410t/h煤粉锅炉的汞排放及其NID系统除汞特性研究

对配备有NID系统的410t/h燃煤电站锅炉的煤、底渣、飞灰进行取样,测定了样品中汞的含量。采用Ontario Hydro方法测定了NID前和ESP后烟气中汞的形态。实验结果表明,汞主要以飞灰形式排放,占总汞量的90%,烟气汞占10%。NID前和ESP后的烟气中,汞的浓度分别为21.3μg/m3~22.4μg/m3和1.93μg/m3~3.67μg/m3,说明该NID系统对烟气中汞具有相当高的脱除效率,达到83.6%~90.9%。对汞的化学形态研究表明,NID前烟气汞主要以Hg2+形式存在,占气态汞量的67%;ESP后烟气中Hg2+占气态汞量的71.8%~85.1%,Hg0的含量为零,说明烟气中Hg0在NID系统中经历一系列的氧化还原反应后,被氧化成Hg2+并吸附脱除。     

固相膜萃取-超声解吸-气相色谱-质谱法分析水中酞酸酯类化合物

酞酸酯(PAEs)是一种常用的增塑剂,由于其广泛应用已经对环境造成了污染.本研究建立了固相膜萃取-超声解吸-气相色谱-质谱分析水中酞酸酯类化合物的方法.对萃取条件、解吸条件进行了优化,确定了最佳的实验条件.在水浴温度40℃,超声功率50%的条件下超声7 min,测定水中PAEs的检出限(S/N>3)在0.05 ~0.26 μg/L之间;对不同基质空白样品进行加标回收实验,回收率在76.2%~112.3%之间,相对标准偏差小于10%.     

膜萃取-气相色谱/微分离子迁移谱检测水中的1,4-二恶烷

利用膜萃取-气相色谱/微分离子迁移谱（ME-GC/DMS）对水中的1,4-二恶烷污染物进行了检测。考察了射频电压、采样流速、膜渗透时间、Trap预富集时间等参数对检测二恶烷的影响规律。结果显示：在优化条件下,二恶烷的定量线性范围为2.0~20.0 μg/L,检出限为0.67 μg/L。实验证明,二恶烷与5种氯代烃的混合物在ME-GC/DMS的二维分离谱图中得到特异性响应,增加了识别的准确性。该研究为发展现场实时监测地下水中污染物的方法提供了重要参考。     

快速进样系统-多接收电感耦合等离子体质谱测定沉积物中汞同位素

应用六通阀与连续流冷蒸气发生器为基础,建立了测定沉积物中Hg同位素的快速进样系统-多接收电感耦合等离子体质谱法。当运行条件为进样流速1 mL/min,采集时间6 s,循环采集100次,洗液选取5%HNO_3时,NIST 3133 Hg标准溶液Hg同位素比值重复测定的标准误差小于1.2×10~(-5),UM-Almadén标准溶液中Hg同位素的测值与标称值一致。同时使用改进前后的方法对福建省九龙江河口的柱状沉积物样品进行测定,结果表明两种方法一致性良好(R~2大于0.99)。本方法实现了测定Hg同位素时的交替进样/清洗与连续测定,样品通量提高至4～5个/小时,且该装置结构简单,易于改造推广。     

汞(Ⅱ)-邻菲啰啉-刚果红缔合体系的共振瑞利散射和共振非线性散射光谱及分析应用

在pH=9.0的弱碱性环境中,Hg2+与邻菲啰啉(phen)反应形成无色螯合物[Hg(phen)3]2+,再与刚果红(CR)反应,形成三元离子缔合物Hg(phen)3CR,其摩尔比为1∶1。 此时引起共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)光谱显著增强,最大的散射波长分别位于578 nm(RRS法)、612 nm(SOS法)和352 nm(FDS法)。 在一定条件下,散射增强(ΔI)与Hg2+浓度呈良好的线性关系,检出限分别为2.32 μg/L(RRS法)、3.20 μg/L(SOS法)和1.56 μg/L(FDS法),考察了最佳实验条件和影响因素,表明本方法具有良好的选择性,并以RRS法为例研究了共存物质的影响。 据此建立了灵敏度高、选择性好、快速准确测定Hg2+的光散射新方法,该方法用于环境水样中Hg2+的测定取得满意结果。 并对RRS增强的原因和反应机理进行了讨论。     

