二氯异氰尿酸钠用于饮水消毒的实验观察

二氯异氰尿酸钠是一种稳定的高效低毒氯消毒剂,有效氯含量可达60～64％。为了解二氯异氰尿酸钠消毒饮用水的安全性,我们比较观察了含等量有效氯漂白粉精片和二氯异氰尿酸钠消毒饮水后卤代烷烃的含量。氯仿和四氯化碳的检测按国家标准GB5750-85进行。     

四种含氯消毒剂使用液的稳定度及实用性探讨

为正确选择和使用含氯消毒剂 ,对 36 5消毒液、氯王(84)消毒液、健之素消毒剂、漂白粉精片 4种含氯消毒剂使用液的稳定度进行了实验 ,并对 4种含氯消毒剂的杀菌力 ,实用性等作了探讨 ,报告如下。1　材料与方法1.1　材料1.1.1　 36 5消毒液　宜昌市卫生防疫科技公司卫生用品厂生产。 5 0 0 m l塑料瓶装。有效氯含量≥ 3%。生产日期 :990 918。1.1.2　氯王 (84)消毒液　长沙雨花消毒剂厂生产。 5 0 0 m l塑料瓶装。未标明有效氯含量。生产日期 :990 80 2。1.1.3　健之素消毒剂　北京长江脉医药科技有限公司生产。 10 0片塑料瓶装 ,有效氯含量 …     

新型自动比色法测定饮用水中的铝

目的建立一种新型快速测定饮用水中铝的自动比色法,并评价其效果。方法在国家标准方法基础上,优化试剂剂型,简化操作步骤,对方法测量范围、精密度、准确度以及实际样品测定进行实验研究。结果方法线性范围为0.008~0.20 mg/L,相关系数(r)为0.9995,检出限为0.006 mg/L,RSD为0.42%~2.60%,自来水加标回收率为87.5%~102%,对铝质控样品的测定结果均在标准定值范围内,相对误差为0.46%~4.15%。采用本法测定饮用水中铝结果与国家标准方法结果基本一致。结论新型自动比色法测定饮用水中铝,快速、准确、精密度高,操作人员无需自行配制试剂,测试所需试剂和样品用量少,节约环保,适合在村镇集中式供水单位普及应用。     

毛细管气相色谱法测定生活饮用水中三氯甲烷和四氯化碳的方法确认

目的:确认调整后的测定生活饮用水中三氯甲烷和四氯化碳的方法能否符合国标检测要求。方法:采用顶空-毛细管气相色谱法测定,以方法的线性范围、线性关系、最低检出限、精密度等各方面的因素进行考察评定。结果:三氯甲烷和四氯化碳分别在0~200 mg/L和0~20.0 mg/L内线性关系良好,最低检出限分别为0.16 mg/L和0.0095 mg/L,RSD分别为4.1%和4.0%,回收率分别为100.3%~109.0%和89.8%~95.4%。结论:本方法的精密度和回收率与国标方法相当,线性范围优于国标法,满足实际检测需要。     

漂白粉中有效氯的简易测定

漂白粉是常用消毒剂,其消毒效果主要取决于有效氯含量。目前常用碘量法测定有效氯含量,因其操作过程麻烦、费时,有时基层部队不易做到,故研究出简易测定法。 (一) 原理 漂白粉在酸性溶液中与碘化钾作用,释放出与氯等当量的碘,再用硫代硫酸钠和游离出来的碘作用,直至黄色再与标准比色板比色。     

氢化物发生-原子荧光光谱法测定大米中镉方法探讨

目的建立实用、简便的测定大米中镉的方法。方法将国标法GB/T5009.15—2003(原子荧光光谱法)的Cd-C13H12N4S-CCl4-H2SO4反应体系改为Cd-K3Fe(CN)6-HCl反应体系,优化实验条件,观察了酸度介质浓度、还原剂浓度、增敏剂浓度等对测定镉信号强度的影响,确定测定镉的最佳条件,并与国标法比较。结果本法线性范围为0.020~5.00μg/L,检出限为0.006 6μg/L,定量限为0.022μg/L,RSD为2.8%~5.7%,加标回收率为91%~106%,配对t检验与国标法比较差异无统计学意义(t=0.274,P0.05)。结论本法操作较简便、灵敏度高、准确性好,适用于大米中镉的批量测定。与国标法比较差异无统计学意义     

石墨炉原子吸收法测定尿液中砷的方法研究

目的建立石墨炉原子吸收法测定液尿中砷的方法。方法应用硝酸和Triton X-100处理尿液,硝酸镍为基体改进剂,测定尿液中砷。结果测定尿砷的线性范围10~50μg/L,r=0.9998,方法检出限为4μg/L;回收率在95.5%~104.0%,RSD为4.4%~5.0%。结论本法简便、快速、准确,精密度高,适应尿液中砷的测定。     

