土壤中铅、砷、铬、铜和锌含量的连续快速测定

建立了土壤中铅、砷、铬、铜和锌含量的连续快速测定方法。土壤样品经微波消解,用同一份消解液,分别连续测定土壤中的铅、砷、铬、铜和锌含量,铬、铜和锌采用火焰原子吸收光谱法,铅和砷采用氢化物发生-原子荧光光谱法。采用本方法,对环境土壤标准样品ESS-1黑钙土(GSBZ50011)和ESS-3红壤(GSBZ50013)进行多次测定,检测结果与标样的推荐值吻合。经统计计算,回收率为95.2%—103.6%,精密度RSD均小于7%。本法操作简单快速,光谱测定结果已成功地用于无公害水果和蔬菜生产基地的土壤环境质量评价。     

一次性消解-原子吸收光谱法、原子荧光光谱法检测水产品中铅、镉、铜、锌和砷

采用湿法消解一次性处理水产品,塞曼石墨炉原子吸收光谱法测定铅、镉、铜,火焰原子吸收光谱法测定锌、氢化物发生-原子荧光光谱法测定砷.该方法简便、快速,通过优化前处理和上机条件,在最优条件下进行测试,铅、镉、铜、锌、砷的检出限分别为0.012、0.001、0.008、0.089、0.009mg/kg,回收率范围为87.6%-110%,相对标准偏差为3.9%-6.8%.通过测定有证标准物质,证明该方法具有很好的准确度.     

浊点萃取-石墨炉原子吸收法测定高盐样品中的痕量铅

在pH 6～7的缓冲体系中,样品溶液中的痕量铅与加入的吡咯烷二硫代氨基甲酸铵(APDC)为络合剂形成稳定的配合物。通过70 ℃恒温水浴3 h,铅配合物被萃取到表面活性剂相并与水相分开。 分离后的表面活性剂相室温就可配成上机待测样液。 此法不但将大量基体离弃在水相,从而消除高盐带来的高背景信号干扰,并将水样或1%食盐溶液的痕量铅富集10～100倍。用氘灯校正背景石墨炉原子吸收法进行测定,方法检出限：食盐0.000 5 μg·g-1,水样0.01 μg·L-1。回收率为92.3%～104%。用于食盐、海水、井水中痕量铅的测定,结果令人满意。     

沉淀富集-火焰原子吸收光谱法测定水中的铅和镉

水样用Mg（OH）2沉淀,沉淀富集后采用校准曲线法,火焰原子吸收光谱法直接测定了水样中的铅和镉。所测定的水样中铅和镉的含量远低于国家限定标准,采用此方法回收率为70%—110%。本法简单、快速,结果令人满意。     

氧化态石墨烯/铋膜修饰玻碳电极测定水中铅离子

制备了氧化态石墨烯修饰玻碳电极,并预镀铋膜,采用了示差脉冲溶出伏安法对水中的铅离子含量进行测定,考察了缓冲溶液pH值、沉积电位、沉积时间对铅离子测定的影响.通过实验条件优化,对浓度在0-3.00×10-7mol/L范围内的铅离子进行测定,铅离子浓度与溶出峰面积线性关系良好,检出限是1.00×10-8mol/L.结果表明,方法检测灵敏度高、重现性好,可实现水样中铅离子的快速测定.     

Meso-5,10,15,20-四(4-甲氧基苯基)卟啉荧光熄灭法测定铅

基于铅对荧光试剂 Meso- 5 ,10 ,15 ,2 0 -四 (4 -甲氧基苯基 )卟啉 (TMOPP)的荧光熄灭 ,建立了测定微量铅的荧光分析方法。在 p H9.5的 Tris- HCl缓冲体系中 ,最大激发波长和发射波长分别为 4 2 4 nm和6 5 7nm,测定铅浓度的线性范围为 5 .5 0× 10 -7— 7.5 0× 10 -5mol/ L,检出限为 8.5 0× 10 -8mol/ L。用于环境水样中铅含量的分析 ,结果满意。     

