The determination of mercury in biological objects on a mercury hydride attachment to the AAS-30 atomic absorption spectrophotometer]

Tuberculosis of the large bronchi (TLB) was diagnosed by rigid bronchoscopy (RBS) in 9.4% and by fibrobronchoscopy (FBS) in 18.3% of patients. Such great differences are attributable to the extension of a visualization area during FBS than during RBS. Analyzing the specimens obtained at bronchoalveolar lavage and other types of biopsy of TLB areas cytologically and histologically confirmed the visual picture in 63.4% of cases.     

原子荧光光谱法测定化探样品中痕量汞

提出了以震荡水浴—聚乙烯膜封闭溶矿、氢化物发生—原子荧光光谱法测定化探样品中汞的分析方法。对溶矿方式、灯电流、载气、屏蔽气流速及硼氢化钾浓度进行了优化选择。在最佳条件下,建立了汞的校准曲线,其相关系数在0.999 1～0.999 3之间,方法检出限为0.125 ng/g。将本方法应用于化探标准样品和实际样品分析,所得结果与认定值或封闭溶样两次金汞齐冷原子吸收光谱法测得值一致,5次平行测定结果的相对标准偏差不大于3.5%。     

Factors affecting the determination of total mercury in biological samples by continuous-flow cold vapor atomic absorption spectrophotometry

The acidic reduction of Hg using a continuous-flow analytical system was evaluated. With 25% SnCl2 as the reductant, characteristic concentrations (sensitivities) of 0.44 microgram/L (open cell) and 0.29 microgram/L (flow-through cell) were obtained using inorganic Hg2+ standards in 1.5% HCl. When CH3Hg+ standards were used, absorption signals were an order of magnitude lower, indicating that Sn(II) is incapable of producing Hg degree from organic Hg in this acidic reduction system. Addition of CdCl2 to the SnCl2 reductant, as suggested by Magos (1) for the reduction of organomercurials under alkaline conditions, was without beneficial effect. Similarly, combining Sn with another reducing agent (hydroxylamine hydrochloride), or a strong alkaline solution (40% NaOH), in the reaction coil of the flow-through system did not significantly enhance the Hg absorption signal for either inorganic or organic Hg. Recovery of Hg from spiked liver homogenates digested at 70-80 degrees C using a HNO3/H2SO4/HCl procedure and stabilized with 0.5 mM K2Cr2O7 was > 85% using either inorganic Hg2+ or CH3Hg+, indicating that this digestion procedure successfully breaks the C-Hg bond to form readily reducible Hg species. Using L-cysteine to stabilize standards of inorganic Hg2+ in HCl caused significant depressions of the Hg absorption signal at L-cysteine concentrations > 0.001% (approximately 0.5 mM); 0.1% L-cysteine caused total suppression of the Hg signal. These results indicate that: (1) acidic reduction of Hg by Sn in this continuous-flow system requires breakdown of organomercurials prior to analysis; (2) tissue digestion using HNO3/H2SO4/HCl followed by the addition of K2Cr2O7 to stabilize Hg2+ achieves this breakdown and allows good recovery of total Hg; and (3) use of L-cysteine to complex and prevent losses of Hg should be avoided in systems using acidic reduction of Hg. Concentrations of endogenous tissue sulfhydryls are generally lower than those associated with depressed absorbance signals during the acidic reduction of Hg.     

水杨基荧光酮荧光猝灭法测定钼原矿中钼

钼的加入会使水杨基荧光酮(SAF)的荧光发生猝灭, 且猝灭的程度与钼的浓度呈线性关系, 据此建立了钼原矿中低含量钼的测定方法。实验选用4.0 mL 1.0% OP和1.0%吐温-80体积比为0.8∶0.2的混合溶液进行增敏, 加入2.0 mL 1.0×10^-3 mol/L SAF溶液, 2.0 mL 0.1 mol/L HCl, 在常温下反应30 min后于λ_ex/λ_em =460/520 nm处测定荧光发射强度, 结果表明, 钼浓度在 0.013~0.20 μg/mL范围之内与ΔF呈线性关系, 线性方程为ΔF=2 865.0ρ－10.667, 相关系数(R²)为0.998 8, 方法检出限为0.013 μg/mL。方法应用于测定钼原矿企业管理样中低含量的钼, 结果与参考值一致, 相对标准偏差为1.1%～1.8%, 回收率为93%～113%。     

