaching experiments, a buffer solution was prepared with 141g of trisodium citrate Na3C6H5O .2HO RPE (CARLO ERBA REAGENTI) and 19 g of hydroxylamm- monium hydrochloride NH2OH.HCl RPE (CARLO ERBA REAGENTI) dissolved in 1 L water and the pH adjusted to 9.3 with NH3 Aris

41、tar® (BDH). Acetic acid CH3COOH (J.T. BAKER), hydroxylammmonium hydrochloride NH2OH.HCl RPE (CARLO ERBA REAGENTI), 30% hydrogen peroxide H2O2 “suprapure”(Merck) and ammonium acetate CH3COONH4 (RUDI PONT) were prepared according to the BCR procedure (Rauret et al. 2000). For titration analysis 2

42、.105 M dithizone (1,5-diphenylthiocarbazone C13H12N4S (FLUKA) was prepared daily by dissolving the appropriate amount of the corresponding chemical in Toluene (J.T BAKER). Single element ICP-MS Aristar®, (BDH) standard solutions of 1,000 mgL1 in nitric acid were used for the preparation of cali

43、brating solutions. Rhodium ICP-MS standard solution Aristar® (BDH) was used as the internal standard to correct matrix interferences in ICP-MS analysis. Polypropylene Falcon Tubes (Blue Max) were used during sampling handling, and filter membranes (0.45µm Mil- lex®HV, Millipore®)

44、 and syringes BD Plastipack were used for leaching experiments. All labware used in the experiments was soaked in diluted nitric acid overnight and then rinsed with double deionised water. All the experiments were performed in triplicate,and the mean values were considered. A blank procedure was alw

45、ays evaluated.。 材料和方法；材料:69%的HNO3，Aristar ® BDH，40 高頻 Aristar ® BDH、 70 HClO4 視網(wǎng)膜色素上皮 FLUKA 和純水 182 Mcm1，從法國專家 MilliQ 元系統(tǒng)微孔，獲得的 25 ° c 條件下將樣品用和校準(zhǔn)溶液制備及稀釋。 浸出實(shí)驗(yàn)，緩沖溶液準(zhǔn)備以 141 g 鈉枸櫞酸鹽 Na3C6H5O.2HO 視網(wǎng)膜色素上皮卡羅和 19 g NH2OH.HCl 視網(wǎng)膜色素上皮卡羅 鹽酸中的溶解 1 L 水中和 ph 值調(diào)整為 9.3 NH3 Aristar ® BDH。 醋酸 CH3

46、COOH J.T.貝克，hydroxylammmonium 鹽酸 NH2OH.HCl 視網(wǎng)膜色素上皮卡羅 ERBA REAGENTI，30 過氧化氫 H2O2"suprapure"默克和銨醋酸 CH3COONH4 RUDI 蓬當(dāng)時(shí)準(zhǔn)備根據(jù) BCR 過程 Rauret et al.，2000年。 滴定分析 2.105 M 雙硫腙為 1，5-diphenylthiocarbazone C13H12N4S FLUKA 份由每天適當(dāng)數(shù)額的甲苯 J.T 貝克在相應(yīng)的化學(xué)溶解。 電感耦合等離子體質(zhì)譜 Aristar ®，BDH 標(biāo)準(zhǔn)溶液中硝酸 1000 mgL1 的單個(gè)元素用

47、于校準(zhǔn)解決方案的研制。 銠-等離子體質(zhì)譜標(biāo)準(zhǔn)解決方案 Aristar ® BDH 用于內(nèi)部標(biāo)準(zhǔn)作為更正電感耦合等離子體質(zhì)譜分析中的矩陣干擾。 用聚丙烯獵鷹管藍(lán)色最大 中采樣處理與濾膜 0.45µm 密 lex ® 高壓、 微孔 ® 和注射器屋宇署 Plastipack 用于浸出實(shí)驗(yàn)。 在實(shí)驗(yàn)中使用的所有 labware 泡稀硝酸在一夜之間，然后用雙 deionised 水沖洗。 一式三份，進(jìn)行的一切實(shí)驗(yàn)和被認(rèn)為是平均的值。 一個(gè)空的過程始終計(jì)算。Instrumentation A microwave system (Milestone 1200 Mega

48、, Italy) was used for sample digestion. All the measurements of trace elements concentrations were made using a Perkin Elmer ICP-MS Elan 6100 equipped with a cross-flow nebuliser and a Perkin Elmer ICP-OES 2000 DV equipped with Scott-type spray chamber.。 使用配備橫流 nebuliser 的珀金埃爾默電感耦合等離子體質(zhì)譜大 6100 和斯科特I

