石墨炉原子吸收法测定水中铊的方法改进

采用石墨炉原子吸收法测定水中铊,对样品前处理的多个细节进行改进,使前处理过程耗时缩短,回收率提高。试验表明,方法在0μg/L ～50．0μg/L范围内线性良好,相关系数r为0．9995;检出限为2．0μg/L,取样量为500 mL,富集50倍时,方法检出限为0．04μg/L;实际水样测定结果的 RSD 为4．9％～8．4％;实际样品的加标回收率为94．0％～102％。     

直接测汞法和原子荧光法测定土壤中总汞的比对研究

采用DMA-80直接测汞技术,与国标方法原子荧光法对土壤中总汞的测定进行了方法比对研究。试验结果表明,直接测汞法的检出限优于原子荧光法,精密度和准确性能够满足土壤实际样品的测定,对30个实际样品分析结果的比对表明,方法间无显著差异,该方法快速、准确、无污染。     

全二维气相色谱-飞行时间质谱法分离复杂体系中7种指示剂 多氯联苯

采用全二维气相色谱-飞行时间质谱法(GC×GC TOF-MS)分析了混标样品Aroclor 1260、Aroclor 1254、Aroclor 1242中的多氯联苯(PCBs)单体,考察了在复杂体系下对7种PCBs指示剂的分离能力。结果表明,与优化柱系统的分离效果相比,136种单体的混标样品中共分离出121种单体,7种指示剂经一维和二维的保留时间及质谱定性,在121种单体的2D斑点图中清晰可辨。全二维对于复杂体系的PCBs和指示剂的分离表明其强大的分离能力和对于检测复杂体系中指示剂的分辨能力,对该类物质的定性和定量检测具有重要意义。     

气相色谱-串联质谱法测定沉积物中多环芳烃

采用ASE法提取沉积物中16种多环芳烃,以固相萃取法净化提取液,用气相色谱-串联质谱法测定。通过优化测定条件,使方法在5.00μg/L~1 600μg/L范围内线性良好,方法检出限为0.15μg/kg~0.66μg/kg。空白石英砂的加标回收率为61.9%~121%,7次测定结果的RSD为2.6%~11.1%。     

色谱、光谱及联用技术在多农药残留检测中的应用

介绍了国内外多农药残留检测的发展状况,综述了色谱法、光谱法、色谱-质谱联用技术、色谱-光谱联用法、多维气相色谱技术的特点及在多农药残留检测中的应用,指出多农药残留检测在今后的农药残留检测中将占据主导地位.     

电感耦合等离子体发射光谱法测定石化废水中的重金属

建立了硝酸加热消解后采用电感耦合等离子体发射光谱(ICP-OES)测定石化废水中重金属(As,Cd,Cr,Cu,Zn,Pb,Mn)的方法,优化了仪器工作参数,得到了线性回归方程,并对该方法进行了评价。优化后的仪器工作参数为射频功率1 150 W、雾化器流量0.70 L/min、辅助气流量0.50 L/min。各重金属元素回归方程的相关系数均在0.999 9以上,检出限为0.000 18~0.007 00 mg/L,相对标准偏差为0.1%~2.0%,加标回收率为96.3%~102.2%。该方法具有线性关系好、检出限低、精密度和准确度高、分析速度快等优点。     

自动化前处理-气相色谱串联质谱法测定淡水鱼体中的有机磷阻燃剂

应用自动化前处理设备和气相色谱串联四级杆质谱仪建立了淡水鱼体中10种有机磷阻燃剂的检测方法。该方法先采用自动索氏提取仪进行样品的提取,再应用凝胶渗透色谱净化仪和florisil柱对提取液进行两级净化,最后用气相色谱串联四级杆质谱法(多反应监测模式)对样品中的有机磷阻燃剂(OPFRs)定性定量。实验表明,凝胶渗透色谱净化系统在以乙酸乙酯∶环己烷(1∶1,V/V)为流动相,流速为5.0 m L·min-1的条件下,收集OPFRs的最佳时间为900~1 680 s;方法的检出限为0.002~0.192 ng·g~(-1)湿重,加标水平为5.000 ng·g~(-1)湿重时,平均加标回收率为48.7%~122%,相对偏差除磷酸三乙酯(TEP)(17.7%)和磷酸三(1,3-二氯异丙基)酯(TDCP)(11.9%)外均小于10%。应用该方法测定采集于东江某污水处理厂入河排污口的鱼类样品时,回收率指示物(d27-TBP)的回收率为82.4%~114%,鱼类样品中∑OPFRs的浓度范围为nd~6.41 ng·g~(-1)湿重。     

