土壤和白菜中低分子量有机酸的气相色谱分析

利用甲醇-硫酸混合液(体积比10∶7)对土壤和白菜中低分子量有机酸同时进行提取和甲酯化衍生,然后利用二氯甲烷液-液萃取,气相色谱法分析。土壤中7种低分子量有机酸(草酸、丙二酸、反丁烯二酸、琥珀酸、马来酸、L-苹果酸、柠檬酸)的添加回收率为81.93%~95.58%,白菜中的添加回收率为84.78%~106.99%,方法的检出限为0.72~4.14 mg/kg。方法用于测定根际、非根际土壤和白菜根系、茎叶中的低分子量有机酸,结果准确可靠。     

加速溶剂萃取-气相色谱/质谱法同时测定土壤中拟除虫菊酯类等18种农药残留

采用正己烷-丙酮-磷酸混合溶剂为提取剂,在萃取温度100℃、压力10.3 MPa条件下,用快速溶剂萃取仪提取土壤样品,石墨碳黑氨基固相萃取柱净化,PTV大体积进样,气相色谱-质谱联法同时检测六六六(HCHs)、滴滴涕(DDTs)和10种拟除虫菊酯类农药(联苯菊酯、甲氰菊酯、氯氟氰菊酯、氯菊酯、氯氰菊酯、氟氯氰菊酯、氟氨氰菊酯、氰戊菊酯、氟氰戊菊酯、溴氰菊酯)共18种农药残留。在10～20μg/kg的添加浓度下,目标化合物平均回收率为82.84%～96.33%,相对标准偏差(RSD,n=6)为3.21%～7.34%;在20～40μg/kg的添加浓度下,目标化合物平均回收率为80.55%～103.76%,RSD(n=6)为2.56%～5.78%;在40～80μg/kg的添加浓度下,目标化合物平均回收率81.56%～95.38%,RSD(n=6)为2.19%～5.88%。方法检出限为0.11～3.40μg/kg,实际样品检测的RSD(n=3)为4.94%～8.74%。方法简单快速、灵敏度高、准确度好,可以满足土壤中HCHs、DDTs和拟除虫菊酯类农药残留的实际检测需要。     

高效液相色谱-荧光检测同时测定污泥中7种氟喹诺酮类抗生素

为了监测污泥中氟喹诺酮类抗生素(FQs)的含量和水平,建立了基于固相萃取高效液相色谱荧光检测法测定污泥中7种FQs的分析方法。污泥样品选用乙腈∶磷酸盐缓冲液(1∶1,V∶V)(pH=3)提取,以亲水亲油平衡(hydrophilic-lipophilic balance, HLB)小柱净化富集,经甲醇洗脱、浓缩后用高效液相色谱荧光检测器(HPLC-FLD)检测,采用乙腈/0.1%的甲酸作为流动相并以外标法定量。FQs在0.005～1.0 mg/L浓度范围内呈现良好线性关系,R2为0.992 7～0.999 8。添加量为0.05、0.5和1.0 mg/kg时,污泥中7种氟喹诺酮类的加标回收率为78.3%～106.4%,其相对标准偏差为3.68%～12.06%(N=5)。方法的检出限为0.001～0.01 mg/kg,方法定量限为0.004 6～0.038 4 mg/kg。用该方法对北京地区3个污水处理厂活性污泥样品中7种FQs进行分析,检出浓度范围为未检出至1.09 mg/kg。     

超高效液相色谱串联质谱法快速测定地下水和含水层介质中16种全氟烷基酸

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%。     

气相色谱—串联质谱技术检测水中安眠酮残留量

本实验建立水中安眠酮残留量的气相色谱-串联质谱联用(GC-MS/MS)分析方法。方法样品采用乙酸乙酯提取,浓缩后甲醇定容待测。采用GC-MS/MS分析时,安眠酮在15 mins内流出。对采集的水样进行两种浓度的加标质控,回收率均在70%以上,相对标准偏差(RSD)在3.0%以内。在0.05~1.00 mg/L的浓度范围内呈线性关系,相关系数大于0.999。检出限为0.50μg/L。该方法可准确用于环境水样中安眠酮残留的定量分析,灵敏度、精密度和准确度均满足残留检测的分析要求。     

