茂名市水源、尿及食用盐碘含量的调查分析

为分析茂名地区居民膳食中碘摄入情况,给碘缺乏病防治提供依据,在所辖区域范围内,对居民饮用水水碘水平、8～10岁儿童尿碘水平、儿童家庭食用碘盐状况等进行了调查。结果表明,共监测27个镇水样128份,碘质量浓度在1.25～195.8μg/L之间,水碘中位值13.5μg/L。8～10岁儿童尿碘中位值为164μg/L,儿童家庭食盐含碘0～51.76 mg/kg,食盐碘与尿碘之间的关系出现不一致性。可见在非高碘地区,碘盐是影响人群营养的重要因素,盐碘应根据饮用水的碘含量而不同,在水碘小于20μg/L的地区盐碘在20～30 mg/kg比较适宜;在水碘为20～150μg/L的地区盐碘在10～20 mg/kg比较适宜。高碘地区应停供碘盐,改水降碘。     

缺碘区居民膳食结构及营养素摄入量对尿碘水平的影响

通过抽样调查,了解重庆市环境缺碘地区居民的饮食习惯,分析了膳食因素对人群尿碘水平的影响,为制订地方性碘缺乏病综合防治措施提供依据.采用24 h膳食回顾法,对重庆市两县居民的膳食摄人情况进行现况调查,比较各营养素摄入量.结果表明,两地膳食结构属于东方膳食模式,璧山县各营养素摄入量高于云阳县.结论:蛋白质、能量、维生素等缺...     

襄樊市学龄儿童碘营养现状调查

按东西南北中五个方位抽取了襄樊市７０所小学２８００名８－１０岁儿童进行了碘营养状况调查。以解诊和Ｂ超法检查甲状腺肿大率为主要指标,盐碘含量、尿碘水平为重要参考指标。结果表明：８－１０岁儿童甲肿率触诊法和Ｂ超法分别为１０．２５％和８．２５％,两者符合率为９６．６４％,甲肿率均超过５％,尿碘中位数为４３９．８１μｇ／Ｌ,尿碘值大于１００μｇ／Ｌ得占９６．６７％;儿童家中食盐含碘中位数为３１．３０＊１０     

科学补碘:消除碘缺乏病的成败关键

碘对甲状腺功能具有双向作用,在消除碘缺乏病的同时,切不可忽略全民食盐加碘后高碘甲状腺病的防治。分别从水碘和尿碘两个方面论述了碘与甲状腺病之间的双向关系,并根据流行病学调查数据和全国碘缺乏病监测数据确定了盐碘与尿碘之间的数学关系,计算了食盐碘含量的最适宜范围,提出了下调食盐碘含量、设计区域化碘盐和补碘个性化的科学补碘新策略。     

2005—2013年三水区居民食用碘盐监测情况分析

目的了解三水区居民食用碘盐情况。方法全区随机抽取约300份食用盐样。食盐碘含量按国标GB/T13025.7-1999(2012)中直接滴定法进行测定。结果 2005—2013年三水区碘盐覆盖率为96.76%;合格碘盐食用率为93.65%。结论合格碘盐食用率虽然达到国家标准要求90%以上,但仍有部分居民食用不合格碘盐,应进一步加强对碘盐的监督和管理,确保居民食用合格碘盐。     

孝感地区初诊甲状腺疾病患者尿碘水平分析

目的通过对孝感地区初诊甲状腺疾病患者的尿碘水平的检测,探讨尿碘水平与甲状腺疾病发生的相关性。方法选择孝感地区160例初诊甲状腺疾病患者作为观察组,同期选择60例健康体检者作为对照组,两组均采用砷铈催化分光光度计法测定尿碘含量,同时采用免疫化学发光法测定血甲状腺功能(FT3、FT4、TSH)及甲状腺抗体(TGAb、TMAb)水平,完善两组人群甲状腺彩色超声检查。结果 1两组尿碘中位数均100μg/L。2观察组尿碘中位数及平均值均明显高于对照组。3观察组中尿碘中位数及平均值均存在由高到低的以下规律:功能亢进组,功能正常组,功能减低组,显示尿碘越高,甲状腺功能水平越高。4观察组随着尿碘水平的增加,甲状腺体积逐渐增大(取肿大明显的单侧比较),但TGAb、TMAb组间比较无统计学差异。结论尿碘水平的升高是导致初诊甲状腺疾病患者甲状腺功能和形态改变的原因,其与甲状腺自身抗体无明显相关性。孝感地区人群食用普通碘盐后尿碘水平部分过量,需提倡科学补碘。     

