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1.
超高效液相色谱法检测地下水中苯并(a)芘   总被引：3，自引：2，他引：1  
李松  饶竹 《岩矿测试》2010,29(6):679-682
通过对荧光检测器波长、色谱柱温的选择,建立了超高效液相色谱测定地下水中苯并(a)芘的简便方法。采用Acquity C18色谱柱,流动相为甲醇,流速为0.40 mL/min,方法线性范围为0.082~200 ng/mL,检出限为0.033 ng/mL。在此分析条件下,苯并(a)芘保留时间仅为0.61 min。应用超高效液相色谱法和高效液相色谱法对地下水中苯并(a)芘的测定结果进行比较,超高效液相色谱在分析速度、分辨率和灵敏性方面,特别是在节省时间与溶剂消耗上具有显著的理论优势。  相似文献   

2.
A pair of isomeric C28-bisnorlupanes was detected in high abundance in the saturated hydrocarbon fractions of Tertiary sediments from West Greenland and the Gulf of Suez. The compounds were isolated by preparative gas chromatography and the isomers separated by liquid chromatography. On the basis of mass spectrometric and nuclear magnetic resonance data the structures were assigned to be 17α(H)- and 17ß(H)-23,28-bisnorlupane, respectively. The significance of nuclear demethylated triterpanes is discussed in terms of their generally high abundance, their uneven distribution within a given facies, and their worldwide occurrence.  相似文献   

3.
The molecular weight distributions and hydrolysable neutral sugar composition of dissolved organic carbon (DOC) was investigated in four maritime Antarctic lakes on Signy Island of different trophic status; Heywood Lake (eutrophic), Light Lake (oligo-mesotrophic), Sombre Lake and Moss Lake (both oligotrophic). Tangential flow ultra-filtration (TFU) was used to separate DOC into high molecular weight (HMW; >1000 Da) and low molecular weight (LMW; < 1000 Da) size fractions. Pulsed amperometric detection-high performance liquid chromatography (PAD-HPLC) was used to determine the hydrolysable neutral sugar molecular composition of each size fraction. Total DOC concentrations defined the trophic trend in the four lakes and ranged from 8 to 303 μM. The <1000 Da fraction of all the lakes dominated the DOC distribution, comprising 76% in Light Lake which also had the highest chl-a concentrations. Heywood Lake was relatively enriched in >1000 Da total organic carbon and had extremely high concentrations of total hydrolysable neutral sugars (11 μM) corresponding to 43% of total DOC. However, no clear pattern was apparent with regard to lake trophic status and potential sources of DOC, and the measured variations in individual aldose concentration, composition and their various molecular weight fractions.  相似文献   

4.
Higher fullerenes(C84,C90,C92,C94 and C96) were successfully isolated from the Soxhlet extract of the synthetical "Graphote Smokes" soot(GS sample) by using a big Cosmosil Buckysep(Phenomenex) column(250 mm × 10 mm) with a large injection.The fractions isolated have been determined by high performance liquid chro-matography(HPLC) and laser desorption mass spectrometry(LDMS).It is found that there are different fullerenes molecules in different fractions with retention time.The result indicates that fullerenes do exist in GS samples.Also,it excludes the suspicion to some extent that fullerene molecules might be generated by the laser desorption process in the LDMS.In addition,it also provides the experimental basis for the study of natural higher fullerenes and might be helpful to figure out the question if higher fullerenes do exist in the natural samples.  相似文献   

5.
Vertical transport of selected polycyclic aromatic hydrocarbons (PAHs) in different particle-size fractions of sandy soils was investigated by simulation experiments in soil columns. Tested soil samples were fractionized into three particle-sizes including sand, coarse silt and fine silt (2,000–50, 50–20 and <20 μm). Rainfall simulations were conducted in artificially PAHs contaminated soil columns with 30 cm length and 5 cm diameter in 40 days. PAHs were extracted from soil samples and determined by high performance liquid chromatography (HPLC). Results showed that the residue level of PAHs in fine silt fraction reached 35.85 mg/kg, which was significantly higher than those in sand and coarse silt fraction (16.28 and 11.80 mg/kg, respectively), probably because PAHs in macroporous fractions were prone to volatilize or degrade compared with that in microporous fractions. Linear relationship between the residue levels of individual PAH (R PAHs) and the value of partition coefficient (log K oc) was regressed as R PAHs = 1.55 × log K oc − 5.86, R 2 = 0.91, n = 9. These results indicated that vertical transport of the mixed PAHs in soils were controlled both by the nature of PAHs (i.e. log K oc, molecular weight), soil particle size and soil organic contents, which could influence the transport of PAHs.  相似文献   