顺序注射氢化物发生-原子荧光光谱法同时测定环境水样中铋和汞

建立了一种顺序注射氢化物发生-原子荧光光谱法同时测定水样中的Bi和Hg含量的方法。考察了光电倍增管负高压、铋和汞灯电流、原子化器高度、载气流量、屏蔽气流量等因素对测定结果的的影响。研究发现:载流HCl的浓度为0.3~0.6 mol/L,KBH4浓度为4 g/L,稳定剂K2Cr2O7浓度为5 g/L时,同时测定铋和汞的效果最佳。在最佳实验条件下,铋和汞的检出限分别为0.005 8μg/L和0.007 5μg/L。方法用于河水、井水和池水水样中铋和汞的测定,加标回收率为91.0%~109%,相对标准偏差小于3.4%,被测水样中共存的离子对铋和汞的测定没有干扰。     

Determination of N,N',N"-triethylenthiophosphoramide in biological samples using capillary gas chromatography

A sensitive assay for the determination of N,N',N"-triethylenthiophosphoramide (thioTEPA) in microvolumes of human plasma and urine has been developed. ThioTEPA was analysed using gas chromatography with selective nitrogen-phosphorus detection, after extraction with ethyl acetate from the biological matrix. Diphenylamine is the internal standard. The limit of quantitation was 0.1 ng/ml, using only 100 microl of sample; recoveries ranged between 85 and 100% and both accuracy and precision were less than 10%. Using a flame ionisation nitrogen-phosphorus detector, the assay was not linear over the concentration range of 2-1000 ng/ml for plasma and 10-1000 ng/ml for urine. Linearity was accomplished in the range of 1-1000 ng/ml for plasma and urine when a thermionic nitrogen/phosphorous detector was used. The stability of thioTEPA in plasma proved to be satisfactory over a period of 3 months, when kept at -20 degrees C, whereas it was stable in urine for at least 1 month at -80 degrees C. ThioTEPA plasma concentrations of two patients treated with thioTEPA are presented demonstrating the applicability of the assay.     

EDTA差减滴定法测定汞污染土壤中汞

提出了快速测定汞污染土壤中汞含量的EDTA差减滴定法。土壤样品用H3PO4和H2SO4混合酸溶解,用焦磷酸钠掩蔽Cu2+,调至pH5～6,以二甲酚橙为指示剂,用EDTA标准溶液滴定溶液中能与EDTA络合的全部金属离子的总量;然后在另一份相同试液中,先加入硫脲掩蔽Hg2+,再用EDTA标准溶液滴定除汞外的其它金属离子,利用二者之差计算汞的含量。改进后的方法,简单、快捷、干扰小,测定结果与国家标准方法一致,相对标准偏差小于2.0%,加标回收率在97.2%～100.1%之间。     

过氧化钠熔融-硫氰酸铵差示光度法测定钼精矿和钼焙砂中钼

研究了用过氧化钠在高铝坩埚中700 ℃熔融样品5～10 min,用硫氰酸铵差示光度法测定了钼精矿和钼焙砂中钼含量的方法。对样品的熔融条件、样品溶液的制备条件和测定条件进行了优化。通过加入无水乙醇消除了MnO^2-₄的干扰,采用三氯化铁溶液沉淀吸附和酒石酸钠掩蔽的方式消除了钨(Ⅵ)、铬(Ⅵ)和钒(Ⅴ)等其它共存离子的影响。结果表明,于吸收波长λ=480 nm处,钼质量浓度在14.0～26.0 μg/mL范围内符合比尔定律,检出限为4.2×10^-2 μg/mL。将本法用于钼精矿管理样品GLY-01、钼精矿和钼焙砂生产样品中钼的测定,测定值与参考值或重量法测得结果一致,相对标准偏差(RSD,n=11)为0.10%～0.14%。     

Determination of organophosphorous pesticides in biological samples of acute poisoning by HPLC with diode-array detector

We have studied fibrinogen levels (Clauss technique) in atherothrombotic ischemic stroke patients, in order to determine its role as a thrombogenic risk factor. Twenty nine patients (20 men and 9 women) between 25 and 79 years old were studied; they all have had a atherothrombotic stroke. They were classified into two groups according to the result of their carotid doppler ultrasonography: gl-without carotid flow reduction (n = 19) and g2-with carotid flow reduction (n = 10). The fibrinogen mean value was 269 mg/dl in gl and 353 mg/dl in g2. There were 47% of patients in gl and 80% of patients in g2 who presented levels > 300 mg/dl. The proportions of the groups were significantly different (p < 0.05). Considering the epidemiological value of 300 mg/dl, we conclude that the fibrinogen can be an independent risk factor for ischemic atherothrombotic stroke, specially in those whose carotid flow is reduced.     

