固相萃取—高温裂解—气相色谱质谱法测定西台晶间卤水中溶解性有机质

采用3种固相萃取材料(C18、XAD-8/4和PPL)分离富集西台吉乃尔盐湖卤水中的溶解性有机物(DOM),通过总有机碳/总氮分析(TOC/TN)、紫外—可见光谱分析、元素分析、傅里叶变换红外光谱分析(FTIR)、高温裂解—气相色谱质谱联用仪(Py-GC/MS)等对富集的有机物进行表征和分析方法比较。结果表明,西台吉乃尔盐湖卤水中的溶解性有机物主要有多糖类,芳香类、含氮类有机物,烷烃烯烃类化合物。PPL,C18和XAD-8/4的回收率分别为40±2%,7±2%和16±1%,虽然C18和XAD-8/4回收率较低,但3种吸附剂都有各自的特点,C18较易吸附烷烃烯烃类有机物,XAD-8/4较易吸附芳香类有机物,PPL较易吸附含N类有机物和多糖类有机物。     

察尔汗盐湖钾肥生产流程中有机物的组成分析

采用Bond Elute PPL固相萃取小柱对察尔汗1×106t钾肥生产工艺流程中的盐湖卤水有机物进行分离富集,通过元素分析、紫外可见光谱分析、傅里叶红外光谱分析(FTIR)以及高温裂解—气相色谱质谱(Py-GC/MS)对富集得到的有机物进行表征。分析结果表明,察尔汗百万吨钾肥生产工艺流程卤水中,有机物的组成有烷烃烯烃类、醛酮类、含氮类、脂环类、脂肪酸类、芳香类、呋喃及呋喃衍生物类有机物。其中脂环类、脂肪酸类、芳香类、呋喃及呋喃衍生物含量较高。     

固相萃取—热裂解—气相色谱—串联质谱法测定盐湖卤水中溶解性有机质

以青藏高原地区的大柴旦盐湖湖表卤水为研究对象,采用不同的固相萃取(Solid phase extraction,SPE)材料(HLB,PPL,ENVI-18,ENVI-Carb,XAD8和XAD4)对大柴旦盐湖湖表卤水中DOM进行了分离和富集,初步建立了从高盐体系盐湖卤水中高效分离富集出具有代表性的溶解性有机质(Dissolved organic matter,DOM)的方法,系统的考察了pH,上样体积,柱流速和洗脱溶剂对DOM回收率的影响。结合傅里叶变换红外光谱分析(Fourier transform infrared spectroscopy,FTIR)、热裂解—气相色谱—串联质谱分析(Pyrolysis-gas chromatography-mass spectrometry,Py-GC/MS)进一步对盐湖卤水分离物进行了谱学表征。研究结果表明,盐湖卤水在酸性条件下(pH=2),柱流速为0.5 mL/min时有助于吸附剂对DOM的吸附,而随着上样体积的增加,DOM的回收率逐渐下降,而甲醇是比较理想的洗脱剂。大柴旦盐湖湖表卤水中的DOM主要以芳香类,碳水化合物以及部分脂肪族化合物为主,而含氮类化合物含量较少。     

ICP-AES法快速测定卤水中的硫酸根

本文建立了电感耦合等离子体发射光谱(ICP-AES)法测定卤水中硫酸根含量的方法。该方法在S 182.034 nm处的检出限为0.0324 mg/L,线性范围为0.0324 -1000 mg/L。实验研究了卤水中常见共存离子对硫酸根测定的影响情况。经国家标准物质验证,结果与标准值相符。将该方法应用于实际卤水中硫酸根的测定,方法的相对标准偏差(RSD,n=11)小于2.2 %,加标回收率为98.1 %—104.4 %。将该方法的测定值与重量法的结果进行了对比,无明显系统偏差。     

ICP-AES测定微量碘进样装置的设计及应用

针对电感耦合等离子体原子发射光谱(ICP-AES)直接测定碘灵敏度低、检出限高的问题,本文设计了一种用于微量碘测定的ICP-AES进样装置。采用该装置可大幅降低ICP-AES对碘的检出限,同时降低了卤水中常见共存离子对碘测定的干扰。采用该装置3 min可完成一次测定,方法线性范围为1.65～10 000μg·L~(-1)。将建立的方法用于实际卤水(包括南翼山油田水和达州深部地下卤水)中微量碘的测定,加标回收率为96%～104%,测定的RSD小于2%。     