基于小麦籽粒降Cd率及土壤Cd形态变化评价蚯蚓对Cd污染土壤的修复效果

本研究基于小麦籽粒降Cd率、土壤中Cd生物可利用态(DTPA-Cd)含量和土壤Cd移除率评价蚯蚓(赤子爱胜蚯蚓)对两种Cd污染农田土壤(河南潮土及河北褐土)的修复效果。研究结果表明：两种土壤中,添加0.5%和1.0%(蚯蚓鲜重/土壤干重)蚯蚓均能够明显降低小麦对Cd的富集,改变Cd在小麦植物器官中的分布,显著降低小麦籽粒中Cd含量(P<0.05),籽粒降Cd率达到31.1%~43.5%,促使小麦籽粒生物量增加35.5%~62.7%。添加0.5%和1.0%蚯蚓可显著降低土壤中生物可利用态Cd(DTPA-Cd)含量(P<0.05),DTPA-Cd含量下降29.1%~40.8%,有利于促进土壤中生物可利用态Cd向生物不易利用的形态转化。0.5%和1.0%蚯蚓添加使土壤中Cd移除率达到6.05%~11.88%,明显高于对照组(P<0.05),说明蚯蚓具有很好的Cd污染农田土壤修复潜力。在低Cd污染农田土壤中,蚯蚓可以降低土壤中Cd含量,减少小麦对Cd的富集,同时降低小麦籽粒Cd含量,这一研究结果对于修复低Cd污染农田土壤、保证农产品安全和实现“边生产边修复”具有重要意义。     

电感耦合等离子体质谱法测定井间示踪剂中稀土元素

以甲醇为稀释剂,用电感耦合等离子体质谱法快速测定稀土示踪剂中17个稀土元素。研究表明,在优化的稀释剂甲醇浓度为2%(体积分数)、pH<2.47的条件下测定稀土元素,方法精密度(RSD)为1.23%~2.83%,日间6次测定的精密度为2.25%~4.76%,各稀土元素线性关系良好,检出限为2.0~9.0 ng/L;17个稀土元素的加标回收率为85%~108%,满足痕量元素分析要求。     

气相色谱法测定地下水中拟除虫菊酯有机氯百菌清等24种农药残留

拟除虫菊酯类、有机氯、百菌清等农药均属于电负性强化合物,采用气相色谱-电子捕获检测器(GC-ECD)检测具有较高的灵敏度,但由于拟除虫菊酯类农药分子量较大,其灵敏度显著低于有机氯,使得各类化合物进行分类检测的流程长、分析效率低。本文通过优选分析色谱柱和进样口温度等条件,利用气相色谱的色谱柱程序升压功能实现了多类别24种农药残留的快速、准确测定。实验中以正己烷为溶剂进行液液萃取,Florisil固相萃取柱净化,选择有机氯专用色谱柱(RTX-CLPesticides 2)进行分析,GC-ECD仪器在0.5~6000 ng/mL浓度范围内呈线性,方法检出限为1.00~12.00 ng/L,低、中、高三个浓度水平的加标回收率分别为80.3%~116%、79.9%~117%、85.7%~102%,相应的精密度(RSD,n=7)为1.5%~6.8%、1.3%~7.6%、1.1%~6.8%。本方法选用的有机氯专用色谱柱(RTX-CLPesticides 2)对多组分、多类别目标化合物有更好的分辨率,较通用型色谱柱(DB-5MS)更具分析优势;采用的色谱柱程序升压技术解决了拟除虫菊酯类化合物在气相色谱柱中停留时间过长而导致的低灵敏度、峰拖尾等技术难题。此方法灵敏、经济,分析通量高,可有效地同时分析多种类农药残留物质。     

巯基改性凹凸棒石黏土对土壤有效态镉及油菜吸收镉的影响

重金属不可降解,长期存在于土壤环境会严重影响作物安全。添加巯基改性凹凸棒石黏土(ATP-SH)到不同Cd污染程度土壤中,进行盆栽油菜实验,以石墨炉原子吸收光谱法测定了土壤有效态Cd和油菜不同部位Cd的含量;采用SPSS讨论了ATP-SH添加量、土壤有效态Cd、油菜不同部位Cd的相关性;计算了油菜对Cd的富集系数及转运系数,探究了ATP-SH对土壤Cd的钝化效果及对油菜富集和转运Cd的影响。实验结果显示,添加ATP-SH后,土壤有效态Cd、油菜各部位Cd含量显著降低,土壤有效态Cd降低率为40.65%~74.27%,油菜根、茎、枝、菜籽中Cd降低率分别为29.36%~79.46%、41.44%~88.45%、43.19%~95.89%和38.02%~95.81%;ATP-SH添加量与土壤有效态Cd、油菜各部位Cd含量均呈显著或极显著负相关,土壤有效态Cd与油菜各部位Cd含量均呈显著或极显著正相关,油菜各部位之间的Cd含量存在明显正相关关系;对照组油菜根、茎、枝、菜籽对Cd的富集系数分别是实验组的1.42~4.87倍、1.71~8.66倍、1.92~24.43倍、1.61~23.76倍,油菜各部位Cd的转运系数的大小是茎＞枝＞菜籽,且茎远大于枝和菜籽,是枝和菜籽转运系数的3.5~25倍。综上,ATP-SH能降低土壤Cd的生物有效性,阻隔土壤Cd向油菜迁移。     