6.
The applicability of size-exclusion chromatography (SEC) coupled online with a high resolution ICP-MS (HR-ICP-MS) to investigate the speciation of the platinum-group elements (PGE), Rh, Pd and Pt, was evaluated. Experiments were carried out to determine the efficiency of different hydrophilic and hydrophobic size-exclusion gel materials to select the optimal eluent in respect of resolution, recovery, reproducibility and limit of detection. The suitability of HR-ICP-MS as a reliable detection instrument at low pg ml−1 levels was investigated by examining possible mass interferences with Rh, Pd and Pt. Laboratory experiments demonstrated the interaction and capability of forming complexes of humic substances with PGE, demonstrating the potential role of these ubiquitous natural substances in the mobilisation of PGE in the environment.  相似文献   

7.
Intact polar lipid distributions have become a valuable tool for the study of microbial ecosystems. In order to expand the detection and interpretation of the presence of these lipids, improved analytical methods are needed. Therefore, two high pressure liquid chromatography–electrospray ionization tandem mass spectrometry (HPLC–ESI–MS2) methods, based on hydrophilic interaction chromatography (HILIC) and reversed phase (RP) chromatography were developed, taking advantage of new chromatographic possibilities such as smaller particle size and recently developed column packing material. Both were optimized to cover the broad range of compounds found in environmental samples and to cope with the associated complex sample matrices. The capabilities of the methods were tested on pure standards and an environmental sample. Both methods offer improved peak resolution and detection limit, and reduced chromatographic background at twofold shorter run time compared with the previous method based on a diol column. The HILIC method offers separation according to lipid class similar to a diol column, so can be recommended for lipid fingerprinting. The method based on RP separation offers the unique possibility of analyzing intact polar lipids and core lipids in the same chromatographic run and an alternative mode of lipid separation based mainly on side chain structure. The method is especially suitable for separation of compounds based on side chain length, degree of saturation and/or presence of acyl/ether bonds. The combination of both newly developed chromatographic methods provides a powerful tool for the analysis of lipid distributions in environmental samples at ultra-low concentration.  相似文献   

8.
Development of new techniques, enabling simultaneous determination of large numbers of elements in environmental samples, can force analysts to use certified reference materials that do not contain all the elements of interest. In this paper, the mass fractions of forty‐six major and trace elements, including rare earth elements (REE), are presented in one soil (NCS DC 77302 also known as GBW 07410) and five sediment (Metranal‐1, IAEA 405, MESS‐3, NCS DC 73309 also known as GBW 07311 and NCS DC 75301 also known as GBW 07314) certified reference materials determined by high resolution inductively coupled plasma‐mass spectrometry. The selected certified materials represent a spectrum of geological matrices often analysed in environmental studies. Measured elements include certified elements, elements listed with information values as well as new elements absent from certificates, including REEs and some other elements. REE + Y mass fractions in the river sediment reference material Metranal‐1 are reported for the first time. The results obtained are in agreement with available certified or information values.  相似文献   

9.
Peptides were released from organic matter fractions of three Italian soils (humin, humic and fulvic acids), when the samples were hydrolyzed in Ba(ON)2-saturated solution at 105°C for 2 hr. The peptides obtained were separated using electrophoresis and paper chromatography. The presence of polypeptides in the soil organic matter was indicated by: (1) their hydrolysis by pronase; (2) the amino acids released by 6 N HCl hydrolysis; (3) The comparison of i.r. spectra of humic fractions before and after hydrolysis with 6 N HCl.Attempts at isolating the native proteinaceous compounds using electrophoresis in polyacrylamide gel failed; additionally, our attempts to hydrolyze proteinaceous components enzymatically in unfractionated soil organic matter, as well as in its fractions, before and after methylation, with pepsin, papain and pronase, were unsuccessful. Pronase demonstrated a weak proteolytic activity only at very low substrate-enzyme ratios (20 : 1) in humic and fulvic fractions and in whole phyrophosphate extract. Deproteinated substrates treated with pronase also released free amino acids, suggesting autodigestion.In humin, humic and fulvic fractions we found a total amino acid content of 40–45%, 12–24% or 1–85, respectively. Amino acid recovery from single fractions was about 70–80% of the total content in the unfractionated soil.  相似文献   