基于四环素荧光熄灭测定碘的研究

基于碘对荧光试剂四环素的荧光熄灭,建立了测定微量碘的荧光分析方法。在pH10的碱性介质中,最大激发/发射波长分别为400.0nm/509.0nm,四环素的荧光强度与碘浓度的对数呈良好的线性关系,测定碘浓度的线性范围为3.20×10^-7～1.00×10^-4mol/L,检出限为1.30×10^-8mol/L,常见的共存离子不干扰测定。该方法适用于食盐中微量碘含量的测定。     

重庆地区特需人群碘营养水平及影响因素分析

为了解重庆地区孕妇、婴儿及其母亲碘营养现状,给该地区实施科学补碘提供科学依据,采用砷铈催化分光光度法测定了当地水碘和孕妇、婴儿及其母亲的尿碘,电化学发光法检查了孕妇甲状腺功能.结果表明,水碘为5.99 μg/L,孕妇、乳母、婴儿尿碘中位数为203.80 μg/L、218.3 μg/L、288.4 μg/L,FT3、FT4为(3.94±0.59) pmol/L、(12.44±2.30) pmol/L;逐步回归分析表明,碘营养与文化程度、食用优质蛋白及富硒食品呈正相关,母亲缺碘是小孩缺碘的危险因素之一.提示特需人群的碘营养水平适宜,文化程度、食用优质蛋白及富硒食品为主要影响因素,婴儿尿碘与母亲相关.     

顶空固相微萃取-气相色谱-质谱联用测定饮用水中的2-甲基异莰醇和土臭素

2-甲基异莰醇(2-methylisoborneol, 2-MIB)和土臭素(geosmin, GSM)在水源水中大量分泌排放是造成饮用水土霉异味突发事件、引发居民用水恐慌的重用因素之一。使用顶空固相微萃取(HS-SPME)与气相色谱-质谱联用技术(GC-MS)建立了水库水、水库附近土壤、居民自来水中2-MIB和GSM的测定方法。结合正交分析优化了加盐量、萃取温度、萃取时间条件,在电子轰击(EI)-选择离子扫描(SIM)模式下进行了目标物的定性定量分析。结果表明:在5~1000 ng/L范围内,2-MIB和GSM的色谱峰面积与其质量浓度的线性关系良好(r²≥0.998), 2-MIB与GSM的检出限分别为0.72 ng/L和0.34 ng/L,定量限分别为2.40 ng/L和1.13 ng/L;目标物加标水平为10~600 ng/L时,平均回收率为93.6%~107.7%,相对标准偏差(RSD)≤6.1%(n=6)。基于上述方法,对辽宁省某地区水库水、水库附近土壤、居民自来水中的目标物进行检测,结果表明:水库水目标物质量浓度范围为3.0~3.6 ng/L,水库附近土壤中提取的2-MIB为8.1 ng/L、提取的GSM为17.8 ng/L,居民自来水中的目标物未检出。该方法操作简便、准确可靠,灵敏度高,无需有机溶剂,适合于饮用水中2-MIB和GSM的分析检测。     