微量注射进样导数火焰原子吸收法测定油料作物中铅锌

采用微量注射进样导数火焰原子吸收法测定油料作物黄豆、花生、葵花子和芝麻中铅、锌含量,采用导数测量系统使检测灵敏度提高了5.6～8倍,检出限改善了8.8～10.5倍,经测定,黄豆、花生、葵花子、黑芝麻、白芝麻中铅含量分别为:4.638,3.420,1.076,0.304,1.996μg·g~(-1),锌含量分别为:34.72,28.69,64.61,20.55,18.97μg·g~(-1)。方法的灵敏度、检出限、相对标准偏差分别为:铅:0.0522,0.242μg·mL~(-1),3.50％,锌:0.0131,0.000452μg·mL~(-1),2.9％。     

电感耦合等离子体-原子发射光谱法快速测定粉条中的7种金属元素

以带电荷注入式检测器的等离子体光谱仪快速测定粉条中的铅、镉、铬、砷、镍、铜、锌7种重金属元素的含量.该方法简便、快速且具有比化学法更低的检出限,加标回收试验结果表明,回收率为90%-114%,RSD均小于8%.     

微波消解ICP-OES法测定PM2.5中金属元素

重金属具有不可降解性,细颗粒物（PM2.5）中重金属可随呼吸进入体内,对人体构成潜在的威胁。因此,有必要针对颗粒物中重金属元素的测定方法进行研究。用玻璃纤维滤膜采样、密闭微波消解进行前处理,建立了电感耦合等离子体发射光谱仪（ICP-OES）测定PM2.5中铅、锌、铜、镉、铬的分析方法。考察了微波消解体系,通过信噪比选取了铅、锌、铜、镉、铬的最佳分析谱线和最优仪器测试条件,其结果为：（1）HNO₃-H₂O₂消解体系比HNO₃-HCl和HNO₃-H₂SO₄消解体系更稳定、更彻底;（2）铅、锌、铜、镉、铬的最佳分析线分别为220.353,213.857,327.393,228.802,267.716 nm;（3）仪器最优测试条件为射频功率1 300 W,蠕动泵流速1.5 mL·min-1,冷却气流量15 L·min-1,载气流速0.8 L·min-1。本方法元素的检出限为2.02×10-3～8.20×10-3μg·mL-1,滤膜样品测定的相对标准偏差（RSD,n=6）为1.86%～2.82%,加标回收率为91.6%～103.7%。对重庆市中科院万州监测点细颗粒物中铅、锌、铜、镉、铬的含量进行了分析,结果表明：万州城区细颗粒物没有受到镉和铬的污染,细颗粒物中铅处于潜在污染水平,锌和铜处于轻度污染水平。     

流动注射在线螯合树脂双柱预富集火焰原子吸收法测定痕量铜、铅、镉和锰

本文采用流动注射在线阳离子螯合树脂双柱预富集 火焰原子吸收法 ,测定了痕量的铜、铅、镉和锰 ,灵敏度分别提高 33、5 0、37和 2 9倍 ,分析速度为 6 0次·h-1;对于 0 0 5 μg·mL-1Cu2 +、0 2 5 μg·mL-1Pb2 +、0 0 2 5 μg·mL-1Cd2 +和 0 0 5 μg·mL-1Mn2 +溶液 ,测定的相对标准偏差分别为 2 2 1%、3 2 4%、1 93%和3 6 6 % (n =11) ;对标准物质 (人发、小麦及猪肝 )进行了测定 ,结果与标准值相符。此法应用于饮用水和环境水样中铜、铅、镉和锰的测定 ,获得了满意的结果。     

蛛丝和蚕丝化学元素X射线荧光光谱分析及其应用

采用X射线荧光光谱(XRF)方法研究蛛丝和蚕丝的化学元素组成,探讨成丝机制中金属离子的作用及生物丝性能优良的元素基础。XRF分析蚕丝中C含量是47.10%、O为29.92%、N是16.52%;金属元素包括：Ca含量0.166 2%、Mg含量0.104 0%和K含量0.039 5%,而Na,Zn,Ni,Fe和Cr是微量元素。Ca和Mg元素含量高,在桑蚕吐丝机制中起着重要的作用。在蛛丝中,主要的非金属元素是：C含量44.09%、O含量26.64%和N含量22.34%。高含量的N元素可能是蛛丝优异的刚性和韧性性能的元素基础。在蛛丝中,Na含量0.268 0%、K含量0.081 4%和Mg含量0.011 6%,而Ca,Zn,Fe,Cu和Cr则是微量元素。蛛丝中Na和K元素含量高,在蜘蛛吐丝机制中可能起重要作用。运用数学统计方法研究生物丝元素组成与XRF元素分析结果吻合。     