无线磁弹性免疫传感法测定水中痕量镉

基于抗原抗体特异性结合使镉附着在免疫传感器表面导致磁弹片共振频率降低的原理,建立了应用磁弹性免疫传感法测定水中痕量镉的方法。 其共振频率变化对应于磁弹性片表面附着物的质量变化。研究了聚乙烯亚胺用量、戊二醛用量、反应时间等因素对测定的影响。在最佳条件下,测定镉的线性范围为0.90~10.0 μg/L,检出限为为0.42 μg/L。 应用本方法测定了水样中的镉,测定结果与双硫腙比色法一致,回收率为96.5%~103.6%。     

磁性石墨烯纳米粒子固相萃取与气相色谱-质谱相结合测定环境水样中的三嗪类除草剂

将磁性石墨烯作为磁性固相萃取的吸附剂与气相色谱-质谱(GC-MS)相结合建立了环境水样中7种三嗪类除草剂残留的测定新方法。对影响萃取效率的一些因素如吸附剂用量、萃取时间、样品溶液的pH值、离子强度和解吸条件等进行了优化。在优化的实验条件下,7种三嗪类除草剂的富集倍数在574~968之间。测定西玛津、扑灭津、嗪草酮、西草净、氰草津的线性范围为0.01~10.0 μg/L,莠去津的线性范围为0.05~10.0 μg/L,扑灭净的线性范围为0.01~8.0 μg/L。线性相关系数为0.9968~0.9998,检出限(S/N=3)为1.0~5.0 ng/L。将本方法应用于井水、自来水和湖水等实际水样的分析,在0.5 μg/L和2.0 μg/L下的加标回收率为79.8%~118.3%,相对标准偏差为3.6%~10.5%。该法操作简单、富集倍数高,可满足水样中三嗪类除草剂残留的检测要求。     

基于表面等离子体共振技术用鸡蛋黄抗体 IgY测定人血清中转铁蛋白

采用表面等离子体共振(SPR)方法, 用鸡蛋黄抗体(IgY)取代传统免疫检测中哺乳动物抗体IgG作为识别分子偶联于CM5传感芯片上, 对人血清中的转铁蛋白进行了检测. 考察了IgY在传感芯片上的偶联条件及芯片的再生条件. 结果表明, 在pH=4.0, IgY浓度为100 μg/mL, 流速为5 μL/min的最佳偶联条件下, SPR响应信号和转铁蛋白浓度在50~500 ng/mL范围内具有良好的线性关系, 检出限为39.56 ng/mL, 对人血清样品检测的日间变异系数<8%, 日内变异系数<5%, 平均回收率为86.22% ~94.51%.     

高效液相色谱-柱后衍生法检测养殖水体及沉积物中11种磺胺药物残留

建立了养殖水体及沉积物中11种磺胺化合物的高效液相色谱-柱后衍生分析方法。养殖水体过滤后采用HLB固相萃取柱进行净化、富集;沉积物采用甲醇/EDTA-Mcllvaine缓冲液(1:1, v/v)提取,HLB固相萃取柱净化富集。经高效液相色谱分离,用荧光胺衍生试剂进行柱后衍生,荧光检测器检测。对柱后衍生系统参数进行了优化,确定了荧光胺溶液的浓度、流速和反应温度分别为0.2 g/L、0.15 mL/min和50 ℃,磺胺化合物在0.01~1.0 mg/L范围内线性显著,其相关系数r²值大于0.99995。11种磺胺类药物在养殖水体和沉积物中的加标回收率分别为79.3%~100.7%和74.6%~95.3%,相对标准偏差为2.2%~11.0%和2.6%~10.3%,检出限(LOD, S/N=3)为0.9~5.5 ng/L和0.3~1.3 μg/kg,定量限(LOQ, S/N=10)为3.0~18.1 ng/L和1.0~4.4 μg/kg。该法可应用于养殖环境中磺胺类药物的定性定量检测,具有较好的实用性。     