ICP—AES法测定钼精矿中的金

研究了电感耦合等离子体发射光谱（[CP—AES）法对钼精矿中金的分析测定。样品采用N3,·H2O分离、王水溶解、泡沫塑料富集、ICP—AES法测定,对仪器分析测试条件及方法的精密度、检出限作了相应的讨论,进行了实验室之间对比实验和测定方法对比实验。通过实验研究表明,该方法准确、可靠,测定结果令人满意。     

亚甲基蓝-高碘酸钾催化动力学光度法测定钼尾矿中钼

实验研究发现,在硫酸存在的情况下,高碘酸钾可以氧化亚甲基蓝褪色,钼对该褪色反应有催化作用,据此,建立了催化动力学光度法测定钼尾矿中钼的新方法。实验表明:当显色体系中亚甲基蓝浓度为0.012 g/L、硫酸浓度为0.001 mol/L、高碘酸钾浓度为0.000 4 mol/L时,于60 ℃加热13 min,钼在0.02～0.6 mg/L范围内与吸光度变化值呈良好的线性关系,方法检出限为0.05 mg/L。在最佳实验条件下,催化体系的表观活化能E_a=47.31 kJ/moL,反应速率常数k=3.5×10^-4/s。方法应用于3个不同地区钼尾矿中钼的测定,测定结果与原子吸收光谱法(AAS)吻合,相对标准偏差(RSD,n=11)为2.1%～2.9%,回收率为97%～102%。     

Determination of aldehydes and other lipid peroxidation products in biological samples by gas chromatography-mass spectrometry

The extremely broad spectrum of the biological effects of aldehydic lipid peroxidation products has necessitated the development of a technique that can quantitate all of the aldehydes formed in biological materials. The proposed method is based on the use of O-(2, 3, 4, 5, 6-pentafluorobenzyl) hydroxylamine hydrochloride (PFBHA.HCl) to form the O-pentafluorobenzyl-oxime (PFB-oxime) derivatives of 22 saturated and unsaturated aldehydes (C2-C12) including hexanal, 4-hydroxy-non-2-enal (HNE), and malondialdehyde (MDA), followed by trimethylsilylation of the hydroxyl group to trimethylsilyl (TMS) ethers. The PFB-oxime-TMS derivatives were analyzed by capillary column gas chromatography-negative-ion chemical ionization mass spectrometry (GC-NICIMS) with ammonia as reagent gas. Quantitation was achieved using benzaldehyde-ring-D5 as an internal standard in selected ion recording (SIR) mode. Standard curves were linear (r > 0.99) for all individual aldehydes. The detection limit was between 50 and 100 fmol per 1 microliter injected aldehyde. Recovery of all aldehydes from urine, plasma, and tissue homogenate was over 85%, except HNE, trans-2-octenal and trans-2,-cis-6-nonadienal from plasma and tissue sample, which were between 60 and 80%, suggesting these aldehydes may bind to protein and lipid components, especially to SH groups of proteins. The high sensitivity of this method allows the measurement of physiological aldehyde levels in biological samples. The products of aldehyde metabolism can also be measured by this assay.     

Determination of volume fraction in multiphase systems using incomplete pole figures

The determination of the volume fraction of a second phase in a multiphase sample by X-ray diffraction becomes more difficult if the diffracting planes have a preferred orien-tation. Lopata and Kula have described a method of treating this problem using complete pole figures for each of the phases. With some samples, it is not always possible or con-venient to obtain data over the full hemisphere. Equations and an example are given which require X-ray data over a limited range of approximately 0 to 75 deg. This can be ob-tained by reflection without a specially cut sample or transmission data. A series of Legendre polynomials are fitted to data collected while spinning the sample about its nor-mal. An extrapolation is made possible by introducing two conditions on the end points which must be satisfied if the extrapolation functions are to be valid.     

电感耦合等离子体原子发射光谱法测定碳化钼催化剂中钼

研究了电感耦合等离子原子发射光谱法测定碳化钼催化剂中钼的测定条件包括溶样酸、仪器参数、分析线和干扰的消除等,在此基础上建立了碳化钼催化剂中钼的测定方法。样品用 HNO₃、HF、HClO₄的混酸溶解处理后,在体积分数为2.5%的硝酸和1%氢氟酸混酸介质中,以Mo 202.030{166} nm 作为分析谱线,采用电感耦合等离子原子发射光谱法测定。通过筛选分析谱线、合理设置背景扣除位置,避免了光谱干扰。方法应用于碳化钼催化剂样品中钼的测定,结果与重量法(GB 50591-85)一致,相对标准偏差(n=6)小于1.5%,回收率在99%～100%之间。     

微波消解-分光光度法测定合金钢中钼

合金钢作为制造一些精密仪器和元件的重要原料,在现代社会生产、生活中起到不可替代的作用,而添加适量金属元素更使其保持卓越的性能。元素钼就是其中之一,它能增加钢的强度又不致于降低钢的可塑性和韧性,同时,又能使钢在高温下具有足够的强度,并可改善钢的冷脆性、耐磨性等性能。因此,测定合金钢中钼含量具有现实的意义。     