LC-MS/MS determination of pesticide residues in fruits and vegetables

The aim of the research is to evaluate pesticide residue contamination of fresh and frozen fruits and vegetables, agricultural raw material, purchased from Polish farmers for production of frozen fruits and vegetables, and the estimation of the multiresidue method effectiveness expressed as the proportion of pesticides detected in food samples to the total number of pesticides analyzed by multiresidue methods. A total of 144 samples (of black currants, red currants, raspberries, cherries, strawberries, blackberries, cauliflowers and broccoli) were analyzed using LC-MS/MS method for the determination of 60 pesticides. QuEChERS extraction, matrix-matched calibration and dynamic multiple reaction monitoring method were used. Residues of 15 compounds, mainly fungicides and insecticides, were detected in 46 samples. The percentage of samples with residues above the maximum residue levels (MRL) was 15%, whereas samples with residues below MRL were 17%. A total of 13 samples contained more than one pesticide residue. Pesticide residues were detected most often in samples of black currants (50%), broccoli (36.4%), raspberries (29%) and red currants (21.8%). The most frequently detected pesticides were carbendazim and acetamiprid. The proportion of pesticides detected during our study to the total number of analyzed pesticides amounted to 25%. It was compared to literature findings. For three fourth of multiresidue methods, the proportion was below 50% for methods developed for the analysis of less than 100 pesticides, and below 30% for methods developed for the analysis of more than 100 pesticides. It appears that a lot of efforts and means is lost on pesticides never or rarely detected in examined samples. The workload and cost effectiveness of the development and application of multiresidue methods along with the range of pesticides covered by the method should be carefully and thoroughly considered anytime when a new method or workflow is developed. Including non-targeted screenings in pesticide residue control seems to be an alternative worth considering.     

Determination of Au(III) and Pd(II) ions by flame atomic absorption spectrometry in some environmental samples after solid phase extraction

A simple and sensitive solid phase extraction method was developed for simultaneous separation and preconcentration of gold and palladium ions with N-(4-methylphenyl)-2-{[(4-phenyl-5-pyridine-4-yl-4H-1,2,4-triazol-3-yl)thio]acetyl}hydrazine carbo thioamide complex on Amberlite XAD-1180 resin before their determination by flame atomic absorption spectrometry. Some analytical parameters such as HNO₃ concentration of the sample solution, amount of complexing agent, sample volume, eluent type and volume, effects of foreign ions and adsorption capacity of the resin were investigated for quantitative recovery of gold and palladium ions. The effects of some anions and cations were also examined. Under optimum conditions, the detection limits for gold and palladium ions were found to be 0.29 and 0.19 μg L^?1, respectively. The preconcentration factor for gold and palladium was 250. After being validated by standard addition and analysis of standard reference material, the procedure was successfully applied to the analysis of sea and stream water, anodic slime, gold ore, soil and electronic waste.     

Risk Assessment of 26 Polycyclic Aromatic Hydrocarbon (PAH) Compounds in Parkıng Garages

The aim of this study was to determine the level of 26 polycyclic aromatic hydrocarbons (PAHs) at parking garages and to provide the necessary annual information based on occupational inhalation exposure and non-occupational inhalation exposure, which carry risks for the environment. For this purpose, 22 samples were collected continuously from both gas and particulates phase PAHs from two parking garages at Konya City Center, Turkey. The exposure-based risk of these samples was evaluated using concentrations of the carcinogenic PAH compounds. None of the 26 PAHs measured had values exceeding the recommended exposure limits (RELs) standard values for inhalation rate recommended by the World Health Organization (WHO). Exposure levels of gas and particulate PAHs for the occupational group and the public (children and adults who spend time in shopping centers) were found to be 0.07–28.24 μgm^?3 and 0.05–5.753 μgm^?3, respectively, representing levels two to four times higher than those at the control site. Maximum daily inhalation of B[a]Py was estimated at 1.33 ngd^?1 for exposure of the public and as 274 ngd^?1 for the occupational group. It is believed that traffic makes a substantial contribution to the PAH profile, which had relatively high concentrations of naphthalene (Napth) and coronene (Coro). Highly carcinogenic dibenzo(a,l)pyrene (B[al]Pyre) was found in the ambient air at two parking garages. Napth and phenanthrene (Phen) were the main compounds found in nearly all the tested samples. In this study, benzo[e]pyrene (B[e]Py) was used as a reference for PAHs because its concentration is stable and does not change seasonally. Considering the importance of these compounds in relation to human health, the aim of this work was to characterize and quantify the more toxic PAHs in parking garages. Conducting PAH sampling and their chemical analysis is very costly and labor intensive. This study produced data that can be a powerful tool for environmental forensics.