Determination of N-nitrosodiethanolamine in urine by gas chromatography thermal energy analysis: application in workers exposed to aqueous metalworking fluids

 Objective: The aim of this study was to describe a detailed and validated methodology designed for the analysis of carcinogenic N-nitrosodiethanolamine (NDELA) down to sub-μg/l levels in urine and its application to a number of workers exposed to NDELA-contaminated aqueous metalworking fluids (MWF). Methods: Following a work-up procedure based on solid-phase extraction of NDELA, the urinary extracts were analysed without derivatization by gas chromatography on a polar wide-bore column with chemiluminescent detection using a thermal energy analyser (TEA). N-Nitroso-(2-hydroxypropyl)amine was used as an internal standard. The method was applied to 12 workers using “nitrite-free” or “nitrite-formulated” MWF and to 15 unexposed subjects. The NDELA content of the MWF was also determined using a similar, but simpler method able to easily quantify NDELA down to at least 0.1 mg/l. Results: Contamination by NDELA traces of some chemicals used for the sample preparation, particularly ethyl formate, must be carefully checked since it can give rise to false-positive results of up to 1 or 2 μg/l. The response was linear in the range of 0–500 μg/l. Between 0.5 and 10 μg/l, the recovery rate was close to 95%, while repeatability ranged from 12.5 to 6.4% (n = 5). The detection limit was 0.3 μg/l (Signal/noise = 3). No detectable NDELA could be observed in the control workers. There was no significant increase in NDELA levels at the end of shift spot samples from an exposed worker over 1 week. Higher NDELA concentrations were found in two workers (4.3 and 10.7 μg/l) exposed to “nitrite-formulated” fluids (contaminated with 65 and 18 mg NDELA per l, respectively) than in nine workers (range, 0.4–1.3 μg/l exposed to “nitrite-free” fluids with lower levels of NDELA (range, 0.5–6.6 mg/l). Conclusion: The detailed methodology described in this work and applied to a limited industrial situation was found to be suitable for monitoring NDELA in the urine of workers exposed to aqueous MWF. A much larger screening has been undertaken with the aim of obtaining better information on the real exposure of workers sometimes exposed to “nitrite-formulated” fluids that are still used. Received: 8 December 1998 / Accepted: 3 April 1999     

Detection and typing of human papillomavirus DNA in paired urine and cervical scrapes

The prevalence of human papillomavirus (HPV) in paired cervical scrape and urine specimens from 144 women attending a clinic for genitourinary medicine was determined by polymerase chain reaction (PCR) and nested PCR, using degenerate and general primer pairs localized within the L1 region. HPV typing was by restriction fragment length polymorphism (RFLP), type-specific PCR (HPV 6, 11, 16, 18, 33), and partial DNA sequencing of PCR products. HPV DNA was detected in 114 (84%) women. HPV DNA was detected in the specimens of 58 patients after amplification with MY09/MY11 primers and in a further 54 patients after nested PCR with the GP5 + /GP6 + primers. A total of 106/136 (78%) of women had HPV DNA positive cervical scrapes and 89 (65%) had HPV DNA positive urine specimens. Both the urine and cervical specimens of 81 women were positive. In 25 women HPV DNA was detected in the cervical specimen only, and in 8 women HPV DNA was detected in the urine specimens only. A total of 108 specimens from 75 patients were typed. For 33 patients HPV typing was achieved in both the cervical and the urine specimens and 19 women had identical types in paired specimens. Multiple HPV infections could be detected in 15 (20%) of 75 women where either the cervical and urine specimen or both of the specimens could be typed. More then one HPV type was found in 8 specimens and from multiple sites (cervix and urinary tract) in the same patients on 7 occasions. The results of this study indicate that the detection of HPVs in the urogenital tract can be maximised through the testing of both cervical scrapes and urine specimens in conjunction with the use of a nested PCR to increase the sensitivity of HPV DNA detection. Also, urine cannot be a direct substitute for a cervical scrape as different HPV types are often detected in the urine compared with those detected in the cervix.     

HPLC-ECD测定人血及尿中儿茶酚胺浓度

目的建立简便快速准确测定体内儿茶酚胺的方法,为临床检测和研究提供技术支持。方法血浆和尿样经Al2O3吸附,净化,0．2mol·L－1HCl洗脱,以C8为固定相,磷酸缓冲液（pH2．7）、200mg·L－1SDS、10mg·L－1EDTA、6％乙晴为流动相,分离去甲肾上腺素（NE）肾上腺素（E）、多巴胺（DA）,电化学检测,工作电压＋0．75V,灵敏度4nA,以外标法定量。结果NE,E,DA分离良好,且不受体内其他内源性物质及代谢物干扰。绝对回收率血浆为（71．58±5．57）％,尿样为（75．65±6．22）％。血浆相对回收率为（95．83±4．98）％,尿样为（101．5±7．17）％,血样线性范围0．1～20μg·L-1,尿样0．5～80μg·L-1,最低检测浓度0．05μg·L－1。结论操作、分析简便快速,专一性强,无干扰,重复性较好,适合于儿茶酚胺的临床测定与研究。     

氟致大鼠尿锌水平变化及对血浆SOD影响观察

用含１１０ｍｇ／Ｌ氟化钠的双蒸水饲养Ｗｉｓｔａｒｔ大鼠４周,检测大鼠尿锌、血浆锌和血浆ＳＯＤ水平。结果表明,实验组大鼠尿锌排泄量明显高于对照组（Ｐ＜０．０５）,血浆ＳＯＤ含量明显低于对照且（Ｐ＜０．０５）。     

Isolation and determination of quaternary ammonium compounds by means of amberlite XAD-columns and thin layer chromatography