电感耦合等离子体质谱法测定地球化学样品中钼镉钨铀锡

在样品中依次加入HNO_3、HF、HClO_4、H_2SO_4,在电炉上于160℃加热1h,后升至240℃加热至白烟冒尽,180℃下再加入HNO_3复溶,以普通(STD)模式测定Cd,以动能歧视(KED)模式测定Mo、W、U、Sn,建立了电感耦合等离子体质谱法(ICP-MS)测定地球化学样品中Mo、Cd、W、U、Sn的方法。通过选用合适的同位素、测定模式和校正公式克服了质谱干扰;以10ng/mL~(187)Re和~(103)Rh为混合内标进行校正消除了基体效应和仪器信号的漂移。在优化的实验条件下,各元素校准曲线的线性相关系数均大于0.999,Mo、Cd、W、U、Sn检出限分别为0.068 9、0.002 0、0.092 6、0.123、0.089 6μg/g。按照实验方法对地球化学实际样品中Mo、Cd、W、U、Sn进行测定,测得结果的相对标准偏差(RSD,n=6)为2.4%~4.8%,回收率在91%~114%之间。将实验方法应用于水系沉积物、土壤、岩石标准物质中这5种元素的测定,结果与认定值相符。     

电感耦合等离子体质谱法测定钼矿石和钼精矿中铼

采用氧化镁焙烧样品,热水浸提后不需分离富集,电感耦合等离子体质谱法直接测定钼矿石及钼精矿中铼。对不同焙烧熔剂、焙烧条件、浸提条件以及仪器测定条件进行了研究,结果表明：以氧化镁为焙烧试剂,在650 ℃保温90 min,趁热用热水浸提为最佳溶样条件,测定时选用¹⁰³Rh为内标元素,可有效校正仪器漂移,减小基体效应的干扰。方法检出限为0.005 μg/g,回收率在94%~102%之间。本方法经国家标准物质分析验证,结果与认定值吻合,相对标准偏差（RSD,n=5）≤3.6%,适合钼矿石及钼精矿中含量为0.05~300 μg/g铼的测定。     

电感耦合等离子体原子发射光谱法测定钼矿石中的钨钼

运用过氧化钠碱熔法处理钼矿样, 直接以盐酸-柠檬酸-过氧化氢混合酸提取熔融物来避免硅胶的产生和钨酸、钼酸沉淀的生成。以W 207.912 nm和Mo 202.031 nm谱线作为钨、钼的分析线, Co 240.725 nm为内标线, 消除了基体干扰效应和仪器信号漂移的影响, 建立了电感耦合等离子体原子发射光谱法测定试液中钨和钼的方法。钨的检出限为0.010 μg/mL, 测定范围为0.013%～12.50%, 回收率为98%～102%;钼的检出限为0.005 μg/mL, 测定范围为0.006%～12.50%, 回收率为99%～102%。对钼标准矿样测试, 所测得钼、钨结果与认定值相符, 相对标准偏差(RSD, n=8)为1.2%~3.6%。     

Determination of trace levels of niguldipine in urine and blood by adsorptive stripping voltammetry at the hanging mercury drop electrode

Smyth line (SL) chickens spontaneously develop a posthatch autoimmune loss of pigment cells (vitiligo) in the feather. Concurrent with the development of Smyth line vitiligo (SLV), mononuclear cell infiltration and altered T cell profiles can be observed in the pulp of developing feathers. To determine whether the development of SLV is preceded by or associated with alterations in blood lymphocyte and leukocyte populations, blood leukocyte profiles were established at various times prior to and throughout the spontaneous development of SLV. The proportions among various blood leukocyte populations (percentage of lymphocytes, monocytes, heterophils, eosinophils, and basophils) were determined by immunofluorescence and flow cytometric analyses. Lymphocyte markers included fluorescence-conjugated monoclonal antibodies to identify T cells (CD3), T helper cells (CD4), cytotoxic T cells (CD8), and B cells (IgM). The proportions among blood lymphocyte populations examined did not differ between SL and MCH-matched parental Brown line (BL) control chickens prior to and throughout the development of SLV. Compared to BL controls, SL chickens had, however, increased proportions of inflammatory leukocytes in the blood, particularly at the time when most hatchmates developed SLV. Examination of leukocyte alterations with respect to first observation of SLV revealed that inflammatory leukocyte levels were elevated early in SLV. Although altered leukocyte profiles in the blood were observed during the development of SLV, blood from SL chickens did not reflect alterations in lymphocyte populations known to occur at the site of melanocyte destruction. The role of inflammatory blood leukocytes in the development of SLV needs to be further investigated.