微波消解-乙酰丙酮甲醛分光光度法测定食品中蛋白质

目的:建立简便、准确、绿色的食品中蛋白质的批量测定方法。方法:利用微波溶样技术处理样品,并与乙酰丙酮和甲醛显色定量。结果:微波消解-乙酰丙酮甲醛分光光度法与国标凯氏定氮法相比测定结果差异无显著性,该方法线性范围在5~100μg/10 m l,相关系数r=0.9997,检出限为0.546μg/10 m l,相对标准偏差(RSD)为1.29%~2.21%,加标回收率93.3%~103%。结论:微波消解-乙酰丙酮甲醛分光光度法测定食品中蛋白质方法简便、试剂用量少且环保,方法具有较好的准确度和精密度,适合于批量蛋白质样品的测定。     

蔬菜中有机磷农药多残留的测定

目的:应用气相色谱程序升温和不分流进样方式,测定蔬菜中多组分有机磷类农药残留量。方法:样品经液液萃取,硅胶柱净化,浓缩后由气相色谱法测定,进行准确度,精密度及线性试验。结果:5种有机磷类农药测定的精密度相对标准偏差RSD(%n=6)为078~8.6;检测限为2~4μg/kg;回收率74%~88%。结论:方法快速简便,回收率、精密度较好,符合检测要求,适合蔬菜类食品中多种有机磷农药测定。     

生活饮用水中氰化物含量测定方法的改进

[目的]探讨生活饮用水中氰化物含量测定方法的改进。[方法]通过用消毒液(主要成份为次氯酸钠)代替氯胺T将氰化物转变为氯化氰的方法,对国标方法进行改良。[结果]准确度与精密度试验:低、中和高浓度的平均回收率为95.00%~98.95%,RSD值小于3.96%;与国家标准检测方法比较,差异无统计学意义(P>0.05)。[结论]试剂简单易得,操作容易,用于生活饮用水的测定,结果满意。     

碘量法快速测定乳和乳制品中的β-内酰胺酶

目的:建立了快速筛查乳与乳制品中的β-内酰胺酶的碘量法。方法:检测β-内酰胺酶分解β-内酰胺类抗生素所生成的青霉噻唑酸,间接判断牛奶中是否有β-内酰胺酶。结果:采用碘量法对牛奶中的β-内酰胺酶定性、半定量分析,结果表明,当酶浓度大于20 U/ml时,可以用直接碘量法对其进行定性分析。结论:本方法操作简单、分析时间短、重现性好,适用于乳与乳制品中β-内酰胺酶的间接快速检测。     

食品中二氧化硫残留快速检测方法的研究

[目的]研究和验证改良碘量法快速检测食品中二氧化硫残留的效果。[方法]随机采取水溶性食品94件和水不溶性食品99件,分别用改良碘量法和国标法进行检测,比较两种方法检测食品中二氧化硫的符合性。[结果]两种检测方法对水溶性食品和水不溶性食品中二氧化硫检测结果的符合率为91.0%和83.4%,与国标方法相比,差异均无显著性。[结论]改良碘量法可以作为食品中二氧化硫残留的快速筛检方法。     

A rapid air titration method for determining SO2 concentration in inhalation chambers

A rapid air titration method for determining SO2 concentration in inhalation chambers has been validated using the pararosaniline-formaldehyde (PRA) method of West and Gaeke. This air-titration (iodate) method is an adaptation of iodometric methods using a starch indicator. Potassium iodate and an excess of potassium iodide are used in the reaction. Sampling is completed in ten minutes or less and concentration is calculated by use of a simple formula. Linear equations were derived over the range of concentrations from 0.5 to 100 ppm SO2 for uncorrected iodate bubbler results, data corrected for tandem bubbler concentrations and data corrected for mean iodate bubbler efficiency. Linear correlation with the PRA method over this range was 0.999 for all three sets of data.     

分光光度法测定食品油脂中过氧化值的研究

[目的]探讨食品油脂中过氧化值的分光光度测定法．[方法]参考中华人民共和国国家标准食品卫生检验方法理化部分GB／T5009．37-2003第二法比色法,并采用二氯化铁-硫氰酸钾分光光度法和国标碘量法相比较。[结果]本方法RSD为1．9．9％～4．19％;经配对t检验,表明两种方法的测定结果之间差异无统计学意义（P〉0．05）。能够满足卫生检验要求。该方法检出限为0．1mmoL／kg。[结论]本方法与国标碘量法相比,具有快速、简便、灵敏度高、样品用量少的优点,有较强实用性。     

Antioxidant activities of various fruits and vegetables produced in Taiwan

Fruits and vegetables have been known to contain a variety of antioxidant components. It has been suggested that antioxidants may protect biomolecules from oxidative damage and therefore be associated with reduced risks of cardiovascular disease and certain cancer. The antioxidant abilities of various parts of eight common fruits and vegetables produced in Taiwan were investigated, including tomato, guava, squash, tangerine, wax gourd, pineapple, chayote, and eggplant. Squash, wax gourd, tomato, and guava seeds showed the highest antioxidant activities in thiobarbituric acid assay. Wax guard and squash seeds showed the highest antioxidant activities in iodometric assay. At the level of 1 g fresh sample, low-density lipoprotein peroxidation was inhibited by at least 90% by tomato meat, guava meat, squash seed, wax gourd meat, core, and seed, and eggplant skin. The total phenolic content was significantly correlated with antioxidant activities measured by thiobarbituric acid (r=0.715, P<0.01) and iodometric (r=0.749, P<0.01) assays. The results of this study could be used for development of merchandise with potential health benefits from agricultural products.     