Accuracy and repeatability of QRAPMASTER and MRF-vFA

Our purpose is to evaluate bias and repeatability of the quantitative MRI sequences QRAPMASTER, based on steady-state imaging, and variable Flip Angle MRF (MRF-VFA), based on the transient response.Both techniques are assessed with a standardized phantom and five volunteers on 1.5 T and 3 T clinical scanners. All scans were repeated eight times in consecutive weeks.In the phantom, the mean bias±95% confidence interval for T1 values with QRAPMASTER was 10 ± 10% on 1.5 T and 4 ± 13% on 3.0 T. The mean bias for T1 values with MRF-vFA was 21 ± 17% on 1.5 T and 9 ± 9% on 3.0 T. For T2 values the mean bias with QRAPMASTER was 12 ± 3% on 1.5 T and 23 ± 1% on 3.0 T. For T2 values the mean bias with MRF-vFA was 17 ± 1% on 1.5 T and 19 ± 2% on 3.0 T. QRAPMASTER estimated lower T1 and T2 values than MRF-vFA. Repeatability was good with low coefficients of variation (CoV). Mean CoV ± 95% confidence interval for T1 were 3.2 ± 0.4% on 1.5 T and 4.5 ± 0.8% on 3.0 T with QRAPMASTER and 2.7% ± 0.2% on 1.5 T and 2.5 ± 0.2% on 3.0 T with MRF-vFA. For T2 were 3.3 ± 1.9% on 1.5 T and 3.2 ± 0.6% on 3.0 T with QRAPMASTER and 2.0 ± 0.4% on 1.5 T and 5.7 ± 1.0% on 3.0 T with MRF-vFA.The in-vivo T1 and T2 are in the range of values previously reported by other authors.The in-vivo mean CoV ± 95% confidence interval in gray matter were for T1 1.7 ± 0.2% using QRAPMASTER and 0.7 ± 0.5% using MRF-vFA and for T2 were 0.9 ± 0.4% using QRAPMASTER and 2.4 ± 0.5% using MRF-vFA. In white matter were for T1 0.9 ± 0.3% using QRAPMASTER and 1.3 ± 1.1% using MRF-vFA and for T2 were 0.7 ± 0.4% using QRAPMASTER and 2.4 ± 0.4% using MRF-vFA. A GLM analysis showed that the variations in T1 and T2 mainly depend on the field strength and the subject, but not on the follow-up repetition in different days. This confirms the high repeatability of QRAPMASTER and MRF-vFA.In summary, QRAPMASTER and MRF-vFA on both systems were highly repeatable with moderate accuracy, providing results comparable to standard references. While repeatability was similar for both methods, QRAPMASTER was more accurate. QRAPMASTER is a tested commercial product but MRF-vFA is 4.77 times faster, which would ease the inclusion of quantitative relaxometry.     

The Validity and Reliability of the Reflux Finding Score

Laryngopharyngeal reflux (LPR) disease is common. The incidence of newly diagnosed cases has increased substantially due to awareness and development of new diagnostic measurements. The reflux finding score (RFS) and reflux symptom index (RSI) are believed to be useful in the assessment process, including after the initiation of therapy. However, many authors have suggested concerns about the reliability and validity of the RFS.ObjectiveTo evaluate the validity and reliability of the RFS.MethodsNinety-two patients diagnosed with LPR who had undergone 24-hour pH-Impedance tests were included. All patients underwent stroboscopy and 24-Hour pH-Impedance monitoring within thirty days. Fifty-nine patients filled out a RSI prior to stroboscopic exam. The RFS was determined by four blinded observers: one otolaryngology resident, two laryngology fellows, and one laryngologist. Stroboscopic images were reviewed again one year later to assess intrarater reliability. RFS and RSI were correlated with 24-hour pH Impedance testing.ResultsThe Kappa value between reviewers was 0.479. The percent agreement of the four observers for total RFS was 74.04%.The percent agreement between reviewers for subglottic edema was 78.77%; for ventricular obliteration was 65.55%; for erythema/hyperemia was 69.62%, for vocal fold edema was 68.32%; for diffuse laryngeal edema was 66.86%, for posterior commissure hypertrophy was 73.54%; for granuloma/granulation was 96.80%; for thick endolaryngeal mucus was 72.81%. The intrarater reliability of the four observers for total RFS was 67.5% with an intrarater reliability range of 50%–90%. The intrarater reliability for subglottic edema was 85% with a range of 70%–100%; for ventricular obliteration was 77.50% with a range of 70%–90%; for erythema/hyperemia was 65.00% with a range of 50%–90%; for vocal fold edema was 52.50% with a range of 30%–70%; for diffuse laryngeal edema was 62.50% with a range of 20%–80%; for posterior commissure hypertrophy was 52.50% with a range of 10%–80%; for granuloma/granulation was 100%; for thick endolaryngeal mucus was 55.00% with a range of 10%–90%. There was no correlation between RFS and any parameter of the 24-Hr pH-Impedance Test. RSI had a significant correlation with number of upright events (r value of 0.271, R² of 0.0733 and P-value of 0.037), total symptoms experienced (r value of 0.0.267, R² of 0.0715 and P-value of 0.041), and symptom correlation score (r value of -0.297, R² of 0.0884 and P-value of 0.022).ConclusionMany authors have expressed concerns about the reliability and validity of the RFS. In our study we found a fair/substantial interrater reliability, and a modest intra-rater reliability. We found no correlation between the RFS and 24-Hr pH Impedance testing. This study suggests that the concerns about the validity and reliability of the RFS may be warranted. This widely used clinical score should be interpreted with caution and further research and refinement should be considered.     