盐场卤水氧化-吸附联合脱色工艺的研究

以天津汉沽盐场高镁卤水为研究对象,分析其成色原因,建立了过氧化氢氧化-氢氧化锆吸附联合脱色工艺,分别考察了脱色剂用量、温度、pH值等因素对卤水色度、CODCr及镁离子损失率的影响,确定了最佳的脱色工艺条件:用卤水处理量1%(体积比)的过氧化氢于室温下将卤水氧化2 h后,在pH值为2～3的条件下经氢氧化锆吸附脱色40 min,氢氧化锆用量为60 g/L。在此条件下,卤水色度及CODCr去除率分别可达99%和85%,镁离子的损失率可控制在1%以下,均高于目前使用的工艺方法。吸附剂氢氧化锆经脱附后可循环使用,大大降低了工艺运行成本。     

氢氧化铁共沉淀电感耦合等离子体发射光谱法测卤水中的痕量钴镍锰

用氢氧化铁共沉淀分离卤水中的钴镍锰,用1+1的王水溶解沉淀定容,电感耦合等离子发射光谱法测定。检出限为LD(Co Mn)=0.10 mg/L,LD(Ni)=0.27 mg/L,加标回收率为95.00%～102.0%,精密度(n=12)为1.05%。结果表明,本方法快速准确,可以准确测定卤水中钴镍锰。     

ICP-AES法快速测定卤水中的硫酸根

尝试建立了电感耦合等离子体发射光谱(ICP-AES)法测定卤水中硫酸根含量的方法。该方法在182.034 nm处的检出限为0.032 4 mg/L,线性范围为0.032 4~1 000 mg/L。实验研究了卤水中常见共存离子对硫酸根测定的影响。该方法经国家标准物质验证,结果与标准值相符。将该方法应用于实际卤水中硫酸根的测定,相对标准偏差(RSD,n=11)小于2.2%,加标回收率为98.1%~104.4%。将该方法的测定值与重量法的结果进行对比,无明显系统偏差。     

内蒙古哈达贺休盐湖卤水水化学特征及成因

内蒙古哈达贺休盐湖是由黑河尾闾湖演化形成的现代干盐湖。地质勘探发现其地下蕴藏有第四系上更新统砂砾层孔隙卤水,目前对其水化学特征及成因没有系统的研究报道。本文作者采集了哈达贺休盐湖24件卤水样品,并分析其常量和微量离子含量、矿化度(TDS)和pH值。结果显示,盐湖卤水水化学类型为硫酸钠亚型,pH值在6.72～7.77之间,属弱碱性卤水;TDS在59.71～172.02 g/L之间,平均值100.45 g/L,属中低矿化度;卤水常量离子中K⁺含量为0.66～3.16 g/L,平均1.60 g/L(接近和超过了综合利用的标准),K/TDS比值也高于马海、黑北凹地等深层卤水,并落在察尔汗和罗布泊晶间卤水数量级范围内。表明研究区卤水具有成钾而低矿化度的特征;微量离子中B₂O₃和Li⁺含量分别为40.09～278.21 mg/L和1.14～5.17 mg/L。K-Li-B三角当量图显示,盐湖卤水具有富K、B特征,具有综合开采钾和硼的潜在经济价值;卤水离子钠氯系数(0.79～6.15)和溴氯系数(0.11～1.8...     

四川盆地普光地区深层地下油田卤水溶解性有机质组成特征研究

采用 C18、PPL、HLB三种固相萃取材料对四川盆地普光地区一处油田卤水中的 DOM进行了富集分离并采用 FTIR和 Py-GC/MS对所分离的 DOM进行了表征。结果表明, PPL和 HLB的组合吸附剂对油田卤水 DOM的富集效率较好, C18富集效率最低。所研究油田卤水 DOM中主要含有有机酸、含硫化合物、芳香族化合物、碳水化合物、脂肪族化合物以及含氮有机物等。其中含硫有机物和有机酸所占比例较多。这可能是由于该区域海相层系中发育着多种类型的含硫物质,可通过生物地球化学作用而生成种类繁多的含硫有机物。而有机酸作为微生物生长的营养物质,又在一定程度上促进了含硫有机物的形成。通过比较发现,地质条件 /成因以及水质参数等因素都会影响油田卤水 DOM的组成特征。针对不同地域及不同形成机制的油田卤水中 DOM的结构组成做系统性研究,可为后续 DOM的有效处理提供科学依据。     

