石墨炉原子吸收光谱法测定一次性输液器中的痕量镉

目的建立石墨炉原子吸收光谱法(GFAAS)测定一次性输液器中微量镉的方法。方法以NH4H2PO4为基体改进剂,石墨炉原子吸收光谱法测定一次性输液器中的镉。结果在优化实验条件下,方法的检出限为,精密度为,试样回收率为。结论石墨炉原子吸收法测定一次性输液器中的镉,是一种快速、灵敏、准确的分析方法。     

金银花药材中重金属铅、镉含量分析

目的测定五批金银花药材中重金属铅、镉含量。方法采用高压消解法处理样品,石墨炉原子吸收分光光度法测定了其铅、镉含量。结果五批药材均检出一定量的铅、镉,但含量较低,未超出国家限量标准,符合《中华人民共和国药典2005年版一部》金银花项下有关规定。结论该方法简便快速,灵敏度高,能够用来分析金银花药材中重金属铅、镉含量。     

石墨炉原子吸收分光光度法测定阿莫西林胶囊中微量铅、镉的含量

目的:建立测定阿莫西林胶囊中微量铅、镉的方法。方法:采用石墨炉原子吸收分光光度法。检测波长铅为283.3nm,镉为228.8nm;灯电流为2.0mA;狭缝宽度为0.4nm。结果:铅浓度在0～10.0ng·mL-1、镉浓度在0～0.5ng·mL-1范围内与吸光度呈良好线性关系;平均加样回收率分别为98.0%(RSD=1.0%,n=9)、97.8%(RSD=0.99%,n=9)。结论:石墨炉原子吸收分光光度法测定阿莫西林胶囊中微量铅、镉,方法准确、简单、灵敏,被测溶液稳定性好。     

石墨炉原子吸收分光光度法测定维生素C原料中微量铅、镉含量

目的 建立石墨炉原子吸收分光光度法测定维生素C原料中微量铅、镉的分析方法.方法 检测波长铅为283.3 nm、镉为228.8 nm,灯电流为2.0 mA,狭缝宽度为0.4 nm.结果 铅质量浓度在0.0~10.0 ng/mL、镉质量浓度在0.0~0.5 ng/mL范围内与吸光度呈较好的线性关系,平均加样回收率分别为98.6%和97.8%,RSD分别为1.1%和1.5%(n=9).结论 石墨炉原子吸收分光光度法测定维生素C原料中微量铅、镉,方法准确、简单、灵敏,被测溶液稳定性好.     

石墨炉原子吸收分光光度法测定冰片中微量铅镉铜

目的:建立石墨炉原子吸收分光光度法测定冰片中微量铅、镉、铜的分析方法.方法:检查波长铅为283.3 nm,镉为228.8nm,铜为324.7 nm;灯电流为10.0 mA;狭缝宽度为0.4 nm.结果:铅在0.0～40.0 ng/mL、镉在0.0～1.0 ng/mL、铜在0～10 ng/mL范围内有较好的线性关系,平均加样回收率分别为98.3％,98.0％,97.3％.结论:石墨炉原子吸收分光光度法测定冰片中微量铅、镉、铜,方法准确、简单、灵敏,被测溶液稳定性好.     

石墨炉原子吸收分光光度法检测双黄连注射液中镉元素的含量

目的：建立石墨炉原子吸收分光光度法测定双黄连注射液中镉元素的含量。方法：采用微波消解系统消解样品,以石墨炉原子吸收分光光度法测定双黄连注射液中镉元素的含量．结果：线性范围为0—8．0μg·L^-1,一次方程相关系数r为0．9989。结论：采用本方法检测双黄连注射液中镉元素的含量,方法灵敏、准确、可靠,对控制注射液中镉元素的含量有实际意义。     

石墨炉原子吸收分光光度法测定葛根芩连片中铅、镉、铜、锰的含量

目的:建立石墨炉原子吸收分光光度法测定葛根芩连片中铅、镉、铜、锰的含量.方法:采用硝酸和高氯酸(2:1,v/v)消解样品,用石墨炉原子吸收分光光度法测定铅、镉、铜、锰的含量.结果:各元素的方法回收率在98.4%～99.0%之间,RSD在1.0%～1.2%之间.结论:该方法准确、可靠,适用于葛根芩连片中铅、镉、铜、锰的含量测定.     