10.
There is currently a lack of well‐characterised matrix‐matched reference materials (RMs) for forensic analysis of U‐rich materials at high spatial resolution. This study reports a detailed characterisation of uraninite (nominally UO2+x) from the Happy Jack Mine (UT, USA). The Happy Jack uraninite can be used as a RM for the determination of rare earth element (REE) mass fractions in nuclear materials, which provide critical information for source attribution purposes. This investigation includes powder X‐ray diffraction (pXRD) data, as well as major, minor and trace element abundances determined using a variety of micro‐analytical techniques. The chemical signature of the uraninite was investigated at the macro (cm)‐scale with micro‐X‐ray fluorescence (µXRF) mapping and at high spatial resolution (tens of micrometre scale) using electron probe microanalysis (EPMA) and laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) analyses. Based on EPMA results, the uraninite is characterised by homogeneous UO2 and CaO contents of 91.57 ± 1.49% m/m (2s uncertainty) and 2.70 ± 0.38% m/m (2s), respectively. Therefore, CaO abundances were used as the internal standard when conducting LA‐ICP‐MS analyses. Overall, the major element and REE compositions are homogeneous at both the centimetre and micrometre scales, allowing this material to be used as a RM for high spatial resolution analysis of U‐rich samples.  相似文献   

11.
A combined geochronological and geochemical investigation for the same domain of zircon provides valuable information on timing and genesis, particularly in the case of multi‐growth metamorphic zircon. A high spatial resolution concurrent analytical method for zircon U‐Pb age and rare earth element content was successfully achieved in this study, using a multi‐collector secondary ion mass spectrometer (SIMS) at a ~ 8 μm diameter scale. Special instrument parameters were employed, including a high mass resolution of approximately 15000 applied to replace the previous energy filter method, and a dynamic multi‐collector mode used to reduce the measurement time to 18 min per analysis. Six zircon reference materials yielded precise and accurate 206Pb/238U ages, which are comparable to those obtained by the ordinary mono‐collector method, but with 2–3 times higher spatial resolution. All zircon grains measured in this study showed enriched heavy‐REE (HREE) contents consistent with previously reported values determined by LA and solution ICP‐MS methods. The light‐REE (LREE) mass fractions measured using both SIMS and LA‐ICP‐MS methods in this study, although with quite different volume, show consistent results within uncertainties.  相似文献   

12.
Gel permeation chromatography (GPC) using a high performance liquid chromatography (HPLC) system was studied for the separation and enrichment of steroid and hopanoid hydrocarbons from crude oil for stable carbon isotope analysis. A crude oil sample was pretreated using silica gel chromatography and 5A molecular sieve to remove polycyclic aromatic hydrocarbons and n-alkanes. The GPC behavior of both the pretreated saturated hydrocarbon fraction of the oil and standard steroid [5α(H), 14α(H), 17α(H) C27–C29 steranes], hopanoid [17α(H) C27 trisnorhopane, 17α(H), 21β(H) C29–C32 hopanes] and triterpenoid [18α(H)-oleanane, gammacerane] mixtures were examined. The results indicate that 17α(H), 21β(H) hopanes as well as steranes could be enriched efficiently using GPC and that they could be obtained without removing n-alkanes from the oil saturated hydrocarbon fraction. The GPC behavior of steroid and triterpenoid hydrocarbons was controlled by molecular size and shape.  相似文献   

