Isotope Dilution UPLC-APCI-MS/MS Method for the Quantitative Measurement of Aromatic Diamines in Human Urine: Biomarkers of Diisocyanate Exposure.

Urinary diamines are biomarkers of diisocyanate exposure. Diisocyanates are considered as skin and respiratory sensitizers and are the most frequently reported cause of occupational asthma. Herein we report on the development and validation of an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the measurement of five aromatic diamines, 4,4'-methylenedianiline (MDA), 2,4-toluenediamine (4TDA), 2,6-toluenediamine (6TDA), 1,5-naphthalenediamine (NDA), and p-phenylenediamine (PPDA) in human urine. The method incorporates sample preparation steps, which include a 4 h acid hydrolysis followed by high-throughput solid-phase extraction prior to chromatographic separation. Chromatographic separation was achieved using a C18 reversed phase column with gradient elution of basic mobile phases (pH 9.2). The duty cycle of the method was less than 5 min, including both the column equilibration and autosampler movement. Analytical detection was performed using positive ion atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS/MS) in scheduled multiple reaction monitoring (sMRM) mode. Excellent linearity was observed over standard calibration curve concentration ranges of 3 orders of magnitude with method detection limit ranging from 10 to 100 pg/mL. The interday and intraday reproducibility and accuracy were within ±15%. This method is fast, accurate, and reproducible and is suitable for assessment of exposure to the most common aromatic diisocyanates within targeted groups as well as larger population studies such as the National Health and Nutrition Examination Survey (NHANES).

Exposure of hairdressers to aromatic diamines: an interventional study confirming the protective effect of adequate glove use.

OBJECTIVES: Many hairdressers leave their profession due to health problems, including occupational hand eczema, which has been associated with skin exposure to sensitising hair dye components such as paraphenylenediamine (PPD) and paratoluenediamine (PTD). Since the use of protective gloves is advised but without the short-term effect being known, our main goal was to attribute a significant biomarker reduction to adequate glove use, in a real work situation. METHODS: 11 hairdressers were studied over 2 weeks. In the first week, they worked as usual and (re)used their gloves. Thereafter, we intervened to improve glove use during the second week. In both weeks, workplace exposure data were collected through observations, and systemic exposure was quantified by biomonitoring of PPD and PTD. The effect of improved glove use and other exposure determinants was studied through mixed models analysis. RESULTS: We showed that improved glove use significantly reduced mean PTD concentrations from 24.1 before to 4.2 µg/g creatinine after the intervention (n=11, third day postshift). In addition, mean PTD concentrations increased during the first week (14 times elevated after three consecutive shifts), but not during the second week. For PPD, no effect of improved glove use and no accumulation effect were detected. CONCLUSIONS: Our study is the first to deliver evidence for a significant reduction in systemic exposure to PTD through improved glove use. Disposable gloves should never be reused. PTD biomonitoring is shown to be a practical tool to quantify recent dermal exposure to oxidative hair dye components.

Determination of 2,5-toluylenediamine (2,5-TDA) and aromatic amines in urine after personal application of hair dyes: kinetics and doses.

The personal use of hair dye products is currently under discussion due to the potentially increased risk of bladder cancer among long-time users described in epidemiological literature. In order to investigate the dermal absorption of aromatic diamines as well as aromatic amines possibly present as contaminants in hair dye formulations, we conducted a biomonitoring study under real-life conditions and calculated kinetics and doses for the urinary excretion. Urine samples of two female subjects were collected for a time period of 48 h after personal application of a hair dye cream and analysed for aromatic diamines as well as o-toluidine and 4-aminobiphenyl using highly specific GC/MS-methods. 2,5-Toluylenediamine (2,5-TDA) as active ingredient of hair dyes is rapidly absorbed dermally. After a distribution phase of 12 h, 2,5-TDA is excreted with a half-time of 8 h. Excretion was 90% complete within 24 h after application. The doses of 2,5-TDA excreted within 48 h were 700 µg for application of a brown-reddish hair dye cream and 1.5 mg for the application of a brown-black hair dye cream. Urinary 4-aminobiphenyl as well as contaminations with other aromatic diamines were not detectable in our study. Due to the artifactual formation of o-toluidine in the presence of high concentrations of urinary 2,5-TDA, our results could not prove an increased internal exposure of humans to carcinogenic amines after personal application of hair dyes.