Antioxidant activities of various fruits and vegetables produced in Taiwan

Fruits and vegetables have been known to contain a variety of antioxidant components. It has been suggested that antioxidants may protect biomolecules from oxidative damage and therefore be associated with reduced risks of cardiovascular disease and certain cancer. The antioxidant abilities of various parts of eight common fruits and vegetables produced in Taiwan were investigated, including tomato, guava, squash, tangerine, wax gourd, pineapple, chayote, and eggplant. Squash, wax gourd, tomato, and guava seeds showed the highest antioxidant activities in thiobarbituric acid assay. Wax guard and squash seeds showed the highest antioxidant activities in iodometric assay. At the level of 1 g fresh sample, low-density lipoprotein peroxidation was inhibited by at least 90% by tomato meat, guava meat, squash seed, wax gourd meat, core, and seed, and eggplant skin. The total phenolic content was significantly correlated with antioxidant activities measured by thiobarbituric acid (r=0.715, P<0.01) and iodometric (r=0.749, P<0.01) assays. The results of this study could be used for development of merchandise with potential health benefits from agricultural products.     

2007年新疆奎屯垦区居民食用碘盐现状调查

[目的]了解奎屯垦区合格碘盐的食用情况。[方法]每个团场随机抽取32份居民食用盐,碘盐检测采用GB/T13025.7-1999直接滴定法。合格碘盐的判定标准为20~50 mg/kg,非碘盐的判定标准为<5 mg/kg。[结果]共抽取居民户碘盐288份。其中,272份属合格碘盐,10份不合格碘盐(包括2份>50 mg/kg的碘盐),6份非碘盐,合格率为94.44%。[结论]奎屯垦区居民食用碘盐情况良好,但个别团场食用碘盐合格率低于90%。应加强市场监督,加大抽检频次,打击非碘盐的冲销。     

济南市区医院废水余氯含量

目的了解济南市医院排放废水中的余氯含量。方法2003年6-9月采集济南市区12家医院排放的废水,采用碘量滴定法测定医院排放废水中余氯的含量,并测定了废水中的粪大肠菌群。结果济南市区12家医院排放废水中余氯含量为3.7～128mg/L,平均为27.6mg/L。废水中的粪大肠菌群均<90个/L,符合国家标准。结论济南市区医院排放废水中余氯含量过高,对水环境会造成二次污染。     

Gonorrhoea caused by a mixture of penicillinase-positive and -negative gonococci: a case report

A 23-year-old unmarried man was infected with gonorrhoea from a prostitute in Fukuoka City and was treated with ampicillin which resulted in failure. By a rapid iodometric test it was found that the isolates before the treatment were penicillinase-negative. After the ampicillin treatment, however, the isolates turned to penicillinase-positive but were, in fact, a mixture of penicillinase-positive and penicillinase-negative gonococcal strains. Treatment by spectinomycin and doxycycline resulted in failure but the gonorrhoea was cured by ribostamycin.     

Iodine deficiency status and iodised salt consumption in Malaysia: findings from a national iodine deficiency disorders survey

A nationwide cross-sectional school-based survey was undertaken among children aged 8-10 years old to determine the current iodine deficiency status in the country. Determination of urinary iodine (UI) and palpation of the thyroid gland were carried out among 18,012 and 18,078 children respectively while iodine test of the salt samples was done using Rapid Test Kits and the iodometric method. The results showed that based on WHO/ ICCIDD/UNICEF criteria, the national median UI was 109 μg/L [25th, 75th percentile (67, 166)] showing borderline adequacy. The overall national prevalence of iodine deficiency disorders (IDD) with UI<100 μg/L was 48.2% (95% CI: 46.0, 50.4), higher among children residing in rural areas than in urban areas. The highest prevalence of UI<100 μg/L was noted among the aborigines [(81.4% (95% CI: 75.1, 86.4)]. The national total goitre rate (grade 1 and grade 2 goitre) was 2.1%. Of 17,888 salt samples brought by the school children, 28.2% (95% CI: 26.4, 30.2) were found to have iodine content. However, the overall proportion of the households in Malaysia using adequately iodised salt as recommended by Malaysian Food Act 1983 of 20-30 ppm was only 6.8% (95% CI: 5.1, 9.0). In conclusion, although a goitre endemic was not present in Malaysia, almost half of the states in Peninsular Malaysia still have large proportion of UI level <100 μg/L and warrant immediate action. The findings of this survey suggest that there is a need for review on the current approach of the national IDD prevention and control programme.