高效液相色谱-电感耦合等离子体质谱法测定土壤中不同形态的无机碘

建立了一种有效分离检测土壤中不同形态无机碘(碘离子和碘酸根离子)的高效液相色谱-电感耦合等离子体质谱法(HPLC-ICP-MS)。采用4 mmol/L四丁基氢氧化铵(TBAH)溶液为提取剂进行超声提取,经离心分层,过Na柱和0.22μm滤膜后进行分析,以50 mmol/L碳酸铵溶液(pH 9.8,以25%氨水调节)为流动相,采用AS16阴离子分析柱进行HPLC-ICP-MS测定。结果表明,在优化实验条件下,两种无机碘形态(I~-和IO~-_3)在10～500μg/L范围内线性关系良好,相关系数(r~2)均大于0.999,检出限分别为0.05、0.1μg/L,定量下限分别为2、5μg/L。该方法用于土壤环境中无机碘的测定,其加标回收率为83.8%～108%,相对标准偏差(RSD)为0.5%～3.0%,优于振荡提取法。该方法快速、高效、重现性好、灵敏度高,适用于土壤环境中不同形态无机碘的测定。     

Assessment of iodine content in Brazilian duplicate portion diets and in table salt

Excess dietary intake may increase the risk for the hyperthyroidism in the elderly. This study investigated iodine dietary intake by epithermal neutron activation analysis (ENAA) analyzing duplicate portion diet and fortified table salt samples. Duplicate diet samples were obtained from a group of twenty-five steel mill workers from the city of São Paulo, over a 3-day period. The samples were freeze dried, mixed and homogenized. Fortified table salt brands were collected from the market and were analyzed with no pre-treatment. Assays for the iodine concentration in the table salt samples revealed values between 24 to 65 mg/kg. The average iodine daily intake for the worker’s diets was 813 μg/day, ranging from 402 to 1363 μg/day. In some cases daily intakes were around 10 times higher than the recommended dietary allowance (RDA) value (150 μg/day).     

Determination of organophosphorus pesticides in soil by dispersive liquid-liquid microextraction and gas chromatography

In this article, a rapid and sensitive sample pretreatment technique for the determination of organophosphorus pesticides (OPPs) in soil samples is developed by using dispersive liquid-liquid microextraction (DLLME) combined with gas chromatography-flame photometric detection. Experimental conditions, including the kind of extraction and disperser solvent and their volumes, the extraction time, and the salt addition, are investigated, and the following experiment factors are used: 20 μL chlorobenzene as the extraction solvent; 1.0 mL acetonitrile as the disperser solvent; no addition of salt; and an extraction time of 1 min. Under the optimum conditions, the linearities for the three target OPPs (ethoprophos, chlorpyriphos, and profenofos) are obtained by five points in the concentration range of 2.5-1500 μg/kg, and three replicates are used for each point. Correlation coefficients vary from 0.9987 to 0.9997. The repeatability is tested by spiking soil samples at a concentration level of 5.0 μg/kg. The relative standard deviation (n = 3) varied between 2.0% and 6.6%. The limits of detection, based on a signal-to-noise ratio (S/N) of 3, range from 200 to 500 pg/g. This method is applied to the analysis of the spiked samples S1, S2, and S3, which are collected from the China Agriculture University's orchard, lawn, and garden, respectively. The recoveries for each target analyte are in the range between 87.9% and 108.0%, 87.4% and 108.0%, and 86.7% and 107.2%, respectively.     

Determination of di‐(2‐ethylhexyl)phthalate in environmental samples by liquid chromatography coupled with mass spectrometry

Di‐(2‐ethylhexyl)phthalate (DEHP) was determined in environmental samples such as water and soil. DEHP was extracted from water samples using SPE, whereas for soils pressurized liquid extraction was applied as extraction method, using hexane/acetone (1:1, v/v) as extractant solvent. The use of HPLC coupled to MS provides the basis of the selective determination of DEHP in the analyzed samples. The extraction procedures were validated and good results were found. Recoveries were ranged from 86.0 to 99.8% with RSD lower than 18% and LODs were 0.02 mg/kg and 0.03 μg/L for soils and water, respectively. Finally, the optimized methods were applied to the analysis of real samples and DEHP was not found above the LOQ (0.05 mg/kg) in soil samples whereas it was detected in water samples at concentrations ranging between 0.19 to 0.88 μg/L.     