49、CP OES 2000 DV型噴水室配備的珀金埃爾默來測(cè)量所有微量元素濃度的所有測(cè)量都了，從而用儀器儀表微波系統(tǒng)里程碑來消解。Sample description and preparation The proposed screen- ing method has been developed and applied on soil samples collected from rural, urban and mining areas, representing different situation of contamination: LIS samples were collected

50、 in a rural area 200 km South-East from Rome (Italy); CAR 36 and PIN31 urban samples were collected in traffic areas of Rome, and BL0102 sample was collected from horizons of selected soil profiles in the Baccu Locci stream catchment near Muravera (Southeastern Sardinia Italy), characterised by sulp

51、hide deposit exploited since ancient times, while EP3 and P5C19 samples came from an abandoned Sb mine in an area with abundant sulphide mineralization resulting from hydrothermal activities (Manciano- Tuscany). Soil samples were air-dried at 40°C and sieved at 2 mm before their use in the expe

52、riments.樣品說明和建議的屏幕方法已開發(fā)和應(yīng)用于從農(nóng)村、 城市和采礦領(lǐng)域代表不同的污染情況收集的土壤樣品的制備：LIS 樣本是從羅馬農(nóng)村地區(qū)東南 200公里收集來的；在收集了CAR 36及 PIN31樣本在羅馬的交通區(qū)收集，并BL0102 示例所選的土壤剖面中是在附近 Muravera Baccu Locci 的視野流流域收集來的以自古以來的硫化物礦床特征的土壤，而EP3 和 P5C19 的的樣品是來自一個(gè)被遺棄的銻礦山地區(qū)豐富硫化礦熱液活動(dòng)而引致的。 土壤樣品在 40 ° C會(huì)風(fēng)干，而且在試驗(yàn)之前應(yīng)篩選出直徑2mm之內(nèi)。 Determination of total cont

53、ent The elemental composition of the soil samples was determined by analyzing several samples after digestion in microwave system with HNO3, HClO4 and HF (as determined by Brunori et al. 2005). This analytical procedure was considered reliable, having been widely experienced in the past in the netwo

54、rk of several intercomparison exercises on the same types of matrices for other trace elements. The analytical performance of the laboratory was evaluated by analysing 10 different aliquots of till 1 (soil) certified reference material (CRM) to ensure adequate quality assurance. Results of HM total

55、content in the studied soils are reported in Table 1.總濃度的測(cè)定：土壤樣品的元素組成的測(cè)定時(shí)通過分析一些被以HNO3、 HClO4 和HF高頻微波系統(tǒng)處理后的出來的。此分析過程被認(rèn)為是可靠的而過去被廣泛的應(yīng)用在通過網(wǎng)絡(luò)用相同方法追蹤其他內(nèi)在有某一定聯(lián)系的元素。該實(shí)驗(yàn)室的性能分析是對(duì)10份不同組分的試樣進(jìn)行分析直到有一份CRM可以確保質(zhì)量保證的土壤。表1是HM研究土壤中的總含量的報(bào)告結(jié)果。EP3Mine24 ± 1664 ± 304.0 ± 0.31,010 ± 9BL0102Mine30 ±

56、 1142 ± 101.0 ± 0.1152 ± 2P5C19Mine146 ± 111,560 ± 648.0 ± 0.2404 ± 5LIS 1Rural32 ± 156 ± 20.39 ± 0.02162 ± 2LIS 2Rural31 ± 154 ± 20.42 ± 0.01145 ± 1CAR 36Urban139 ± 151,026 ± 400.35 ± 0.10301 ± 6PIN 31Urb

57、an58 ± 3400 ± 500.41 ± 0.09291 ± 4Sequential extraction The BCR three-step sequential procedure (Rauret et al. 2000) was applied to different soils. The residues from step 3 were treated by the procedure used for determination of the total trace element content of the soil sample

58、s. The analytical performance of the laboratory in the sequential extraction procedure was evaluated by analysing BCR 701 (lake sediment) CRM. 連續(xù)提取的 BCR 三步序貫過程.被應(yīng)用于不同的土壤。 第 3 步中的剩下來的被用來土壤樣品總微量元素含量的測(cè)定。 通過分析 BCR 701 湖泊沉積物 CRM 評(píng)估順序提取過程中實(shí)驗(yàn)室的分析性能。 The results obtained on CRMs (till 1 and BCR 701) always

59、substantially overlap the certified values.在CRM獲得的結(jié)果重現(xiàn)性很大所以認(rèn)證了它的價(jià)值 Leaching test For the kinetic studies, a single-step leaching test was performed: 0.5 g sample (soil) was used with 30-mL buffer solution. The tests were performed in triplicate. Polyethylene tubes containing samples and extractant were stirred using an end-over-end shaker at a speed of 30 rpm for a given time, different for each tube. At the end of the chosen mixing t