13.
刘明睿  汪伶俐  陈亮 《地学前缘》2019,26(4):307-314
全氟烷基酸(PFAAs)是一种新型的持久有机污染物,在各种环境介质中被频繁检出。目前,PFAAs的检测方法主要包括液相色谱串联质谱法(HPLC-MS/MS)、超高效液相色谱串联质谱法(UPLC-MS/MS)、气相色谱法和光谱类方法。但是,上述方法多存在样品前处理过程复杂、周期长、成本高的问题,不适用于PFAAs的快速检测。为此,本文建立了一种快速测量地下水和含水层介质中16种PFAAs的UPLC-MS/MS方法。水样过0.22μm滤膜后直接测定浓度,土样经过超声离心后,取上清液过滤测量浓度。本方法分别为16种PFAAs建立了低浓度(5~50μg/L)和高浓度(100~500μg/L)两条校准曲线,相关系数R^2>0.99。地下水中16种PFAAs快速检测方法检出限为0.06~1.07μg/L,回收率为75%~120%,精密度(RSD)为2.61%~9.19%(除高浓度时全氟丁烷磺酸和全氟已烷磺酸分别为11.34%和14.70%外)。含水层介质中14种PFAAs(全氟十三酸和全氟十四酸除外)方法检出限为2.69~12.33ng/g,回收率为65%~103%,精密度(RSD)为1.96%~7.22%。  相似文献   

14.
北京市大气PM2.5中多溴联苯醚污染水平与来源分析   总被引：1，自引：1，他引：0  
杨雪  刘大锰  孙俊玲 《现代地质》2010,24(2):355-361
2008年1月、9月和10月在北京城区5个采样点共采集9个大气颗粒物PM2.5样品。遵循US EPA-1614方法,采用同位素稀释、高分辨气相色谱/高分辨质谱(HRGC/MS)联用技术,测定了大气颗粒物PM2.5样品中14种多溴联苯醚(PBDEs)的质量浓度,研究了北京市城区大气颗粒物PM2.5中多溴联苯醚的污染水平、分布特征及来源。结果表明: 9个大气颗粒物PM2.5样品中PBDEs的质量浓度范围为2.82~57.94 pg/m3,平均值为15.67 pg/m3,BDE-209的质量浓度为0.34~7.32 pg/m3,PM2.5样品中PBDEs的质量浓度冬季高于秋季;高溴代联苯醚在颗粒物中的含量高,低溴代联苯醚的含量低;交通源对大气颗粒物PM2.5中PBDEs的污染贡献值很小,工业污染源贡献大于交通源,从含有溴代阻燃剂的物品释放到大气中的PBDEs对大气颗粒物PM2.5中PBDEs的污染贡献值最大。  相似文献   

15.
The REE (rare-earth) contents of sixty-three <2 μ fractions of Pennsylvanian and Permian platform sediment from the mid-continent of the U.S.A. vary considerably (ΣREE = 46–439 ppm;La/ Lu = 5.2–15.7; correlation coefficient of REE with La/Lu = 0.89), but the Eu/Sm ratios are nearly constant even in reducing environments that concentrate U (0.16–0.22). There is no correlation of REE content to clay mineralogy.Lower Permian <2 μ fractions from continental to nearshore marine sediment in Oklahoma have higher REE content (244–261 ppm) than marine facies in Kansas (46–140ppm), but <2μ Upper Permian fractions in an evaporite basin have constant but high REE content (288–281 ppm; one = 153—ppm). All Pennsylvanian <2 μ fractions from Oklahoma have high REE content (209–439 ppm), and fractions from Kansas cyclothems have variable REE content (86–438 ppm). REE content in the <2 μ fractions is inherited from the provenance, but is modified by ion exchange during weathering, transportation, or deposition. Exchangable REE tend to be concentrated in clay minerals in basic environments, but removed in acid environments.Sand and gravel-size fractions consist mostly of quartz or chert so their REE content is low (7.9–40.6 ppm) although heavy minerals may contribute a large fraction of the REE content. Unexpectedly, silt-size fractions have REE contents (74–355 ppm) that are usually lower but similar to their <2 μ fractions, and the REE contents do not correlate to clay mineral/quartz ratios. The interpretation of REE content in sedimentary rocks needs to be done cautiously due to the above factors.  相似文献   