Factors affecting variability in the urinary biomarker 1,6-hexamethylene diamine in workers exposed to 1,6-hexamethylene diisocyanate.

Although urinary 1,6-hexamethylene diamine (HDA) is a useful biomarker of exposure to 1,6-hexamethylene diisocyanate (HDI), a large degree of unexplained intra- and inter-individual variability exists between estimated HDI exposure and urine HDA levels. We investigated the effect of individual and workplace factors on urine HDA levels using quantitative dermal and inhalation exposure data derived from a survey of automotive spray painters exposed to HDI. Painters' dermal and breathing-zone HDI-exposures were monitored over an entire workday for up to three separate workdays, spaced approximately one month apart. One urine sample was collected before the start of work with HDI-containing paints, and multiple samples were collected throughout the workday. Using mixed effects multiple linear regression modeling, coverall use resulted in significantly lower HDA levels (p = 0.12), and weekday contributed to significant variability in HDA levels (p = 0.056). We also investigated differences in urine HDA levels stratified by dichotomous and classification covariates using analysis of variance. Use of coveralls (p = 0.05), respirator type worn (p = 0.06), smoker status (p = 0.12), paint-booth type (p = 0.02), and more than one painter at the shop (p = 0.10) were all found to significantly affect urine HDA levels adjusted for creatinine concentration. Coverall use remained significant (p = 0.10), even after adjusting for respirator type. These results indicate that the variation in urine HDA level is mainly due to workplace factors and that appropriate dermal and inhalation protection is required to prevent HDI exposure.

Urine 1,6-hexamethylene diamine (HDA) levels among workers exposed to 1,6-hexamethylene diisocyanate (HDI).

Urinary 1,6-hexamethylene diamine (HDA) may serve as a biomarker for systemic exposure to 1,6-hexamethylene diisocyanate (HDI) in occupationally exposed populations. However, the quantitative relationships between dermal and inhalation exposure to HDI and urine HDA levels have not been established. We measured acid-hydrolyzed urine HDA levels along with dermal and breathing-zone levels of HDI in 48 automotive spray painters. These measurements were conducted over the course of an entire workday for up to three separate workdays that were spaced approximately 1 month apart. One urine sample was collected before the start of work with HDI-containing paints and subsequent samples were collected during the workday. HDA levels varied throughout the day and ranged from nondetectable to 65.9 microg l(-1) with a geometric mean and geometric standard deviation of 0.10 microg l(-1) +/- 6.68. Dermal exposure and inhalation exposure levels, adjusted for the type of respirator worn, were both significant predictors of urine HDA levels in the linear mixed models. Creatinine was a significant covariate when used as an independent variable along with dermal and respirator-adjusted inhalation exposure. Consequently, exposure assessment models must account for the water content of a urine sample. These findings indicate that HDA exhibits a biphasic elimination pattern, with a half-life of 2.9 h for the fast elimination phase. Our results also indicate that urine HDA level is significantly associated with systemic HDI exposure through both the skin and the lungs. We conclude that urinary HDA may be used as a biomarker of exposure to HDI, but biological monitoring should be tailored to reliably capture the intermittent exposure pattern typical in this industry.

Effect of creatinine and specific gravity normalization on urinary biomarker 1,6-hexamethylene diamine.