The potentials of XAD-columns for the isolation of quaternary ammonium compounds from aqueous media have been investigated. When adequate amounts of counter ions (perchlorate, chloride, phosphate, nitrate) were added to the aqueous sample, to the column pretreatment fluid and to the aqueous washing fluid, most quaternary compounds investigated were retained on the column and could be recovered by elution with methanol. This approach proved also suitable for urine. Quantitation of quaternaries isolated in this way from urine samples could be performed on silicagel thin layer plates through visualization with iodine, followed by densitometric evaluation. For decamethonium detection limits were 0.1 g/ml. Recoveries at the 1 g/ml level were between 80–90% with variation coefficients of less than 10%.Presented at the European Meeting of The International Association of Forensic Toxicologists, July 4–7, 1978, Utrecht, The Netherlands     

Measurement of the urinary metabolites of n-hexane,cyclohexane and their isomers by gas chromatography

Summary A gas chromatographic method for analyzing the urinary metabolites of n-hexane (2-hexanol, 2,5-hexanedione, 2,5-dimethylfuran and -valerolactone), of 2-methylpentane (2-methyl-2-pentanol), of 3-methylpentane (3-methyl-2-pentanol), and of cyclohexane (cyclohexanol) was developed. Processing of urine and the gas chromatographic conditions are described. The recovery rate of all hexane metabolites, except 2,5-dimethylfuran, ranged between 92 and 100%. The variation coefficient of metabolites determination was between 1.5 and 5%, apart from 2,5-dimethylfuran determination for which the variation coefficient was 15%. The detection limits ranged between 0.2 and 0.7 mg/1 and between 0.05 and 0.1 mg/1 when a packed or capillary column was used. Results obtained from a packed and capillary column are discussed.     

Urine test strips: reliability of semi-quantitative findings under tropical conditions

Semi-quantitative urinalysis with urine reagent strips (URS) for erythrocyturia (EU), leucocyturia (LU) and proteinuria (PU) was performed in Congolese and Sudanese school children withSchistosoma haematobium and/orS.mansoni infection. Quantitative urinalysis was performed on the same specimen using microscopy and a Neubauer counting chamber for EU and LU and the Coomassie blue dye-binding assay for PU. Microscopically detectable EU of more than 10 cells/l was found in 63% of all samples and LU of more than 20 cells/l was found in 60% of all samples. With the Coomassie blue method, PU of more than 150 mg/l was detected in 51% of all samples. URS gave positive results of grade 1–3 for EU in 69% of all samples, for LU in 63% of all samples and for PU in 66% of all samples. The sensitivity and specificity of URS compared with standard reference methods were as follows: EU 95% and 75%, LU 81% and 81% and PU 90% and 56%. When the results of all three test were combined, URS differentiated abnormal from normal urine specimens with a sensitivity of 94% and a specificity of 70%. Median quantitative results showed a good correlation with semiquantitative URS readings for all parameters, but there was a wide range of URS scores.We concluded that URS sensitively detect urinary abnormalities and thus may be used as a general screening method under field conditions when more specific methods cannot be performed. In the hospital laboratory,urine microscopy with a counting chamber would be preferred to URS as a sole method for EU and LU detection; URS is useful for the detection of PU in the tropical hospital laboratory where an appropriate quantitative method with a better specificity may not be available.     

Prediction of survival and recurrence in bladder carcinoma

Summary We have followed a large population of patients receiving radiation treatment for bladder carcinoma with respect to survival and recurrence-free survival. Bivariate and multivariate life table analyses have been performed using a set of independent variables. The most important were T class, grade (G), urinary carcinoembryonic antigen (U-CEA) taken before treatment and cytological analysis 4 months after treatment. We compared the usual way of classifying a patient (T+G) with the combination of U-CEA and cytology since the latter two variables seemed to have great prognostic importance. The analyses show that T+G gives the best significance for survival (P=0.0003) while U-CEA and cytology is better for recurrence-free survival (=0.0002). 0.0002).     

Occupational chronic exposure to organic solvents

Summary A group of printing workers (n = 34) exposed to toluene was examined according to the concentrations of hippuric acid, phenol, o-cresol, and (m+p)-cresol in urine. The average concentration in the air of the workroom was 23 ppm. It is shown that, besides hippuric acid, small amounts of o-cresol. which is not a normal constituent of urine, were formed from toluene. The occurrence of o-cresol could be proved by mass spectrometry. On account of the small amounts of benzene present in industrially used toluene—in this case 0.025%—the average concentration of phenol in urine of the exposed group was significantly higher statistically than in urine from the controls .     

Action of the competitive angiotensin II antagonist saralasin during the initial phase of glycerol-induced acute renal failure of the rat

Summary The effects of the competitive angiotensin II antagonist saralasin (1-sarcosine-8-alanine-5-isoleucine-angiotensin II) on renal function in healthy rats and in rats with myohemoglobinuric acute renal failure were studied. Acute renal failure was induced by an intramuscular injection of 50% glycerol (10 ml ·kg^–1). Functional impairment of the glycerol treated animals consisted in a decrease of renal blood flow (electromagnetic flowmeter) and GFR and in an increase of urine volume and arterial blood pressure.In healthy rats saralasin (6 g·kg^–1·min^–1 i.v.) had no renal effects by itself but antagonized the angiotensin II (200 ng·kg^–1·min i.v.) induced fall of renal blood flow and GFR and the increase of arterial blood pressure. Given to glycerol treated animals saralasin did not induce any change of arterial blood pressure, renal blood flow, GFR or the urinary excretion of fluid and sodium.Supported by Deutsche Forschungsgemeinschaft