微波溶样—电感耦合等离子体光谱法测定粗氧锑中Hg和As

本文采用盐酸 酒石酸 氯化钾微波消解样品 ,ICP AES法连续测定粗氧锑中Hg和As的含量。测定粗氧锑的相对偏差 (RSD) :Hg为 0 87%～ 3 2 % ,As为 1 3%～ 2 9% ;回收率 :90 %～ 10 7%     

用FAAS法测定铅电解液中的铜和银

本文采用原子吸收法测定铅电争液中的Ｃｕ和Ａｇ。Ｃｕ的相对标准偏差为５．１％,Ａｇ的相对标准偏差为４．２％,方法简单,回收率在９６．７％－１０６．７％之间。     

铝锂合金样品的前处理及其Ag和Li的光谱分析

针对铝锂合金样品检测其Ag和Li,采用等离子体原子发射光谱法(ICP-OES)同时测定Ag和Li,火焰原子吸收光谱法(FAAS)分别测定Ag和Li,单宁酸分光光度法(VS)测Ag,对不同的光谱测定方法进行了比较,证明了ICP-OES检测铝锂合金中的Ag和Li具有较高的抗干扰性。对比了三种不同的样品消解方法,确定了FAAS测Li采用王水溶样最佳,ICP-OES,FAAS和VS测Ag采用HCl+H₂O₂体系溶样准确度更高。详细讨论了样品中共存元素Al, Mg, Zr, Ti, Cu的干扰及消除方法。用氨水沉淀消除共存元素Al,Ti,Zr,8-羟基喹啉沉淀分离Mg和Cu的方法消除原子吸收光度法测Ag的干扰;采用磷酸盐沉淀分离Ti而消除原子吸收光度法测Li的干扰;采用与原子吸收光度法测银相同的消除干扰方法,消除上述离子干扰,滤去干扰沉淀后,用硝酸赶盐酸解蔽Ag+离子,同时分解消除8-羟基喹啉的颜色,以消除分光光度法测银的干扰。对比消除干扰前后的结果发现准确度显著提高,证明消除干扰的方法切实有效。将选择的最佳消解体系和干扰消除方法应用于铝锂合金样品的测定,ICP-OES测Li和Ag回收率分别在100.39%～103.01%和100.42%～103.73%之间,FAAS测Li和Ag 回收率分别在95.91% ～99.98%和98.04%～103.67%之间,分光光度法测Ag回收率在98.00%～101.00%之间,测定结果满足分析要求。     

Technical evaluation of in vivo abdominal fat and IMCL quantification using MRI and MRSI at 3 T