Multi-residue determination of organophosphorus and organochlorine pesticides in environmental samples using solid-phase extraction with cigarette filter followed by gas chromatography-mass spectrometry

A solid‐phase extraction (SPE) method was developed to extract 14 pesticides simultaneously from environment samples using cigarette filter as the sorbent before gas chromatography‐mass spectrometry (GC‐MS) analysis. Parameters influencing the extraction efficiency, such as the sample loading flow rate, eluent and elution volume, were optimized. The optimum sample loading rate was 3 mL/min, and the retained compounds were eluted with 6 mL of eluent at 1 mL/min under vacuum. Good linearity was obtained for all the 14 pesticides (r²>0.99) from 0.1 to 20 μg/L for water and from 2 to 400 μg/kg for soil samples. The detection limits (signal‐to‐noise=3) of the proposed method ranged from 0.01 to 0.20 μg/L for water samples and from 0.42 to 6.95 μg/kg for soil samples. The developed method was successfully applied for determination of the analytes in real environmental samples, and the mean recoveries ranged from 76.4 to 103.7% for water samples and from 79.9 to 105.3% for soil samples with the precisions (relative standard deviation) between 2.0 and 13.6%.     

A novel method for the determination of a PCB sum value by enzyme immunoassay to overcome the cross-reactivity problem

Many attempts have been made to detect polychlorinated biphenyls (PCBs) by enzyme immunoassay (ELISA). All known ELISAs to PCBs show characteristic cross-reactivity problems. Without any prior information about the composition of the sample, no quantification of the total PCB content is possible. A chemical approach is shown to solve the cross-reactivity problem by the quantitative dechlorination of all PCB congeners to the single compound biphenyl. For the reductive dechlorination palladium on barium sulfate and ammonium formate were used. The dechlorination procedure was optimized to be performed at room temperature in methanol without the exclusion of oxygen or water. For the development of polyclonal biphenyl-antibodies the synthesis of the hapten biphenylhexanoic acid via Grignard cross-coupling is described and an immunization protocol is given. The purity of the used immunological reagents proved to be very crucial. The whole procedure was tested with spiked soil samples. The detection limit for PCBs (Clophen A50) in soil was 1 mg/kg (3.1 μmol/kg). This corresponds to a biphenyl concentration in methanol of 0.1 mg/L (0.6 μmol/L).     

电热板蒸发–重量法测定水中全盐量

建立了电热板蒸发–重量法测定水中全盐量的方法。采用电热板对过滤后的水样进行蒸发预处理,然后以重量法测定样品中的全盐量。取样体积为100 m L,以陶瓷蒸发皿为容器,恒重指标为质量偏差±0.5 mg,设置电热板蒸发温度为350℃,以差减重量法测定水中全盐量,方法线性范围为40~2 000 mg/L,检出限为10 mg/L,3种质量浓度水平实际样品的加标回收率在90.2%~110%之间,样品测定结果的相对标准偏差为2.8%~5.2%(n=6),有证标准物质测定结果与标准值相对误差为–1.9%~2.1%。该方法准确度高、稳定性好,适用于水中全盐量的测定。     

Simultaneous enantioselective determination of fenbuconazole and its main metabolites in soil and water by chiral liquid chromatography/tandem mass spectrometry

A novel and sensitive method was developed for the simultaneous determination of fenbuconazole and its main metabolites enantioselectively using chiral liquid chromatography coupled with tandem mass spectrometry. The separation and determination were performed using reversed-phase chromatography on a cellulose chiral stationary phase, a Chiralcel OD-RH (150 mm×4.6 mm) column, under isocratic conditions at 0.5 mL/min flow rate. The effects of three cellulose-based columns and three amylose-based columns on the separation were also investigated. The elution orders of the eluting enantiomers were identified by an optical rotation detector. The QuEChERS (acronym for Quick, Easy, Cheap, Effective, Rugged and Safe) method and solid-phase extraction (SPE) were used for the extraction and clean-up of the soil and water samples, respectively. Parameters including the matrix effect, linearity, precision, accuracy and stability were evaluated. Under optimal conditions, the mean recoveries for all enantiomers from the soil samples were 82.5-104.1% with 2.7-9.5% intra-day relative standard deviations (RSD) and 5.7-11.2% inter-day RSD at 5, 25 and 50 μg/kg levels; the mean enantiomer recoveries from the water samples were 81.8-104.6% with 2.6-11.4% intra-day RSD and 5.3-10.4% inter-day RSD at 0.25, 0.5 and 2.5 μg/L levels. Coefficients of determination R2≥0.9991 were achieved for each enantiomer in the soil and water matrix calibration curves within the range of 1.0-125 μg/L. The limits of detection (LOD) for all enantiomers in the soil and water were less than 0.8 μg/kg, whereas the limit of quantification (LOQ) did not exceed 2.5 μg/kg. The results of the method validation confirm that this proposed method is convenient and reliable for the enantioselective determination of the enantiomers of fenbuconazole and its main metabolites in soil and water.     

