Objective Proficiency testing for nitrogen content in soybean flour and corn flour by digital automatic nitrogen analyzer.Methods Using LabX software to establish a digital operation interface,setting the parameters,and the determination of nitrogen content in soybean flour and corn flour by digital automatic nitrogen analyzer.Results Determination of nitrogen content in soybean flour and corn flour by digital automatic nitrogen analyzer,the average is within the scope of the proficiency testing,the results were satisfactory,the recoveries are between 99.0％ and 100.4％,the relative standard deviation is 0.82％.The quality control samples were measured,the nitrogen content is within the scope of the certificate.Conclusion Digital automatic nitrogen analyzer to determine the nitrogen content of soybean flour and corn flour realized the experimental process fully-automatic operation interface,it has advantages of simply,fastly,accurately and efficiently.

目的 用数字化自动电位滴定仪测定甜面酱中氨基酸态氮方法进行了探讨.方法 用LabX软件建立数字化的操作界面,并设置甜面酱中氨基酸态氮的各项参数进行数字化自动电位仪滴定的测定.结果 数字化自动电位滴定仪甜面酱中氨基酸态氮的测定结果与国标法比较差异无显著性,相对标准偏差是1.74％.结论 数字化自动电位滴定仪测定甜面酱中氨基酸态氮实现了实验过程全自动化的操作界面,具有简便、快速、准确、高效的优点.

由于海产品等在复杂的海洋环境中生长,长期受到工业和生活废水的污染,因此海产品可能含有各种复杂的成分,特别是砷化物(包括无机砷和有机砷).常见的砷化物有三价砷、五价砷等无机砷和一甲基砷酸、二甲基砷酸等有机砷,有机砷毒性小,而无机砷是剧毒物质,海产品中可能含有大量的有机砷.目前按照国家标准GB/T5009.11-2003无机砷测定的前处理方法,样品中的无机砷和有机砷可能分离不完全,有机砷等反应生成的砷氢化合物对无机砷的测定造成干扰,因此用普通型原子荧光仪测定海产品中的无机砷时[1],易造成假阳性的测定结果.本文用原子荧光形态分析仪对海产品中的无机砷测定方法进行分析和探讨.

通过建立数学模型,对电感耦合等离子体质谱法测定小麦粉中的铅的进行不确定度评定.分析并计算了各不确定度分量,计算合成标准不确定度和扩展不确定度.结果表明,方法测量不确定度主要由曲线校正和样品测试重复性引入,而定容体积和称样过程的不确定度可忽略不计.

Objective:To cause poisoning explore together nitrite pol ution water pipe drinking water, wel water, vomit and blood samples were measured, and the impact factor of the detection process (appropriate dilution factor) to explore the nitrite content. Methods:GB/T5750-2006 and GB5009.33-2010 national standard test methods for drinking water and wel water, vomit and blood nitrite content were determined. Results:Application of the impact of factors such as drinking water, wel water, vomit and blood samples and nitrite content and District CDC experimental results after a paired t-test, t10 = 1.77, t (0.05,9) = 2.26, t10 <t(0.05,9)impact factor results show that there was no significant difference (P> 0.05), and high recovery rate, precision.Conclusion:Experimental results show that contaminated drinking water, wel water, vomit and blood nitrite content, the impact factor, the role of nitrite content appropriate impact factor is essential results; affect the application of the factor, with accurate, time-saving, sensitive and easy.

<正>一次性环保餐具在餐饮和很多食品行业中使用,如果使用过程中与食品直接接触的时间较长,有害化学成分可能会迁移到食品中,特别是一次性餐具材料中的有毒物质,一旦遇到高温、高油、醋等可直接转移到食物中,造成食品的化学污染。如果人吃了污染严重的食物,有可能引起肝脏、肾脏的损害,所以对人体健康造成很大的影响;另外我国食品卫生法明确规定,对食品包装材料(包括一次性环保餐具)必须进行卫生检测[1]。

Objective:To study the colloidal gold test strip and use this method to determine the level of nitrofuran in AHD residues.Methods:Colloidal gold test strip was used to determine the level of nitrofuran in AHD residues in milk,and the result was compared with that of ELISA.Results:The determination result was consistent with that of ELISA,the coincidence rate was 100%.With paired t test,there was no significant difference between the results of the two methods(P>0.05).The recoveries were 85%~92%,the RSD was 14.5%.Conclusion:The colloidal gold test strip was rapid,accurate,time-saving,sensitive and handy in determination of nitrofuran residues in milk.

Objective: To develop a method for determination of zinc in extraction liquor from rubber products by inductively coupled plasma mass spectrometry. Methods: The sample was directly determined by inductively cou- pled plasma mass spectrometry and internal standard method was used to correct matrix interference. Results: No significant difference was observed between ICP - MS and of national standard method ( P > 0. 05) ,recoveries were 93. 0% ～ 99. 5% ; relative standaard deviation was 2. 59% . Conclusion: ICP - MS was suitable for determination of zinc in extraction liquor from rubber products with the advantages of accuracy,simpleness and rapidness.

Objective:To analyze the monitoring results of protein and melamine levels in commercial milk powder and dairy products in Guangdong,and provide a basis for food safety supervision.Methods: A total of 118 milk powder and dairy products samples in 3 kinds were randomly selected from 3 prefecture-level cities and analyzed in accordance with GB5009.5-2010 and GB/T22388-2003.Results: In Guangdong,the qualified rates of protein in commercial available milk powder,liquid milk and milk beverage were 76.7%,84.4% and 93.0% respectively,while the detection values of melamine were all lower than the national standard values,whose qualified rates were 100%.Conclusion: The qualified rate of protein in milk powder was low,so surveillance and supervision of protein level in milk powder,especially in infant milk powder,should be strengthened strictly.