麻雀体内铅和镉残留量的测定

目的探讨石墨炉原子吸收光谱法测定生物体内铅和镉残留量的可行性。方法用石墨炉原子吸收光谱法测定夏季哈尔滨市区内麻雀心脏、胸肌、肝脏、初级飞羽四种组织内铅和镉两种金属元素的残留量。结果麻雀体内铅和镉的残留量均为初级飞羽内最高。麻雀的初级飞羽和其他三种组织之间,铅和镉的残留量均存在明显的正相关。结论环境中铅和镉的变化对麻雀有明显的影响。     

石墨炉原子吸收法测定食品中铅的分析

食品中铅的测定有石墨炉原子吸收法、火焰原子吸收法、比色法、原子荧光法以及近几年来发展起来的ICP-MS法。其中石墨炉原子吸收法灵敏度高,适合于食品中微量铅的测定。但石墨炉原子吸收法重现性稍差,为了提高其重现性,本文对铅的石墨炉原子吸收法的测定条件及影响因素进行研究,确定了仪器的最佳工作条件。     

石墨炉原子吸收分光光度法测定阿胶当归胶囊内容物铬的含量

目的 建立石墨炉原子吸收分光光度法测定阿胶当归胶囊中微量铬的分析方法.方法 检测波长为357.9nm;灯电流为4.0mA;狭缝宽度为0.4nm.结果 铬进样量在0.0～0.40ng范围内吸收度与进样量呈较好的线性关系,平均加样回收率为99.1%.结论 石墨炉原子吸收分光光度法测定阿胶当归胶囊中微量铬,方法准确、简单、灵敏,被测溶液稳定性好.     

Temperature dependency of cadmium uptake and relaxant effect of cadmium in guinea-pig taenia coli

Cadmium fluxes were studied under low temperature in order to assess the site of action of Cd2+ in taenia coli. Following a treatment with 0.5 mM Cd2+ for 30 min at 37 degrees C, the responses to high-K+ were not reversed after washing with medium containing 0.5 mM disodium edetate (EDTA). However, at 30 min preincubation with 0.5 mM Cd2+ at 4 degrees C, the responses markedly returned by the washing. The cadmium uptake was much slower at 4 degrees C. The cadmium in muscle preincubated at 4 degrees C was markedly eliminated by EDTA. Thus, the increase in the size of the fraction of total cadmium not eliminated by EDTA was temperature dependent. These data suggest the possibility that the total cadmium not eliminated by EDTA in taenia coli may be accumulated in the intracellular compartment where EDTA cannot reach.     

Temperature-dependent stress response in oysters, Crassostrea virginica: pollution reduces temperature tolerance in oysters

Combined effects of temperature and a toxic metal, cadmium (Cd), on energy metabolism were studied in a model marine bivalve, the eastern oyster Crassostrea virginica, acclimated at 20, 24 and 28 degrees C and exposed to 50microgl(-1) of Cd. Both increasing temperature and Cd exposure led to a rise in standard metabolic rates, and combined stressors appeared to override the capability for aerobic energy production resulting in impaired stress tolerance. Oysters exposed to elevated temperature but not Cd showed no significant change in condition, survival rate and lipid peroxidation, whereas those exposed to both Cd and temperature stress suffered high mortality accompanied by low condition index and elevated lipid peroxidation. Furthermore, RNA/DNA ratios indicative of protein synthesis rate, and levels of glutathione, which is involved in metal detoxification, increased in Cd-exposed oysters at 20 degrees C but not at 28 degrees C. Implications of the synergism between elevated temperatures and cadmium stress on energy metabolism of oysters are discussed in the light of the potential effects of climate change on oyster populations in polluted areas.     