双通道原子荧光光谱法同时测定土壤中的砷和汞

对现有国标检测方法(GB/T 22105.1-2008和GB/T 22105.2-2008)进行改进,采用王水水浴浸提-双通道原子荧光光谱法同时测定土壤样品中砷、汞的含量。采用土壤国家一级标准物质GSS-3,GSS-8,GSS-9与山西农田土壤样品为试验对象,筛选得到检测砷、汞元素含量最佳实验条件及仪器工作条件。砷、汞的质量浓度分别在0~150μg/L,0~2μg/L范围内与荧光强度成良好的线性关系,线性相关系数均大于0.999,砷、汞的检出限分别为0.021,0.0015 mg/kg。测定结果的相对标准偏差为1.81%~4.64%(n=8),砷、汞的样品加标回收率分别为92.7%~103.0%,82.0%~95.5%。经国家一级标准物质验证,该法检出限、准确度和精密度均满足检测要求。改良后的方法可以同时准确、快速地测定土壤中砷、汞,极大地提高了工作效率,可以更好地适应当前大量的土壤分析工作。     

Determination of fluoride in drinking water and in urine of adolescents living in three counties in Northern Chihuahua Mexico using a fluoride ion selective electrode

This study was carried out to determine fluoride in drinking water and in urine of adolescents, ages 15-20 years, living in Northern Chihuahua Mexico. Participants are from a cross-sectional study on health effects of chronic fluoride exposure from drinking water. A total of 201 participants (106 female and 95 male) in the study were recruited from three counties. Samples of drinking water of each county were collected and analyzed using the U.S. EPA Fluoride Ion-Selective Method. Statistically significant difference of fluoride content in water was found among the three counties of recruitment (Cd. Juarez; 0.3 mg/L, Samalayuca, 1.0 mg/L, and Villa Ahumada, 5.3 mg/L). Fluoride content in wells and tap water samples of Villa Ahumada ranged from 5.0 to 5.7 mg/L. Fluoride content of these samples was above the level permitted by Mexican regulations. The fluoride content in bottled water obtained from local stores in Villa Ahumada ranged from 0.3 to 3.7 mg/l.Fluoride in urine samples of each participant was also analyzed using the U.S. EPA Ion-Selective Method. The mean fluoride urine concentration (reported in mg/g creatinine) in adolescents living in these counties was 0.792±0.39, 1.33±0.67 and 2.22±1.16 (Cd. Juarez, Samalayuca and Villa Ahumada), respectively. The high fluoride urinary levels found in participants from Villa Ahumada may be associated to the high fluoride level (5.3 mg/L) in dinking water.The accuracy of measurements was assessed with reference materials in water and in urine. Mean fluoride recovery was 99.0% and 99.6% in water and in urine, respectively. The levels obtained were within the assayed 5% confidence levels.     

微波消解氢化物发生-原子荧光光谱法测定食品接触材料高密度聚乙烯中痕量锑

应用微波消解氢化物发生-原子荧光光谱(HG-AFS)法测定了食品接触材料高密度聚乙烯中痕量锑,采用盐酸作为反应介质,并对最佳分析条件进行了探讨。结果表明,该方法的检出限为0.3μg/L,线性范围为1.0～10.0μg/L,添加水平为0.25、1.0和2.0mg/kg时,加标回收率为80.4%～106.5%,相对标准偏差小于6.9%。该方法操作简便,精密度和准确度好,检出限低,具有实际应用价值。