土壤中25种有机氯农药和多氯联苯的气相色谱分析方法研究

研究了土壤中17种有机氯农药和8种多氯联苯组分的气相色谱分析方法。采用加速溶剂萃取技术提取,优化了萃取条件。提取液用固相萃取技术进行净化,采用20 mL含3%(体积分数)甲苯的正己烷-乙酸乙酯(体积比8∶2)进行淋洗,得到很好的净化效果。方法检出限在0.06~0.27μg/kg,线性范围在1.38~55.2 ng/mL,目标化合物的平均添加回收率在65%~97%,相对标准偏差(RSD,n=6)小于17.11%。方法快速、灵敏、准确,适合批量样品的分析。     

薄膜梯度扩散(DGT)-UPLC-MS/MS法测量地下水中26种抗生素

近年来地下水中抗生素污染持续受到关注. 由于抗生素含量一般为痕量级, 对地下水样中抗生素的采样提取检测提出了很高的要求. 利用薄膜梯度扩散法建立了原位富集地下水中抗生素的采样方法, 成功富集了磺胺类、喹诺酮类、四环素类、大环内酯类等抗生素; 同时, 应用超高效液相三重串联质谱法建立了分析地下水中26种典型抗生素的检测方法, 优化了提取条件. 结果表明, 整套采样及测试方法对地下水中抗生素分析具有较好的富集效果和检测灵敏度. 地下水原位富集采样时间20~30 d为宜, 26种抗生素的仪器检出限为0.002~0.074 ng/L, 平均回收率为47.7%~94.6%, 精密度4.45%~10.84%. 薄膜梯度扩散法原位富集采集地下水中抗生素的采样方式操作简单, 结合三重串联四级杆液相色谱能够实现地下水中抗生素的痕量分析.     

不同超富集、富集植物-玉米间作模式对玉米中镉吸收、转运的影响研究

为了研究Cd污染条件下,玉米分别与苋菜、黑麦草、龙葵间作对重金属Cd吸收和转运的特点,从而选择适宜与玉米间作的富集植物,同时达到修复重金属Cd污染土壤的目的。该文以镉(Cd)污染的河南棕壤黏土为供试土壤,通过盆栽试验,基于玉米各器官中Cd含量、富集系数、转运系数、土壤有效态Cd含量的变化,研究了间作苋菜、黑麦草、龙葵对玉米各器官Cd的积累特性的影响及其迁移转运机制。结果表明：(1)龙葵、苋菜、黑麦草间作使得玉米地上部Cd含量显著性降低(P<0.05),其中以籽粒中Cd含量的下降最为显著。间作苋菜、黑麦草、龙葵,玉米籽粒中Cd含量分别下降了67.6%、75.7%和79.9%。(2)间作苋菜、黑麦草、龙葵使得玉米的富集系数较单作处理下玉米的富集系数分别下降了49.3%、39.7%和68.5%,且差异达到显著水平。(3)与苋菜、黑麦草间作相比,间作龙葵的玉米转运系数分别下降了27.5%、24.2%,且差异均达到显著水平。通过对人体每天摄入Cd量的安全值计算得出间作后土壤中Cd全量应低于2.26 mg·kg-1,土壤有效态Cd含量低于0.88 mg·kg-1。该污染农田在间作模式下,食用玉米Cd暴露对居民健康不存在风险。间作苋菜、黑麦草、龙葵能够抑制玉米对Cd的吸收,同时阻控玉米地上部Cd向地上部的转移,尤其是向籽粒转移。通过间作苋菜、黑麦草、龙葵,不仅降低了主栽作物玉米的Cd累积量,实现玉米安全、优质种植,同时也达到了修复污染土壤的目的。     