Urine amine levels used as biomarkers of diisocyanate exposure have usually been normalized with creatinine concentration. The suitability of using creatinine concentration or specific gravity for these biomarkers in exposure assessment has not been established. We investigated the effect of creatinine concentration and specific gravity on urine 1,6-hexamethylene diamine (HDA) levels in multiple mixed linear regression models using quantitative dermal and inhalation exposure data derived from a survey of automotive spray painters occupationally exposed to 1,6-hexamethylene diisocyanate (HDI). Painters' dermal and breathing-zone HDI exposure were monitored for an entire workday for up to three workdays spaced approximately one month apart. One urine sample was collected before the start of work with HDI-containing paints, and multiple samples were collected throughout the workday. Both creatinine concentration and specific gravity were highly significant predictors (p < 0.0001) of urine HDA levels. When these two were used together in the same model, creatinine remained highly significant (p < 0.0001), but specific gravity decreased in significance (p-values 0.10-0.17). We used different individual factors to determine which affected creatinine and specific gravity. Urine collection time was a highly significant predictor of specific gravity (p = 0.003) and creatinine concentration (p = 0.001). Smoker status was significant (p = 0.026) in the creatinine model. The findings indicate that creatinine concentration is more appropriate to account for urine water content than specific gravity and that creatinine is best used as an independent variable in HDI exposure assessment models instead of traditional urine normalization with creatinine concentration.

Indoor air pollution evaluation with emphasize on HDI and biological assessment of HDA in the polyurethane factories.

Today, many raw materials used in factories may have a dangerous effect on the physiological system of workers. One of them which is widely used in the polyurethane factories is diisocyanates. These compounds are widely used in surface coatings, polyurethane foams, adhesives, resins, elastomers, binders, and sealants. Exposure to diisocyanates causes irritation to the skin, mucous membranes, eyes, and respiratory tract. Hexamethylene diamine (HDA) is metabolite of hexamethylene diisocyanate (HDI). It is an excretory material by worker's urine who is exposed to HDI. Around 100 air samples were collected from five defined factories by midget impinger which contained dimethyl sulfoxide absorbent as a solvent and tryptamine as reagent. Samples were analyzed by high-performance liquid chromatography with EC\UV detector using NIOSH 5522 method of sampling. Also, 50 urine samples collected from workers were also analyzed using William's biological analysis method. The concentration of HDI into all air samples were more than 88 microg/m(3), and they have shown high concentration of pollutant in the workplaces in comparison with NIOSH standard, and all of the workers' urine were contaminated by HDA. The correlation and regression test were used to obtain statistical model for HDI and HDA, which is useful for the prediction of diisocyanates pollution situation in the polyurethane factories.

UPLC-ESI-MS/MS method for the quantitative measurement of aliphatic diamines, trimethylamine N-oxide, and ß-methylamino-l-alanine in human urine.

This work describes a quantitative high-throughput analytical method for the simultaneous measurement of small aliphatic nitrogenous biomarkers, i.e., 1,6-hexamethylenediamine (HDA), isophoronediamine (IPDA), ß-methylamino-l-alanine (BMAA), and trimethylamine N-oxide (TMAO), in human urine. Urinary aliphatic diamines, HDA and IPDA, are potential biomarkers of environmental exposure to their corresponding diisocyanates. Urinary BMAA forms as a result of human exposure to blue-green algae contaminated food. And, TMAO is excreted in urine due to the consumption of carnitine- and choline-rich diets. These urinary biomarkers represent classes of small aliphatic nitrogen-containing compounds (N-compounds) that have a high aqueous solubility, low logP, and/or high basic pKa. Because of the highly polar characteristics, analysis of these compounds in complex sample matrices is often challenging. We report on the development of ion-pairing chemistry based ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method for the simultaneous measurement of these biomarkers in human urine. Chromatographic separation was optimized using heptafluorobutyric acid-(HFBA-) based mobile phase and a reversed-phase C18 column. All four analytes were baseline separated within 2.6 min with an overall run time of 5 min per sample injection. Sample preparation involved 4 h of acid hydrolysis followed by automated solid phase extraction (SPE) performed using strong cation exchange sorbent bed with 7 N ammonia solution in methanol as eluent. Limits of detection ranged from 0.05 ng/mL to 1.60 ng/mL. The inter-day and intra-day accuracy were within 10%, and reproducibility within 15%. The method is accurate, fast, and well-suited for biomonitoring studies within targeted groups, as well as larger population-based studies such as the U. S. National Health and Nutrition Examination Survey (NHANES).