OBJECTIVES: The objectives of this study were to develop protocols that measure abdominal fat and calf muscle lipids with magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS), respectively, at 3 T and to examine the correlation between these parameters and insulin sensitivity. MATERIALS AND METHODS: Ten nondiabetic subjects [five insulin-sensitive (IS) subjects and five insulin-resistant (IR) subjects] were scanned at 3 T. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were segmented semiautomatically from abdominal imaging. Intramyocellular lipids (IMCL) in calf muscles were quantified with single-voxel MRS in both soleus and tibialis anterior muscles and with magnetic resonance spectroscopic imaging (MRSI). RESULTS: The average coefficient of variation (CV) of VAT/(VAT+SAT) was 5.2%. The interoperator CV was 1.1% and 5.3% for SAT and VAT estimates, respectively. The CV of IMCL was 13.7% in soleus, 11.9% in tibialis anterior and 2.9% with MRSI. IMCL based on MRSI (3.8+/-1.2%) were significantly inversely correlated with glucose disposal rate, as measured by a hyperinsulinemic-euglycemic clamp. VAT volume correlated significantly with IMCL. IMCL based on MRSI for IR subjects was significantly greater than that for IS subjects (4.5+/-0.9% vs. 2.8+/-0.5%, P=.02). CONCLUSION: MRI and MRS techniques provide a robust noninvasive measurement of abdominal fat and muscle IMCL, which are correlated with insulin action in humans.     

对氯甲苯和对氯苯甲醛的气相色谱法分离分析

建立了用气相色谱同时测定对氯甲苯和对氯苯甲醛的方法.选用HP-INNOWAX毛细管色谱柱,以氯苯为内标物,在选定的色谱条件下,反应物对氯甲苯和产物对氯苯甲醛均有较广的线性范围,测定结果标准偏差均为0.44%,相对标准偏差分别为0.59%和1.69%.该方法快速、简便,重复性较好,适用于常规的检测分析.     

Structural and Metabolic Pattern Classification for Detection of Glioblastoma Recurrence and Treatment-Related Effects

Artificial neuronal network (ANN) in classification of glioblastoma multiforme (GBM) recurrence from treatment effects using advanced magnetic resonance imaging techniques was evaluated. In 56 patients with treated GBM, normalised minimal and mean apparent-diffusion coefficient (ADC) values, vessels number on susceptibility-weighted images (SWI) and Cho/Cr ratio were analysed statistically and by ANN. Significant correlation exists between normalised minimal and mean ADC values, and no correlation between ADC and Cho/Cr values. Cut-off values for tumour presence were: 1.14 for normalised minimal ADC (54% sensitivity, 71% specificity), 1.13 for normalised mean ADC (51% sensitivity, 71% specificity), 1.8 for Cho/Cr ratio (92% sensitivity, 82% specificity), grade 2 for SWI (87% sensitivity, 82% specificity). An accurate prediction of ANN to classify patients into GBM progression or treatment effects group was 99% during the training and 96.8% during the testing phase. Multi-parametric ANN allows distinction between GBM recurrence and treatment effects, and can be used in clinical practice.     

Clinical applications: MRI, SPECT, and PET

MRI, PET, and SPECT are all used to image abnormalities in the epileptic brain. Comparison of the techniques is difficult because they measure different aspects of the epileptic process—structure, metabolism, and perfusion. SPECT is the only one that can be systematically applied during seizures, while all three are used to image interictal abnormalities. Literature review suggests that of interictal techniques, PET has the highest diagnostic sensitivity in temporal lobe epilepsy (TLE) (84% vs. 66% for SPECT, 55% for qualitative MRI, 71% for quantitative MRI) while SPECT has the highest sensitivity in extratemporal epilepsy (ETE) (60% vs. 43% for MRI and 33% for PET). The highest diagnostic sensitivity and specificity were achieved by ictal imaging with SPECT (90% in TLE, 81% in ETE). The techniques, however, were not always redundant. One reason for the wide discrepancy of results in TLE and ETE might be the differing pathologic substrates. A literature review of imaging findings associated with mesial temporal sclerosis (MTS), developmental lesion or tumor as the underlying abnormality associated with epilepsy supports this explantion. PET and MRI are much more sensitive to MTS than SPECT (100%, 95% vs. 70%). On the other hand, in developmental lesions the three techniques are equally sensitive (88–92%) and in tumors, MRI was most sensitive (96%) and SPECT least (82%). A study at NIH explains the differing sensitivities: using PET to measure both blood flow and metabolism revealed discrepant findings in the same patients. Preliminary evidence also indicates that the distribution of hyperperfusion on ictal SPECT can differentiate subtypes of TLE. Combining the results of refined imaging techniques holds great promise in epilepsy localization and diagnosis.