16.
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17.
Aromatic hydrocarbon fractions from thirty gas condensates have been analysed by capillary GC and high resolution Shpol'skii spectroscopy for the determination of the relative distribution in methylphenanthrene (MP), dimethylphenanthrene (DMP) and methylpyrene (MPy) series. The measured maturity indices, MPI, DMPI and MPyI which appeared previously suitable for rocks, coals and crude oils have been tested for the recognition of rank levels of condensates. MPI and DMPI exhibit a remarkedly similar evolution which allows the differentiation of the samples analysed in these works. Such studies extend the applicability of alkylaromatic hydrocarbon ratios to the characterization of maturity level of condensates which range from immature-marginally mature to overmature samples, partially biodegraded or not.  相似文献   

18.
The siliceous skeletal remains of diatoms are a primary component of sediments, covering vast areas of the sea floor. We used high performance liquid chromatography–electrospray ionization–tandem mass spectrometry (HPLC–ESI–MSn) under high resolution time-of-flight MS (TOF-MS) conditions, as well as nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR), to investigate the distribution and molecular diversity of long chain polyamines (LCPAs) entrapped in sedimentary diatom biosilica in sediments from the Indian sector of the Southern Ocean, the Bering Sea and the Northeast Pacific. This revealed the existence of complex polyamine populations with both known and unknown structural features, including the presence of ketone and carboxylic acid groups in the LCPA backbone, functional groups that likely modulate the silica precipitating properties of LCPAs in the environment and which may constitute points of initial silica deposition (Wallace, A.F., De Yoreso, J.J., Dove, P.M., 2009. Kinetics of silica nucleation on carboxy- and amine-terminated surfaces: insights for biomineralization. Journal of the American Chemical Society 131, 5244–5250). Although various LCPA species overlapped between samples (putrescine-based LCPAs with various degrees of methylation and N-methyl propylamine repeat units were ubiquitous in all samples), clear regional differences were shown in composition and structural characteristics, likely reflecting the various diatom species contributing to the total LCPA pool for each sedimentary environment. We further show, using scanning electron microscopy and energy dispersive X-ray analysis (SEM–EDX) that LCPAs purified from diatom skeletal remains rapidly re-direct the formation of silica nanospheres in vitro, and become embedded in the precipitated silicified matrix, forming an LCPA–silica composite material. The results show that aliphatic polyamines produced by diatoms for morphogenesis of their cell walls are widespread in sediments where the fossil frustules are preserved. These newly assigned components constitute useful biological markers of diatom input to sediments.  相似文献   

19.
气相色谱法定量测定烃源岩中轻烃的含量   总被引：1，自引：1，他引：0  
王瑞  李季  蒋启贵  张彩明 《岩矿测试》2008,27(5):333-336
将烃源岩石使用低沸点溶剂密封抽提,采用高分辨毛细柱进行色谱分析,在选定的色谱条件下,能获得C5~C30的烃类物质信息。选用色谱内标法对C6~C15轻烃组分进行定量分析研究,由于轻烃组分的不同挥发性,以1-己烯作内标物来控制C6~C7烃类物质的定量,以1-壬烯作内标物来控制C7~C15(含C7)烃类物质的定量。结果表明,方法加标回收率大于85%,重复性分析相对误差小于10%。方法稳定可靠,能准确提供烃源岩中C6~C15轻烃的定量数据,有效应用于油气田勘探资源量评价中。  相似文献   

20.
Aromatic distribution patterns have been evaluated for a series of twenty-four German high volatile bituminous B to low volatile bituminous coals of Upper Carboniferous Westphalian C-, B- and A-ages using high performance liquid chromatography and glass capillary gas chromatography. The study concentrates on dicyclic and tricyclic aromatic hydrocarbons most of which have been identified by combined gas chromatography-mass spectrometry. The distribution patterns of the methylhomologs of naphthalene and phenanthrene are strongly controlled by rank. A sudden increase of individual isomer ratios at 0.9% Rm coincides with an abrupt shift of the sporinite fluorescence colour from yellow towards red. A recently developed aromatics-derived maturity parameter, the Methylphenanthrene Index (MPI), correlated well with the vitrinite reflectance data over the whole rank range. Deviations have been attributed to variations of maceral composition or migration phenomena. The influence of artificial thermal alteration (350 and 400dgC) on the aromatic distribution pattern of coal is described.  相似文献   

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