Exposure to Diisocyanates and Their Corresponding Diamines in Seven Different Workplaces.

Biological monitoring to assess exposure to diisocyanates in the workplace is becoming increasingly widespread due to its relative ease of use and ability to look at all exposure routes. Currently, biological monitoring measures the corresponding isocyanate-derived diamine in urine, after hydrolysis. Because of this, any exposure to the diamines themselves released during the industrial process could confound the assessment of diisocyanate exposure. This paper reports an initial assessment of the extent of diamine formation and exposure during different processes involving diisocyanates including casting, grouting, core making, spray painting, foam blowing, and floor screeding. Air monitoring and glove analysis were conducted for both the relevant diisocyanate (measured as total NCO) and its corresponding diamine; urine samples were analysed (after hydrolysis) for the isocyanate-derived diamine. Processes that generated aerosols (as demonstrated by impinger analysis) such as spray painting and foam blowing were associated with the detection of diamines. Those processes that did not generate aerosols (casting, grouting, core making, and screeding) had no diamines detected, either in air or on gloves. In spray-painting tasks, diamines were a minor component (<15%) of the ambient concentration whereas in the foam blowing processes, where water is added to the process, diamine generation is more marked (up to eight times the airborne NCO concentration). Some non-aerosol processes gave rise to substantial diamine levels in urine (in exceedance of international guidance values, >5 µmol mol-1 creatinine) despite airborne levels being well within occupational exposure limits (20 µg m-3 total NCO in Great Britain); measurement data and statistical modelling indicated that skin absorption was the most likely exposure route. Foam blowing exposures were more complex, but urinary levels were greater than those expected from diisocyanate inhalation alone (measured as total NCO). This study provides evidence that biological monitoring for diisocyanates based on measuring the corresponding diamine in urine is valid, although any co-exposure to diamines themselves should be considered when interpreting results. It also demonstrates the potential for substantial skin absorption of diisocyanates in certain processes such as floor screeding and foam production.

Pharmacokinetics of guanazole in patients with acute myelocytic leukemia.

Levels of guanazole (GZ) in plasma and packed cells were determined after a single tracer dose of 14C-guanazole or during a 5-day continuous intravenous therapeutic infusion of unlabeled drug to 5 patients with acute myelocytic leukemia (AML). The levels of unlabeled drug were determined colorimetrically. GZ infected as a tracer dose was rapidly distributed in an apparent volume of 0.61 l/kg, which is somewhat less than that of total body water, and the drug appeared to be eliminated essentially unchanged by glomerular filtration. The mean apparent volume of distribution increased by about 15% during infusion. An increase of 60% was also noted in the half-life (t1/2) values, with a concimitant decrease in the mean value of renal clearance rate by 40%, except in 1 case. The study demonstrates that monitoring levels of guanazole is possible during infusion therapy and indicates that the data could be used to evaluate pharmacokinetic parameters predicting the time-course of such levels in patients.

An enzymatic differential assay for urinary diamines, spermidine, and spermine.

Subsequent to the hydrolysis of urinary conjugated amines by heating with hydrochloric acid, free amines were isolated by cation-exchange chromatography. SPD and SPM in an aliquot of amine extract were first oxidized by PAO from Penicillium chrysogenum, producing PUT and hydrogen peroxide. DIAs, which consist of the initially present DIAs plus PUT produced by PAO, were subsequently oxidized by PUO from Micrococcus rubens, producing hydrogen peroxide. In an another aliquot of the amine extract DIAs and SPD were oxidized by PUO, producing hydrogen peroxide. Quinone dye, derived from hydrogen peroxide generated in each end-point reaction, was measured spectrophotometrically at 555 nm, and the amounts of the respective amines in urine were calculated. Significantly elevated levels of DIA, SPD, SPM, and an elevated DIA to SPD ratio were found in urine from 46 cancer patients, as compared to 34 normal control subjects. An increase in DIA and the ratio of DIA to SPD was found at clinical tumor stage I of the alimentary tract. The levels of DIA remained fairly constant and the ratio of DIA to SPD was consistently decreased with advancing clinical tumor stages. In patients who had undergone curative resection, there were greater decreasing rates (80% of cases for DIA and 80% for SPD) than in patients who had undergone noncurative resection (45.5% for DIA and 36.4% for SPD).

