干旱因素对尿、血清和唾液含氟量的影响

我们曾就干旱因素影响两个地方性氟中毒(地氟病)病区人群的某些指标作过报道。本文重点讨论其影响同一人群尿、血清和唾液含氟量情况,旨在为地氟病防治研究提供参考。     

塞曼效应石墨管原子吸收法测定人尿痕量镉

以磷酸二氢铵（ＮＨ４、Ｈ２ＰＯ４）作基体改良剂，用塞曼效应扣除背景直接进行石墨管原子吸收法测定尿中痕量镉，该法最低检出限为０．０２４μｇ／Ｌ，相对标准在４．５％，回收率达９５－１１２％。．     

Matrix effects in analysis of dialkyl phosphate metabolites of organophosphate pesticides in urine by gas chromatography/tandem mass spectrometer

Urinary dialkyl phosphate metabolites (DAPs) are used as biomarkers to evaluate human exposure to organophosphate pesticides. The objective was to evaluate potential artifacts in urinary DAPs analysis during sample preparation and method calibration. Diluted urine pools were commonly used to prepare calibration standards to minimize the effects due to the complexity of urine matrix. Matrix effects on measurements of DAPs were evaluated by spiking known amount of standards into distilled water, synthetic urine and diluted urine pool. Different matrices resulted in similar concentrations detected for all target compounds, except dimethylphosphate (DMP) with the deviation of measurement as large as eight times the spiked amount. In this study, we also found that urinary particles, which usually appeared after thawing frozen human urine samples, could affect the measurements of DAPs, especially DMP and diethylthiophosphate (DETP). Results of DAPs measurements in three types of sample matrices, i.e. urine without particles, urine with particles and particles only were compared. DETP could be subject to large error during this preparation step. The use of deuterated and ¹³C₁₂-labeled DAPs as internal standards is also evaluated. Overall, these issues can cause misidentification and inaccuracies, which may significantly affect the data quality.     

粪尿分集全方位负压排臭生态卫生旱厕应用实例

介绍了粪尿分集生态卫生旱厕的特点及应用效果，该厕能节约和保护水资源，排泄物可再次利用，能形成可持续的完整的生态系统。具有较好的发展前景。     

Validation of reliable and selective methods for direct determination of glyphosate and aminomethylphosphonic acid in milk and urine using LC-MS/MS

Simple high-throughput procedures were developed for the direct analysis of glyphosate [N-(phosphonomethyl)glycine] and aminomethylphosphonic acid (AMPA) in human and bovine milk and human urine matrices. Samples were extracted with an acidified aqueous solution on a high-speed shaker. Stable isotope labeled internal standards were added with the extraction solvent to ensure accurate tracking and quantitation. An additional cleanup procedure using partitioning with methylene chloride was required for milk matrices to minimize the presence of matrix components that can impact the longevity of the analytical column. Both analytes were analyzed directly, without derivatization, by liquid chromatography tandem mass spectrometry using two separate precursor-to-product transitions that ensure and confirm the accuracy of the measured results. Method performance was evaluated during validation through a series of assessments that included linearity, accuracy, precision, selectivity, ionization effects and carryover. Limits of quantitation (LOQ) were determined to be 0.1 and 10 µg/L (ppb) for urine and milk, respectively, for both glyphosate and AMPA. Mean recoveries for all matrices were within 89–107% at three separate fortification levels including the LOQ. Precision for replicates was ≤7.4% relative standard deviation (RSD) for milk and ≤11.4% RSD for urine across all fortification levels. All human and bovine milk samples used for selectivity and ionization effects assessments were free of any detectable levels of glyphosate and AMPA. Some of the human urine samples contained trace levels of glyphosate and AMPA, which were background subtracted for accuracy assessments. Ionization effects testing showed no significant biases from the matrix. A successful independent external validation was conducted using the more complicated milk matrices to demonstrate method transferability.     