快速溶剂萃取(S-916)/GC-MS法测定土壤中15种多环芳烃

本文建立了S-916快速溶剂萃取仪(Buchi瑞士)快速萃取-气相色谱-质谱仪(GC-MS)联用测定土壤中15种多环芳烃(PAHs)含量的方法。土壤样品经正己烷、丙酮快速溶剂萃取,除水浓缩后,利用硅酸镁小柱进行净化,直接进GC-MS测定。结果表明,在5.01000.0μg/L浓度范围内,15种PAHs的相关系数均在0.996以上,RF RSD<12%,加标回收率在80%117%之间,15种PAHs的最低检出限均低于0.40μg·kg^-1.该方法灵敏、快速、准确可靠,完全满足实验室对土壤中PAHs的检测要求,可为土壤中多环芳烃(PAHs)的污染情况提供快速检测依据。     

The distribution and ecological risks of antibiotics in surface water in key cities along the lower reaches of the Yellow River: A case study of Kaifeng City,China

A large number of antibiotics have been discharged into rivers by human activities, posing a threat to aquatic ecosystems. The surface water of the Yellow River Basin also suffers antibiotic pollution, which hinders the improvement in the aquatic ecological environment. This study investigated and analyzed the characteristics and assessed the ecological risks of antibiotic pollution in surface water bodies such as canals, rivers and fish ponds in Kaifeng, Henan Province, which is a key city along the lower reaches of the Yellow River. The test results are as follows. A total of 15 types of antibiotics were detected in the surface water. They had a total antibiotic concentration of 12.2–249.9 μg/L, of which tetracyclines (TCs) and quinolones accounted for the highest percentages. Six types of quinolones had detection rates of up to 100%, and doxycycline (DC) and oxytetracycline (OTC) had average concentrations of 29.52 μg/L¹ and 13.71 μg/L, respectively. The major canals with water diverted from the Yellow River had total concentrations of quinolones and TCs of 22. 0 μg/L and 14.9 μg/L, respectively, which were higher than those in previous studies. This phenomenon may be related to the decrease in the water flow of the Yellow River during the dry season and the increase in the antibiotic consumption of residents in the context of the Covid-19 outbreak. The upper reaches of the Huiji River in the Xiangfu District had higher antibiotic content than other districts in Kaifeng. Specifically, TCs accounted for 72.38%–91.84% of all antibiotics, and the DC and OTC concentrations were significantly higher than other antibiotics in the upper reaches. As indicated by the ecological risk assessment results, TCs had the highest ecological risks to green algae. Among them, DC had medium-high risks; TC, OTC, and chlortetracycline (CTC) had medium-high risks; trimethoprim (TMP) and lomefloxacin (LOM) had low risks; other TC antibiotics had no risk. Compared with green algae, most antibiotics showed higher ecological risks to daphnia and lower ecological risks to fish. DC and OTC dominate antibiotic pollutants in the surface water in Kaifeng City, and especially in Xiangfu District, where DC and OTC have medium-high risks. The TCs in the major Yellow River showed medium risks to both green algae and daphnia. It can be speculated that the antibiotic pollution in the Yellow River might pose a certain threat to the ecological security of water in Kaifeng City.©2022 China Geology Editorial Office.     

Veterinary antibiotics contamination in water, sediment, and soil near a swine manure composting facility

Antibiotics have been commonly used to prevent animal diseases and promote livestock productivity. However, its release into the surrounding environments leads to ecological disturbance and risks to human health. This study was conducted to monitor the occurrence and seasonal variations of antibiotics in water, sediment, and soil close to a swine manure composting facility, Korea. Various types of antibiotics such as tetracyclines (TCs) including tetracycline, chlortetracycline, and oxytetracycline, and sulfonamides (SAs) including sulfamethazine, sulfamethoxazole, and sulfathiazole were measured by the high-performance liquid chromatography-tandem mass spectrometry via a solid-phase extraction. In the results it was identified that the variations of measured antibiotics’ concentrations in water, sediment, and soil are depending on the season. The observed concentration levels of TCs were higher in winter than in summer season, indicating that the low temperature is a parameter attributing to interruption of its degradation in water, sediment, and soil. The concentration levels of SAs were significantly higher than those of TCs and in general, all measured antibiotics’ concentrations were also in general higher in Korea when compared to those in other countries. The long-term monitoring of antibiotics’ residues in aquatic and terrestrial environments is necessary.     