A new enzymatic assay for total diamines and polyamines in urine of cancer patients.

A detailed procedure of a new photometric assay for total diamines and polyamines in human urine using soybean seedling amine oxidase (SSAO) as an enzyme reagent is described. It is based on the unique substrate specificity of SSAO that the enzyme is active toward all diamines and polyamines. The amines were purified from urine by cation-exchange chromatography and incubated with SSAO. Hydrogen peroxide formed in the oxidase reaction was measured photometrically by coupling 4-aminoantipyrine with phenol in the presence of peroxidase. For its simplicity and sensitivity, our method seems useful for routine clinical investigation. The data obtained from normal subjects and patients of various cancers are presented to validate the present method.

Separation and quantification of urinary di- and polyamines by gas chromatography with electron capture detection.

A sensitive and specific gas chromatographic assay procedure employing electron capture detection has been developed for the assay of free and total di- and polyamines in human urine. Urine samples, hydrolysed with hydrochloric acid where necessary for the measurement of total amine output, were evaporated to dryness and, after the residues had been taken up in water, purified successively on Porapak Q and Dowex 50 X2 columns. Following evaporation of eluate, pentafluoropropionyl derivatives were made and analysed gas chromatographically using temperature programming. Di- and polyamines can be measured accurately at the picomole level and normal urinary output values calculated using this method agree well with those noted by other workers.

A fluorometric assay for total diamines in human urine using human placental diamine oxidase.

The detailed procedure for a new fluorometric assay for total diamines in human urine is described. The diamines were purified from the urine by cation-exchange chromatography and incubated with human placental diamine oxidase. Hydrogen peroxide formed in the diamine oxidase reaction was measured fluorometrically by converting homovanillic acid to a highly fluorescent compound in the presence of peroxidase. Because of its simplicity and high sensitivity, our present method seems useful for routine clinical investigation. The data obtained from normal subjects and patients suffering from various forms of cancer are also presented.

Urinary hexane diamine to assess respiratory exposure to hexamethylene diisocyanate aerosol: a human inhalation study.

The use of urinary hexane diamine (HDA) as a biomarker to assess human respiratory exposure to hexamethylene diisocyanate (HDI) aerosol was evaluated. Twenty-three auto body shop workers were exposed to HDI biuret aerosol for two hours using a closed exposure apparatus. HDI exposures were quantified using both a direct-reading instrument and a treated-filter method. Urine samples collected at baseline, immediately post exposure, and every four to five hours for up to 20 hours were analyzed for HDA using gas chromatography and mass spectrometry. Mean urinary HDA (microg/g creatinine) sharply increased from the baseline value of 0.7 to 18.1 immediately post exposure and decreased rapidly to 4.7, 1.9 and 1.1, respectively, at 4, 9, and 18 hours post exposure. Considerable individual variability was found. Urinary HDA can assess acute respiratory exposure to HDI aerosol, but may have limited use as a biomarker of exposure in the workplace.

[Detection of urinary polyamine by a new enzymatic differential assay. (I). Fundamental study on a new enzymatic differential assay].