Objective:To develop a method for determination of copper,arsenic and cadmium in shrimp powder by inductively coupled plasma mass spectrometry.Methods: After microwave digestion,the samples were determined directly by inductively coupled plasma mass spectrometry,using mixed internal standard to correct matrix interference and signal drifting.Results: The RSDs of the method were less than 3.0%,recoveries were 95.0%(110%,the results of analyzing standard materiel were satisfactory.Conclusion: The method is precise and accurate.

[Objective]To study HIV prevalence among the voluntary blood donors,explore the positive and effective measures to improve voluntary blood donation by ensuring blood safety.[Methods]The data of HIV infection among voluntary blood donors in Fuzhou were analyzed.[Results]There were 370 220 voluntary blood donors during 2006-2010.Among them,31 donors were HIV infected.The infection rate was 0.008 4%.During 2006-2010,HIV positive were detected in 2 cases,5 cases,2 cases,4 cases and 18 cases.29 males and 2 females among them.The age focused on 28 to 35 years old.Terms of occupational distribution,unemployed in 11 cases,cadres and staff in 6 cases,4 cases of migrant workers,students in 3 cases,3 cases of attendants,medical staff 1,unknown 3.Of them 64.52% were temporary population,87.10% were transmitted by sexual behavior.[Conclusion]The epidemic situation of HIV is becoming serious in Fuzhou city with HIV positive cases among students,cadres and blood donors.

镉是一种常见的食品中容易富集或受其污染的有毒元素.人吃了这类食品后,容易在体内积累,最终对人体的健康产生很大的影响.因此对食品中的镉进行检测是必要的~(1,2).电感耦合等离子体质谱(ICP-MS)法作为一种无机元素分析方法,已经被广泛应用到金属元素的分析中~(3,4).本文用微波消解对豆奶粉样品进行预处理,然后用ICP-MS测定消化液中镉的含量.

Objective:To develop a method for determination of 14 rare earth elements in animal food by inductively coupled plasma mass spectrometry.Methods:After microwave digestion,the samples were determined directly by inductively coupled plasma mass spectrometry which used mixed internal standard to correct matrix interference and signal drifting.Results:The range of detection limit of observed 14 elements were all below 10 ng/kg.The RSD was less than 3.6%,and recoveries 97.0%～106%.All the results of analyzing standard materiels were satisfactory.Conclusion:This method is simple,rapid and accurate and can be used to determine 14 rare earth elements in animal food.

Objective To explore the assay method of acidity of fresh royal jelly determined by automatic potentiometric titrimeter.Method The digital operating interface was set up with LabX software,and each parameter of automatic operating interface was set.The acidity of fresh royal jelly was determined by automatic potentiometric titrimeter.Results The recoveries were from 90.0% to 96.3%,and the RSD was 0.24%.Conclusion The results of acidity for fresh royal jelly determined by automatic potentiometric titrimeter were no significant difference with the results obtained by GB/T 9697—2002.The digital operating interface in whole experiment process was fulfilled.The method has the characteristic of simple,fast,accuracy and efficiency.

目的:了解牙膏中含氟情况,为预防龋齿提供依据.方法:牙膏中可溶性氟、游离氟的测定均采用氟离子选择电极测定.结果:可溶性氟含量范围为 3.54～810 mg/kg、游离氟含量范围为 0.54～174 mg/kg.方法的精密度及回收率均符合要求.结论:游离氟含量均达不到GB8372-2001要求,提示生产厂家在选择原料及磨擦剂时要反复研究.

目的了解广州市流动人群A群流行性脑脊髓膜炎(简称流脑)抗体水平及流脑多糖菌苗的接种情况.方法采用横断面研究、整群抽样方法,于2000年10～12月在广州市流动人口聚集地采集流动人群血清样本,应用酶联免疫吸附试验,进行A群流脑抗体检测,并进行问卷调查.结果调查的1026名流动人群中,A群流脑抗体阳性917人,阳性率为89.28%,GMT为1:17.流脑菌苗接种率为17.64%,181人已接种流脑菌苗者抗体阳性率(93.90%)和GMT(1:21.86)明显高于845人未接种者(阳性率和GMT分别为88.40%和1:16.11)(P＜0.05).抗体阳性率和GMT有随年龄增长而下降的趋势,＜20岁组最高(93.6%),40岁以上组最低(71.4%),各年龄组间的差异有显著性(P＜0.05).结论广州市流动人群对A群流脑具有较高的免疫力,但人群流脑菌苗接种率低,且高年龄组人群抗体水平较低.提示今后在流动人群聚集地开展流脑菌苗接种以提高其免疫水平实属必要.

目的通过对健康人群流行性脑脊髓膜炎(流脑)病原菌带菌监测,为流脑防治工作提供科学依据.方法采集广州市1994～2003年健康人群咽拭子,用巧克力琼脂培养分离,疑似菌落作生化反应及血清学鉴定.结果1994～2003年,除1997年及2002年未检出外,其余年份共分离到流脑菌株24株,各年份的总带菌率为0.80%～1.85%.菌株鉴定,主要为B群脑膜炎奈瑟菌(Nm),共15株,占62.5%.结论近年来本市人群的流脑病原菌的隐性感染不高,主要为20岁以上成人,应在成人中加强流脑的防治措施,并警惕B群Nm引起的流脑流行.