北京通州某改造区土壤中DDTs和HCHs的地球化学特征及风险评价

选取北京通州环球影城附近某改造区为研究区域,共采集15件表层土壤样品,主要分析了该地区土壤中DDTs和HCHs的空间分布地球化学特征;采集垂向样品,并分析了DDTs和HCHs在土壤垂向剖面中的分布情况。表层土壤样品中大部分的DDTs和HCHs有检出,ΣDDTs的残留量为494~19615 μg·kg-1,ΣHCHs为082~1021 μg·kg-1。土壤垂向剖面分析结果表明,DDTs部分有检出,两剖面中残留量整体随深度变化不明显,但局部出现突变现象;HCHs全部检出,两剖面中残留量整体随着深度增加不断减少。参照国家相关标准对该区土壤环境整体进行评价,初步分析通州区环球影城地区土壤中残留DDTs除个别点符合二级标准外,其余都处于一级标准,残留风险较低;土壤中残留HCHs基本符合一级标准。结合不同异构体之间含量特征及分布,认为该地区局部近期可能存在HCHs输入现象。最后,对该改造区进行了健康风险评价,结果表明该区DDTs和HCHs在致癌风险和部分非致癌风险方面影响较小。     

液-液萃取-气相色谱法测定水中9种有机氯农药

采用正己烷液-液萃取法提取,气相色谱法-电子捕获检测器测定水中9种有机氯农药。优化了实验条件:添加两种替代物作为分析过程的质量监控;使用浓硫酸磺化法净化去除杂质;采用Rtx-5MS和Rtx-1701柱双柱定性,保证数据准确可靠。9种有机氯农药的方法检出限为0.0017～0.0079μg/L,回收率为74.7%～105.1%,相对标准偏差(RSD,n=7)为4.2%～9.3%,9种农药在0.5～100μg/L内与峰面积呈良好的线性关系。方法检出限低,准确度和精密度高,简便,适用于批量样品的分析。     

A Comparison of In Situ Analytical Methods for Trace Element Measurement in Gold Samples from Various South African Gold Deposits

Trace element concentrations in gold grains from various geological units in South Africa were measured in situ by field emission‐electron probe microanalysis (FE‐EPMA), laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and synchrotron micro X‐ray fluorescence spectroscopy (SR‐μ‐XRF). This study assesses the accuracy, precision and detection limits of these mostly non‐destructive analytical methods using certified reference materials and discusses their application in natural sample measurement. FE‐EPMA point analyses yielded reproducible and discernible concentrations for Au and trace concentrations of S, Cu, Ti, Hg, Fe and Ni, with detection limits well below the actual concentrations in the gold. LA‐ICP‐MS analyses required larger gold particles (> 60 μm) to avoid contamination during measurement. Elements that measured above detection limits included Ag, Cu, Ti, Fe, Pt, Pd, Mn, Cr, Ni, Sn, Hg, Pb, As and Te, which can be used for geochemical characterisation and gold fingerprinting. Although LA‐ICP‐MS measurements had lower detection limits, precision was lower than FE‐EPMA and SR‐μ‐XRF. The higher variability in absolute values measured by LA‐ICP‐MS, possibly due to micro‐inclusions, had to be critically assessed. Non‐destructive point analyses of gold alloys by SR‐μ‐XRF revealed Ag, Fe, Cu, Ni, Pb, Ti, Sb, U, Cr, Co, As, Y and Zr in the various gold samples. Detection limits were mostly lower than those for elements measured by FE‐EPMA, but higher than those for elements measured by LA‐ICP‐MS.     

不同碳酸盐岩和土层厚度下土壤微生物数量及生物量的研究——以贵阳市花溪区为例

碳酸盐岩发育土壤的厚度变幅大,通过野外挖掘调查,在贵阳市花溪区分薄土、中土及厚土3种土层类型研究喀斯特地区不同土层厚度下微生物数量及生物量,结果表明:随着土层厚度的增加,土壤的细菌、真菌、放线菌及微生物总数逐渐增加;细菌在土壤微生物中占据了绝对优势,在石灰岩及白云岩发育土壤的各土层中分别占88.13%、85.71%、87.36%、85.00%及77.78%;石灰岩发育的土壤从薄土到厚土微生物量碳（C）、氮（N）、磷（P）的含量逐渐增加,分别增加15.15 mg·kg-1、2.82 mg·kg-1、0.18 mg·kg-1,白云岩从薄土到中土微生物量C、N、P的含量分别增加5.13 mg·kg-1、0.39 mg·kg-1、0.10 mg·kg-1;在同等厚度下石灰岩发育的土壤微生物量N、P含量明显低于白云岩发育的土壤,中土中差异最大,分别相差0.90 mg·kg-1和0.21 mg·kg-1,而石灰岩发育土壤的中土中微生物量C的含量则高于白云岩发育的土壤,高17.31 mg·kg-1;探讨相关性,pH值对微生物量C、P有显著影响（p<0.05）,全P含量对微生物量P有极显著影响（p<0.01）。