The potential for adaptation in a natural Daphnia magna population: broad and narrow-sense heritability of net reproductive rate under Cd stress at two temperatures

The existence of genetic variability is a key element of the adaptive potential of a natural population to stress. In this study we estimated the additive and non-additive components of the genetic variability of net reproductive rate (R(0)) in a natural Daphnia magna population exposed to Cd stress at two different temperatures. To this end, life-table experiments were conducted with 20 parental and 39 offspring clonal lineages following a 2?×?2 design with Cd concentration (control vs. 3.7?μg Cd/L) and temperature (20 vs. 24?°C) as factors. Offspring lineages were obtained through inter-clonal crossing of the different parental lineages. The population mean, additive and non-additive genetic components of variation in each treatment were estimated by fitting an Animal Model to the observed R(0) values using restricted maximum likelihood estimation. From those estimates broad-sense heritabilities (H(2)), narrow-sense heritabilities (h(2)), total (CV(G)) and additive genetic coefficients of variation (CV(A)) of R(0) were calculated. The exposure to Cd imposed a considerable level of stress to the population, as shown by the fact that the population mean of R(0) exposed to Cd was significantly lower than in the control at the corresponding temperature, i.e. by 23?% at 20?°C and by 88?% at 24?°C. The latter difference indicates that increasing temperature increased the stress level imposed by Cd. The H2 and CV(G) were significantly greater than 0 in all treatments, suggesting that there is a considerable degree of genetic determination of R(0) in this population and that clonal selection could rapidly lead to increasing population mean fitness under all investigated conditions. More specifically, the H2 was 0.392 at 20?°C+Cd and 0.563 at 24?°C+Cd; the CV(G) was 30.0?% at 20?°C+Cd and was significantly higher (147.6?%) in the 24?°C+Cd treatment. Significant values of h(2) (=?0.23) and CV(A) (=?89.7?%) were only found in the 24?°C+Cd treatment, suggesting that the ability to produce more offspring under this stressful condition may be inherited across sexual generations. In contrast, in the less stressful 20?°C+Cd treatment the h(2) (0.06) and CV(A) (7.0?%) were very low and not significantly higher than zero. Collectively our data indicate that both the asexual and sexual reproduction phases in cyclic parthenogenetic D. magna populations may play a role in the long-term adaptive potential of Daphnia populations to chemical stress (with Cd as the current example) and that environmental variables which influence the stress level of that chemical may influence this adaptive potential (with temperature as current example).     

Cadmium induced hypothermia in mice: dose dependent tolerance development

The i.p. injection of Cd in mice will produce a dose related hypothermic response. The Cd appears to make the animals poikilothermic and their body temperature will approach the ambient temperature at which they are housed. The cause for this hypothermic action of Cd is not known, but we have demonstrated in our experiments that the effect may be partially related to a direct effect within the brain. In addition, the repeated injection of a low Cd dose (0.62 mg/kg) i.p. once daily for 3 days results in a profound tolerance to the Cd. A high dose (1.25 mg/kg i.p. once daily X 3 days) of Cd did not result in a similar tolerance phenomenon and a single injection of the high Cd dose 120 hr prior to the repeated low Cd dose regimen resulted in an obtunded tolerance response to the low dose. We propose that the higher Cd dose may have damaged the blood-brain barrier and this could account for the results we have observed.     

Axonal transport of cadmium in the olfactory nerve of the pike.

109Cd2+ was applied in the olfactory chambers of pikes (Esox lucius) and the dynamics of the axoplasmic flow of the metal was determined in the olfactory nerves by gamma spectrometry and autoradiography. The results showed that the 109Cd2+ is transported at a constant rate along the olfactory nerves. The profile of the 109Cd2+ in the nerves showed a wave front of transported metal followed by a saddle region. When the nasal chambers were washed 2 hr after application of the 109Cd2+ well-defined transport peaks for the metal were seen in the olfactory axons. The maximal velocity for the transport of 109Cd2+, which corresponds to the movement of the wave front, was 2.38 +/- 0.10 mm/hr (mean +/- S.E.) at the experimental temperature (10 degrees C). The average velocity for the transport of the 109Cd2+, which corresponds to the peak apex movement of the wave, was 2.18 +/- 0.05 mm/hr (mean +/- S.E.) at 10 degrees C. The transported 109Cd2+ was strongly accumulated in the anterior parts of the olfactory bulbs, whereas in other brain areas the levels of the metal remained low. Autoradiography of a pike exposed to 109Cd2+ via the water showed a strong labelling in the receptor-cell-containing olfactory rosettes, whereas other structures in the olfactory chambers were only weakly labelled. The accumulation and axonal transport in the olfactory neurons may be noxious and constitute an important component in the toxicology of cadmium in fish, and this may apply also to some other heavy metals.     