顶空固相微萃取-气相色谱-质谱联用测定香水中5种合成麝香

建立了香水中5种合成麝香的顶空固相微萃取-气相色谱-质谱联用分析方法。实验选用65 μm的聚二甲基硅氧烷-二乙烯基苯(PDMS-DVB)萃取纤维,在磁力搅拌600 r/min条件下,考察了萃取温度、平衡时间、萃取时间、解吸时间、进样口温度和盐效应6个方面对实验结果的影响。优化后的条件为: 10 mL顶空瓶中加入适量用水稀释过的样品,于60 ℃平衡3 min后,顶空萃取20 min,随即插入气相色谱进样口,于250 ℃解吸3 min进行定性、定量分析。5种合成麝香在0.05～1.00 μg/g范围内线性关系良好,检出限(LOD)为0.6～2.1 ng/g。空白样品在3个浓度加标水平下(0.05, 0.50, 1.00 μg/g)的回收率为82.0%～103.3%,相对标准偏差(RSD)为1.8%～9.4%。本方法简便、准确、快速、灵敏,适用于香水中合成麝香的分析检验工作。     

Variations of mercury distribution in the water column during the course of a tidal cycle in the Yangtze Estuarine intertidal zone, China

Tidally induced resuspension processes play an important role in the release of mercury (Hg) into the water column, which increases the risk of Hg exposure to estuarine eco-systems. In order to further understand the geochemical activities of Hg in the intertidal area, the temporal variations of dissolved Hg (Hg D ) and particulate Hg (Hg P ) in the water column during the course of a tidal cycle and its geochemical processes were studied in the southern intertidal zone of the Yangtze Estuary, China. The concentrations of Hg D and Hg P varied between 37-612 ng/L and 51-638 ng/L respectively during the tidal cycle. The increase of Hg D was distinguished at the early flood tide and late ebb tide when the water flow rates were higher. The Hg D concentrations were negatively correlated with Hg P (r = 0.523, p < 0.05) and positively correlated with dissolved organic carbon (DOC) (r = 0.605, p < 0.05) in the bottom water, indicating that the Hg D released from the sediments into the overlying water was associated with the simultaneously released colloidal material in the bottom water. The main pathways for the translocation of Hg from the sediments to the overlying water include the processes of desorption from resuspended particles, advection or diffusion from sediments, and the oxidation of resuspended sulfide. The results of principal components analysis (PCA) and Pearson correlation analysis showed that the combined effects of the total suspended substrate (TSS), DOC, pH and dissolved oxygen (DO) influenced the geochemical activities of Hg in the water column during the course of a tidal cycle.     

Behavior of some macroelements,trace elments and RE in the water-sediment system

The aim of this work was to estimate the processes of sorption or desorption which take place when water of slightly higher temperature and elevated concentrations of some elements, compared to groundwater, comes into contact with aquifer sediments under aerobic conditions. The behavior of some macro-elements, trace elements and RE in the water/sediment systems, prepared as five different granulometric fractions of the sediment, was followed by INAA, AAS and titrimetric methods, under simulated natural conditions. It was found that, for the majority of elements, desorption takes place. Opposite to this, Mg and Zn are sorbed from water on all sediment granulometric fractions. The concentration of Ca as a major cation is lingering about its initial value. Na, K, Ba, Sr, Fe, Hg, Au, Sc, Sb, U, La and Ce are desorbed from all sediment fractions. The desorption from finer sediment phase was less pronounced for Fe, Hg, Au, Sc, Sb and Ce. Sorption of some elements (like Co, Cr and Zr) on smallest sediment fraction (<90 m) appears. Sorption-desorption processes, as well as water pH changes, are time dependent, continuing for some weeks, especially in the coarse sediment system. The extents of sorption and desorption for most of the determined elements indicate that the specific surface area is not a key parameter     

Internal standardization for the determination of cadmium,cobalt, chromium and manganese in saline produced water from petroleum industry by inductively coupled plasma optical emission spectrometry after cloud point extraction