湿地土壤铁的分析测定方法比较

结合湿地土壤滞水缺氧特征,根据不同研究需要比较了现有常用的铁元素分析测定方法。通过比较发现,可用于湿地土壤铁分析测定的方法有10余种,其中全量测定以原子吸收光谱法或电感耦合等离子体发射光谱法在准确度、灵敏度和检出时间上优于各类比色法;BPDS-EDTA双络合紫外一可见分光光度法是能稳定铁价态并准确同时测定2种价态铁含量的最有效方法;鉴于湿地土壤明显的空间异质性,基于重金属分级研究而改进的连续浸提法优于经典的铁氧化物种类的独立区分;考虑到铁价态与种类的精确刻度对湿地环境变化研究的重要指征价值,价态区分与种类区分采用鲜土即时测定比风干土更能反映土壤的自然实貌。     

苯并15-冠-5—离子液体体系多级逆流萃取分离锂同位素研究

锂的两种天然同位素（6Li和7Li）在能源、环境和国防安全等领域具有重要应用价值。本文以氯化锂溶液为原料，选用苯并15-冠-5和咪唑类离子液体体系对其进行了模拟逆流萃取实验，考察了多级逆流萃取过程中锂的萃取率和锂同位素分离系数的变化规律，结果表明：经10级逆流萃取后，锂的萃取率和同位素分离系数有了明显提高，6Li富集在有机相，丰度提高了0.2996%，本文对锂同位素富集浓度和富集行为进了研究探讨。     

High-resolution mass spectrometric characterization of dissolved organic matter from warm and cold periods in the NEEM ice core

Dissolved organic matter(DOM) is an important component of ice cores but is currently poorly characterized. DOM from one Holocene sample(HS, aged at 1600–4500 B.P.) and one Last Glacial Maximum sample(LS, aged at 21000–25000 B.P.) from the North Greenland Eemian Ice Drilling(NEEM) ice core were analyzed by ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS). CHO compounds contributed 50% of the compounds identified in negative-ionization mode in these two samples, with significant contributions from organic N, S, and P compounds, likely suggesting that marine DOM was an important source in these samples. Overall, the chemical compositions are similar between these two samples, suggesting their consistent DOM sources. However, subtle differences in the DOM between these two samples are apparent and could indicate differences in source strength or chemistry occurring through both pre-and post-depositional processes. For example, higher relative amounts of condensed carbon compounds in the HS DOM(5%), compared to the LS DOM(2%), suggest potentially important contributions from terrestrial sources. Greater incorporation of P in the observed DOM in the LS DOM(22%), compared to the HS DOM(13%), indicate more active microbiological processes that likely contribute to phosphorus incorporation into the DOM pool. Although these two samples present only a preliminary analysis of DOM in glacial/interglacial periods, the data indicate a need to expand the analysis into a broader range of ice-core samples, geographical locations, and glacial/interglacial periods.     

用离心萃取器从罗布泊盐湖卤水中萃取硼的研究

研究了用2-乙基己醇作萃取剂从高浓度氯化镁卤水中萃取硼的工艺。先用分液漏斗通过单因素和正交实验优化了萃取与反萃取的工艺条件,作出了萃取与反萃等温线。结果表明,萃取最佳条件:pH=1.8,盐(MgCl_2)浓度28%以上;反萃pH大于2.3。由McCabe-Thiele图解法得到逆流萃取和反萃取级数分别为3和4级。然后用8台Ф20 mm离心萃取器进行了连续逆流萃取与反萃取硼的实验。结果表明,离心萃取器在较大的流比和转速范围内级效率达到99%以上;用4台离心萃取器进行连续逆流萃取,硼的总萃取率达到96.9%;负载有机相用4台离心萃取器进行连续逆流反萃取,硼的总反萃取率达到99.8%。     