A new enzymatic method for determining urinary polyamine concentration by fractionation of the urinary acetyl conjugate into free polyamines with acylpolyamine amido-hydrolase and quantification using two kinds of amine-oxidase of different substrate specificity was examined. High recovery rates of urinary polyamine by enzymatic hydrolyzation were obtained, namely, 95 +/- 4% for diamine, 95 +/- 1% for spermidine and 99 +/- 2% for spermine. Furthermore, excellent linearity was demonstrated with up to 150 mumole/l diamine, up to 75 mumole/l spermidine and up to 50 mumole/l spermine. Although urinary polyamine concentration varied diurnally even after correction of urinary creatinine, day-to-day variation disappeared. In 24-hour pooled urine and voluntary urine, diamine, spermidine and spermine correlated relatively well. Urinary leukocytes and erythrocytes exerted no influence on urinary polyamine.

[Detection of urinary polyamine by a new enzymatic differential assay. (II). Comparison with conventional method].

A new method of determining urinary polyamine concentration was compared with other techniques, namely, high pressure liquid chromatography (HPLC) and a polyamine test-enzyme kit. The values obtained by the new method, HPLC, and polyamine test-enzyme kit correlated well for all the fractions: diamine, spermidine and spermine. The correlation between the new method and the polyamine test-enzyme kit gave r = 0.9702, y = 1.1359x + 5.1266 (n = 48).

[Detection of urinary polyamine by a new enzymatic differential assay. (III). Studies on urinary polyamines in patients with malignant genitourinary diseases].

A new enzymatic method for isolation and determination of urinary polyamines was presented and basically studied in previous report 1 and 2 in comparison with existing techniques. Using the new method, urinary polyamines were isolated and determined in 56 patients with genitourinary cancer. Urinary polyamines were also determined in 63 controls consisting of 20 normal subjects, 25 patients with benign urological disease and 18 patients with BPH. The mean concentrations of Diamine, Spermidine, Spermine in 20 normal subjects were 16.6 +/- 5.8 mumoles/g Cr, 4.7 +/- 2.0 mumoles/g Cr and 0.99 +/- 0.51 mumoles/g Cr respectively. To emphasize the specificity to cancer, the level of positiveness was modified to a higher value than M+3SD. The positive values thus calculated were 40 mumoles/g Cr for Diamine, 15 mumoles/g Cr for Spermidine and 3 mumoles/g Cr for Spermine. The positive ratios of Diamine in patients with early cancer were 43% in renal cell cancer, 20% in pelvic and ureter cancer, 0% in bladder cancer and 20% in prostatic cancer. Those of Spermidine were 29% in renal cell cancer, 0% in pelvic and ureter cancer, 20% in bladder cancer and 40% in prostatic cancer. Those of Spermine were 29% in renal cell cancer, 20% in pelvic and ureter cancer, 20% in bladder cancer and 0% in prostatic cancer. In early diagnoses, Diamine indicated high positive ratios to renal cell cancer and Spermidine to prostatic cancer. Relatively high positive ratios were demonstrated, when any one of the isolated polyamines was found positive: namely, 57% in renal cell cancer, 20% in pelvic and ureter cancer, 30% in bladder cancer and 40% in prostatic cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

[Urine polyamine in patients with malignant urological diseases using a polyamine-test enzyme kit].

Using a polyamine-test enzyme kit, the urine polyamine concentration was determined in 74 patients with malignant urological disease (12 with renal cell cancer, 13 with pelvic-ureter cancer, 24 with bladder cancer and 25 with prostate cancer), 7 patients with BPH, 20 patients with benign urological disease and 20 normal subjects. The urine polyamine level was significantly elevated in all the patients with any malignant urological disease compared to normal subjects. It was also significantly high in the patients with BPH. Defining the mean +/- 3SD (= 50 mumole/g Cr.) of 20 normal subjects as an upper limit, slightly higher levels not exceeding 100 mumol/g Cr. were frequently observed in the patients with BPH or with benign urological disease. Setting the upper limit at 100 mumole/g Cr., the positive rate amounted to 33% (low stage 17%) in renal cell cancer, 23% (low stage 14%) in pelvic ureter cancer, 13% (low stage 0%) in bladder cancer and 4% (low stage 0%) in prostate cancer. The positive rate was low especially in low stage cases.