Quality assessment of trace Cd and Pb contaminants in Thai herbal medicines using ultrasound-assisted digestion prior to flame atomic absorption spectrometry

A simple, efficient, and reliable ultrasound-assisted digestion (UAD) procedure was used for sample preparation prior to quantitative determination of trace Cd and Pb contaminants in herbal medicines using flame atomic absorption spectrometry. The parameters influencing UAD such as the solvent system, sample mass, presonication time, sonication time, and digestion temperature were evaluated. The efficiency of the proposed UAD procedure was evaluated by comparing with conventional acid digestion (CAD) procedure. Under the optimum conditions, linear calibration graphs in a range of 2–250 μg/L for Cd, and 50–1000 μg/L for Pb were obtained with detection limits of 0.56 μg/L and 10.7 μg/L for Cd and Pb, respectively. The limit of quantification for Cd and Pb were 1.87 μg/L and 40.3 μg/L, respectively. The repeatability for analysis of 10 μg/L for Cd and 100 μg/L for Pb was 2.3% and 2.6%, respectively. The accuracy of the proposed method was evaluated by rice flour certified reference materials. The proposed method was successfully applied for analysis of trace Cd and Pb in samples of various types of medicinal plant and traditional medicine consumed in Thailand. Most herbal medicine samples were not contaminated with Cd or Pb. The contaminant levels for both metals were still lower than the maximum permissible levels of elements in medicinal plant materials and finished herbal products sets by the Ministry of Public Health of Thailand. The exception was the high level of Cd contamination found in two samples of processed medicinal plants.     

Further analysis of cadmium uptake from apical membrane of LLC-PK1 cells via inorganic anion exchanger

This study was undertaken to analyze Cd uptake via the inorganic anion exchanger (HCO3-/Cl-) by LLC-PK1 cells cultured on permeable membranes. LLC-PK1 cells were incubated at 37 degrees with 1 microM CdCl2 added to the apical medium, and Cd accumulation in the cells was fractionated into a membrane-bound (non-internalized) Cd fraction and an internalized Cd fraction using ethyleneglycol-bis-(beta-aminoethylether)-N,N,N',N'-tetraace tic acid (EGTA), a chelating agent for Cd. Incubation at a lower temperature (4 degrees) significantly decreased the membrane-bound Cd fraction, and drastically decreased the internalized Cd fraction. Addition of NaHCO3 (a stimulator of Cd uptake via inorganic anion exchanger) to the apical medium significantly increased both membrane-bound and internalized Cd fractions, and this increase was greater for the internalized fraction. Pretreatment of cells with 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), a specific inhibitor of inorganic anion exchangers, significantly decreased the internalized Cd fraction without changing the membrane-bound Cd fraction. Addition of NaHCO3 did not effect both Cd fractions in DIDS-pretreated cells. These results suggest that most of Cd binds non-specifically to the apical membrane surface and then is internalized via simple diffusion and some Cd specifically binds to the inorganic anion exchanger and is internalized in a metabolism-dependent manner.     