In the present paper a procedure is proposed for the determination of traces of Cd, Co, Mn and Cr in petroleum industry produced water by inductively coupled plasma optical emission spectrometry. The procedure is based on cloud point extraction of these metals, as their dithizonate complexes, into the surfactant-rich phase of octylphenoxypolyethoxyethanol surfactant (Triton X-114). Extractions were carried out in solutions with salinities between 10‰ and 70‰. Since residual salinity in the surfactant-rich phase caused differences in its transport to the plasma, yttrium was used as an internal standard to correct for this effect. The simultaneous metal extraction procedure was optimized by response surface methodology using a Doehlert design and desirability function. Enhancement factors of 21, 21, 9 and 19, along with limits of quantification of 0.093, 0.20, 0.73 and 1.2 μg L^− 1, and precision expressed as relative standard deviation (n = 8, 20.0 μg L^− 1) of 5.8, 1.2, 1.7 and 5.7% were obtained for Cd, Co, Mn and Cr, respectively. The accuracy was evaluated by spike recovery tests on the high salinity water samples with salinity of 40 and 63‰.     

Investigation of acidic pharmaceuticals in river water and sediment by microwave-assisted extraction and gas chromatography–mass spectrometry

Investigations were performed along the Danube river at Budapest (Hungary) by collecting water and sediment samples simultaneously for 1 year in order to clarify the possible hazard of selected acidic pharmaceuticals (ibuprofen, naproxen, ketoprofen, and diclofenac) on the water supply used for the production of drinking water by bank filtration. In the case of water samples, the sample preparation procedure included solid phase extraction (SPE), meanwhile, in the case of sediment samples, microwave-assisted extraction (MAE) followed by dispersive matrix extraction (DME) for pre-cleaning as well as SPE for enrichment. The quantification was carried out using gas chromatography–mass spectrometry (GC–MS). The calculated recoveries were 97–99% (± 7%) for the water and 95–103% (± 12%) for the sediment samples. In the river water, ketoprofen concentration was always below the limit of quantification (LOQ) level; ibuprofen, naproxen and diclofenac could be quantified in the range of 8–50, 2–30, 7–90 ng/L. In sediments, only naproxen and diclofenac were found in the range of 2–20 and 5–38 ng/g, respectively. According to the obtained results, the concentration ratios of the two phases linearly depended on the total organic carbon content (TOC) of the sediments at each sampling date. The linear regressions were 0.925 and 0.946 for naproxen and diclofenac, respectively.     

Development of pre-concentration procedure for the determination of Hg isotope ratios in seawater samples

Hg concentrations in seawater are usually too low to allow direct (without pre-concentration and removal of salt matrix) measurement of its isotope ratios with multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). Therefore, a new method for the pre-concentration of Hg from large volumes of seawater was developed. The final method allows for relatively fast (about 2.5 L h⁻¹) and quantitative pre-concentration of Hg from seawater samples with an average Hg recovery of 98 ± 6%. Using this newly developed method we determined Hg isotope ratios in seawater. Reference seawater samples were compared to samples potentially impacted by anthropogenic activity. The results show negative mass dependent fractionation relative to the NIST 3133 Hg standard with δ²⁰²Hg values in the range from −0.50‰ to −1.50‰. In addition, positive mass independent fractionation of ²⁰⁰Hg was observed for samples from reference sites, while impacted sites did not show significant Δ²⁰⁰Hg values. Although the influence of the impacted sediments is limited to the seawater and particulate matter in very close proximity to the sediment, this observation may raise the possibility of using Δ²⁰⁰Hg to distinguish between samples from impacted and reference sites.     

Effective extraction of triazines from environmental water samples using magnetism-enhanced monolith-based in-tube solid phase microextraction

This article reports on the effective extraction of triazines from environmental water samples using magnetism-enhanced monolith-based in-tube solid phase microextraction (ME-MB/IT-SPME). Firstly, monolithic poly (octyl methacrylate-co-ethyleneglycol dimethacrylate) capillary column doped with magnetic nanoparticles was synthesized inside a fused silica. After that, the monolithic capillary column was placed inside a magnetic coil that allowed the exertion of a variable magnetic field during adsorption and desorption steps. The effects of intensity of magnetic field, adsorption and desorption flow rate, volume of sample and desorption solvent, pH value and ionic strength in sample matrix on the performance of ME-MB/IT-SPME for triazines were investigated in details. Under the optimized conditions, the developed ME-MB/IT-SPME showed satisfactory quantitative extraction efficiencies of the target analytes between 64.8% and 99.7%. At the same time, the ME-MB/IT-SPME was combined with high-performance liquid chromatography with diode array detection to detect six triazines in water samples. The limits of detection (S/N = 3) and limits of quantification (S/N = 10) were in the ranges of 0.074–0.23 μg/L and 0.24–0.68 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation, and it was found that the values were all below 10%. Finally, the developed method was successfully applied for environmental water samples such as farmland, lake and river water with spiked recoveries in the range of 70.7–119%.     