广州市幼儿园儿童对羟基苯甲酸酯内暴露水平及分布特征

对羟基苯甲酸酯是一种防腐剂和抑菌剂,广泛应用于食品、药品和化妆品等行业。研究已证实对羟基苯甲酸酯具有一定的生殖毒性、发育毒性以及雌激素活性。通过测定尿液中对羟基苯甲酸酯的含量,可综合地反映出人体对羟基苯甲酸酯的暴露情况。本研究采集66例广州市某幼儿园儿童尿样,采用高效液相色谱-串联质谱检测了其中对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯和对羟基苯甲酸苄酯等5种对羟基苯甲酸酯浓度水平。对羟基苯甲酸甲酯、对羟基苯甲酸乙酯和对羟基苯甲酸丙酯的中值浓度分别为4.42、1.39和1.74μg·L~(-1)。对羟基苯甲酸丁酯和对羟基苯甲酸苄酯检出率较低。本研究中广州市幼儿园儿童对羟基苯甲酸酯含量水平远低于欧美国家同龄儿童,而与印度同龄儿童水平相当。相关性分析显示,对羟基苯甲酸甲酯与对羟基苯甲酸丙酯呈一定程度的相关性,暗示二者可能有相同的来源。     

Determination of pentachlorophenol in human urine using solid phase extraction and GC‐MS analysis with stable isotope dilution

A method for the determination of pentachlorophenol (PCP) in human urine was developed. Urine samples were fortified with ¹³C₆‐IabeIed PCP and hydrolyzed with sulfuric acid prior to extraction. The urine samples were then passed through preconditioned solid phase extraction cartridges containing octadecylsilane adsorbent. The PCP was subsequently eluted from the cartridge with ethyl acetate and converted to pentachloroanisole prior to GC‐MS analysis. GC‐MS quantitation was performed using the technique of stable isotope dilution. Percent recoveries averaging 100, 97, and 111% were obtained for replicate urine samples fortified with approximately 2, 20, and 200 ng/mL of PCP, respectively. The method detection limit was estimated to be 0.2 ng/mL.     

Clinical and analytical follow‐up of 25 persons exposed accidentally to beryllium†

An accidental exposition of 25 persons to beryllium dust was used to follow up trace analytical and clinical parameters over a period of 10 months. Although no exposed person shows any symptoms of an acute beryllium intoxication, up to 5‐fold increased beryllium concentrations could be analysed in serum samples about 10 hours after exposition. The beryllium clearance shows a biological half time in the range of 2 to 8 weeks. The beryllium determination in the nanogram range was carried out using a combined method by flameless a.a.s. with a detection limit of 0.6 ppb Be and a relative standard deviation from 20 to 4% in relation to the concentration range of beryllium measurement.

Beryllium analyses are completed by thorax X‐ray, spirometry, y‐globulins and liver enzymes (SGOT, SGPT), which have shown no pathological values. Because it is known for beryllium to sensitize the cellular immune response, neopterin measurement was used to determine the activity of the immune system. Neopterin, a pteridine synthesized by activated macrophages after stimulation by gamma‐interferon derived from sensitized T‐lymphocytes, was determined in urine samples by HPLC combined with an fluorescence detector. Only in two cases a slight increase of neopterin has been found. As a result of this study it can be summarized, that a short‐time exposure to beryllium (10–20 h), which results in a increase of beryllium in serum to the fivefold normal beryllium level, does not initiate any symptoms of an acute beryllium intoxication. The exposed persons are controlled in future to evaluate the further course.     

Concentrations of selected metals in blood,serum, and urine among US adult exclusive users of cigarettes,cigars, and electronic cigarettes

Data from National Health and Nutrition Examination Survey for 2013–2014 were used to compare observed levels of selected metals in blood, serum, and urine among US adults aged ≥20 years for exclusive cigar, cigarettes, and e-cigarette users. Adjusted geometric means for e-cigarette users were found to be higher than for cigar users for blood manganese (10.3 vs. 7.9 µg/L, p = 0.02). Cigar users were found to have lower adjusted geometric means than cigarette users for urine cobalt (0.22 vs. 0.4 µg/L, p = 0.04) and urine antimony (0.03 vs. 0.06 µg/L, p = 0.03). Adjusted levels of blood selenium, serum copper, selenium, and zinc, and urine arsenic, barium, molybdenum, tin, strontium, thallium, tungsten, and uranium were found to be comparable among cigarettes only, cigar only, and electronic cigarettes only users. However, irrespective of the comparative levels of these metals among cigar, cigarette, and e-cigarette users, focus must be to assess the short- and long-term health effects of the exposure to these metals particularly nanoparticles via inhalation from e-cigarette aerosols.