基于EST-SSR的金银花分子鉴别方法研究

利用简单有效的方法鉴定药用植物种及其变种一直是中药材鉴定首先要解决的问题。金银花是临床常用大宗中药材之一,源自忍冬科植物忍冬(Lonicera japonica Thunb.)的花蕾。为了有效利用金银花EST序列开发功能性分子标记,本文通过生物信息学手段对本实验室保存的忍冬及其变种红白忍冬(L.japonica var.chinensis Thunb.)EST序列进行分析,共获得3 705条忍冬EST-SSRs,且平均每4.05 kb检出一个SSR(simple sequence repeat);2 818条红白忍冬EST-SSRs,平均每7.49 kb检出一个SSR。分析结果表明金银花及其变种红白忍冬主要SSR重复为二核苷酸,其次为三核苷酸,主要重复基序类型为AG/TC和GAG/TCT。通过同源比对,在忍冬及其变种中共筛选出87对重复次数具有差异的EST-SSR。选出15对碱基数差异大于6的EST-SSR进行验证,结果表明其中的13对引物在52份金银花类药用植物中具有有效扩增产物,且引物jp.ssr4、jp.ssr64及jp.ssr65可用于忍冬及其变种、山银花原植物的鉴别。     

Different transport mechanisms for cadmium and mercury in Caco-2 cells: inhibition of Cd uptake by Hg without evidence for reciprocal effects

Cadmium/Hg interactions have been studied in the TC7 clone of the enterocytic-like Caco-2 cells to test the hypothesis that these metals may compete for intestinal transport. Comparison of the kinetic parameter values for 203Hg(II) and 109Cd(II) uptake in a serum-free medium revealed that Hg is accumulated much more rapidly and to higher concentrations. The very rapid uptake/binding step and the initial uptake rate of 109Cd were both significantly inhibited by an excess of unlabeled Cd or Hg (apparent K(i) for Hg of 9.3 +/- 1.2 microM) without reciprocal effects. 109cadmium uptake was highly sensitive to temperature and a significant fraction of accumulation (12%) was EDTA extractable. 203Hg uptake remained insensitive to temperature or the EDTA washing procedure. However, the uptake of both tracers was half-decreased when an excess of the respective unlabeled metal was added in the stop solution, suggesting an exchange mechanism for adsorption. Cell pretreatment with N-ethylmaleimide (NEM) led to a 30% decrease or a 73% increase in the 3-min specific transport of 109Cd when NEM was still present in or removed from the uptake medium, respectively. NEM had no effect on 203Hg uptake. Overall our results suggest the involvement of a saturable specific mechanism for Cd, which is highly sensitive to inhibition by Hg and NEM under some conditions, and a nonspecific passive diffusion for Hg. The Hg- or NEM-induced inhibition of Cd uptake likely involves a thiol-mediated reaction, but our results suggest that NEM pretreatment may activate other cellular mechanisms leading to a stimulatory effect.     

Use of Hsf1(-/-) mice reveals an essential role for HSF1 to protect lung against cadmium-induced injury

Cadmium (Cd) is known to activate heat shock (HS) response, which is characterized by overexpression of heat shock proteins (Hsps) under the control of heat shock factor 1 (HSF1). The potential protection provided by the HS response, induced by increasing the body temperature of animals before Cd exposure or by Cd itself, against pathophysiological changes occurring after Cd intranasal instillation (1 to 100 microg/mouse) was examined. HSF1-deficient mice were used to evaluate the role of this factor in lung protection. Cd instillation caused dose- and time-dependent changes in the respiratory pattern measured by plethysmography (Penh), and significant increases in lactate dehydrogenase (LDH) activity as well as macrophage and neutrophil counts in bronchoalveolar lavage fluids. HS preconditioning induced Hsp overexpression and reduced the Penh (-30%), LDH (-25%), and neutrophil (-55%) responses to subsequent administration of the highest Cd doses (50 and 100 microg) in wild-type mice. HSF1 deficiency abolished the HS response and its protective effect. In the absence of preconditioning, Hsf1(-/-) mice exhibited higher values of Penh (+70%) and LDH activity (+42%) compared with wild-type animals when exposed to the lowest Cd doses. Higher macrophage (+80%) and neutrophil counts (+115%) were recorded whatever the dose. Western blot analyses indicated that lung protection might be related to the kinetics of HSF1-dependent Hsp70 expression. Altogether, our data demonstrate that HS response elicited both by prior HS and by Cd itself moderates pulmonary injuries due to Cd instillation, and that HSF1 is a major mediator in this protection.