不同有机溶剂萃取生物结皮中叶绿素a效率的比较研究

参照水体中浮游植物叶绿素a的萃取测定方法,运用丙酮、乙醇、二甲基甲酰胺（DMF）、二甲基亚砜（DMSO）4种有机溶剂对不同土质不同发育阶段自然和人工生物结皮中叶绿素a的萃取效率进行了比较研究。结果发现,不同有机溶剂从生物结皮中萃取叶绿素a的效率存在极显著差异（P<0.001）,而乙醇法的离散度最低;取样量对萃取效率总体上没有显著影响（P>0.05）,但在具体的测定中与萃取效率之间存在负相关。4种方法中,DMSO法对藻类占优势的结皮萃取率最高,DMF法对自然结皮的萃取率仅次于DMSO法,在人工结皮中最低;乙醇法和丙酮法的萃取效率普遍较低,而且与结皮属性之间没有明显规律。     

A method for the analysis of ultra-trace levels of semi-volatile and non-volatile organic compounds in snow and application to a Greenland snow pit

A method was developed to quantify a suite of organic compounds from snow melt water samples present at trace level concentrations, using a dichloromethane liquid–liquid extraction and GC–MS. Samples from a 3-m snow pit sampled in 2005 from Summit, Greenland were analyzed using the method developed, and a profile of organics over the past 4 years was compiled. Supporting data including the concentrations of total organic carbon (TOC), low molecular weight acids, and trace elements were determined using well established methods. The results show that low molecular weight acids contribute a significant percentage, up to 20%, of the measured TOC. Hopanes were measured quantitatively for the first time in Greenland snow. Hopanes, as well as PAHs, are at very low concentrations and contribute 0.0002–0.004% to TOC. Alkanes and alkanoic acids were also quantified, and contribute less than 1% and up to 7%, respectively to TOC. No apparent seasonal pattern was found for specific classes of organic compounds in the snow pit. The lack of seasonal pattern may be due to post-depositional processing.     

Extraction of Lithium from Salt Lake Brine using N523-TBP Mixture System

In this work,problems encountered by tri-butyl phosphate( TBP) in the industrialization of lithium extraction from salt lake brine were discussed in detail. The behavior of N,N-bi-( 2-ethylhexyl) acetamide( N523) during lithium extraction was investigated,and its disadvantages were analyzed in the view of practical application. An N523-TBP mixture extraction system was proposed to alleviate or avoid the defects that N523 and TBP met when they were used separately. The optimal composition of this mixture extraction system was determined to be 20% N523-30% TBP-50% kerosene.The effects of brine acidity,Fe/Li molarity ratio,phase ratio and chloride ion concentration on lithium extraction efficiency were discussed. The operation conditions in single-stage extraction were optimized as brine acidity = 0. 05 mol/L,Fe/Li molarity ratio = 1. 3,and phase ratio = 2. The high concentration of chloride ions in brine was beneficial for the extraction of lithium. The structure of the extracted complex was proposed as( LiFeCl_4·n N523·m TBP)·( 2-n) N523·( 2-m) TBP( m + n = 2) by chemical analysis and slope-fitting methods. The extraction thermodynamic functions were calculated preliminarily,and the results suggested that the extraction process was an exothermic( ΔH 0) and spontaneous( ΔG 0) reaction,and the degree of disorder increased( ΔS 0) during the extraction process. This work will give some guidance to the lithium industry of Qinghai in both the fundamental theory and practical application.     

盐湖中盐类矿物沉积过程中氯同位素效应的初步研究

采用Ｃｓ２Ｃｌ＋离子正热电离质谱测定氯同位素的方法，初步研究了盐湖卤水中盐类矿物结晶过程中的氯同位素分馏．研究结果表明，在自然条件下，盐类矿物自盐湖卤水中结晶时，３７Ｃｌ优先进入固相，这是造成盐湖卤水中氯同位素组成变化的重要因素．但在实验室条件下，盐类矿物自盐湖卤水中快速结晶时，则有相反的氯同位素分馏发生，即３５Ｃｌ优先进入固相，本文初步讨论了这种绝然相反的氯同位素分馏的机理．