SEPARATION OF IRON AND MANGANESE IN THE EARLY DIAGENETIC PROCESSES AND ITS MECHANISM OF BIOGEOCHEMISTRY

Study shows that the reduction of iron (Fe~(3+)) and manganese (Mn~(4+)) in modern sedi-ments and the diffusive flux of the Mn~(2+) from the pore water into the overlying waterare mainly controlled by bacteria, and the distribution of the bacteria is believed to beaffected strongly by the sedimentary environment. It is the diffusive fluxes between Fe~(2+)and Mn~(2+) that lead to the separation of iron and manganese in the modern sediment at theChangjiang Mouth and near the shore. The level of the separation decreases with theincrease of the overlying water salinity and increases from the surface to the depth. Thismechanism has given a new explanation why manganese is concentrated in sediments onthe oceanic floor of ferromanganese-rich nodules.     

Quantification of human and veterinary antibiotics in water and sediment using SPE/LC/MS/MS

An analytical method was developed and tested for four different groups of veterinary antibiotics in both river water and sediment matrices. Solid phase extraction (SPE) was used to enrich and to clean up the aqueous sample. Also, Mcllvaine and ammonium hydroxide buffer solutions were used to extract the compounds from the sediment matrix. High performance liquid chromatography (HPLC) equipped with tandem mass spectrometry (MS/MS) was used to separate and quantify the samples. The range of recoveries (in percent) for tetracyclines (TCs), sulfonamides (SAs), macrolides (MLs), and ionophore polyethers (IPs) in the water matrix were 102.2–124.8, 76.6–124.3, 89.5–114.7, 82.7–117.5 with 1–13 (%) of relative standard deviation respectively with three different concentrations. For sediment, the percent recovery ranges were 32.8–114.8, 62.4–108.9, 53.4–128.4 and 51.3–105.4 for TCs, SAs, MLs and IPs, respectively. The relative standard deviation ranged from 16 – 27 (%) over three different concentrations. The limit of quantification (LOQ) was determined by two different methods and calculated to be in the range of 0.01–0.04 μg/l and 0.3–2.5 μg/kg for TCs, SAs, and MLs in water and sediment, respectively. For IPs, the LOQ was 0.001–0.003 μg/l in river water and 0.4–3.6 μg/kg for sediment. The sediment concentration measured in an agriculture-influenced river was much higher than in the overlying water matrix, indicating a high degree of sediment partitioning for these compounds.     

固相萃取-高效液相色谱-串联质谱法检测粮食及其制品中的呕吐毒素

建立了粮食及其制品中呕吐毒素的高效液相色谱-串联质谱(HPLC-MS/MS)检测方法。样品经乙腈-水(84:16, v/v)溶液提取,HLB固相萃取柱富集净化,采用HPLC-MS/MS法对目标物进行定性确证和定量分析。在Phenomenex Kinetex C18柱(100 mm×4.6 mm, 2.6 μm)上以0.3‰氨水和乙腈为流动相进行梯度洗脱分离;质谱模式为电喷雾负离子监测模式。本方法的检出限(以信噪比(S/N)=3计)和定量限(以S/N=10计)分别为20 μg/kg和50 μg/kg;在20～1000 μg/L范围内呈现良好的线性关系,相关系数(r)大于0.99。对本底空白的面粉、大麦、大豆、大米、玉米粉、木薯干、小麦等7种代表性基质进行50、100、500 μg/kg 3个含量水平的添加试验,回收率范围为75.6%～111.0%,精密度(以相对标准偏差(RSD)计)不大于13.0%。本方法准确可靠,灵敏度高,经济实用,可替代较为昂贵的免疫亲和柱和多功能净化柱,较大地降低检测成本。