Objective: To establish a method for the determination of methyl isobutyl ketone (MIBK) in urine samples by headspace-gas chromatography-mass spectrometry. Methods: Automatic headspace sampling technique was adopted to optimize the headspace conditions (headspace bottle heating temperature and equilibration time) and gas chromatographic conditions. A total of 5 ml samples were taken and added with 3.0 g ammonium sulfate into a 20 ml headspace bottle. After heated at 60 ℃ for 30 mins, gas from the upper part of headspace bottle was injected into gas chromatography with an injection volume of 100 μl. The target was separated by HP-5MS UI (30 m×0.25 mm×0.25 μm) capillary column and then detected by mass spectrometry detector. The retention time and external standard method were used for qualitative and quantitative analysis of MIBK in samples, respectively. Results: The standard curve of MIBK showed significant linearity between 20.0-1 000.0 μg/L. The standard curve was y=62.9x-652.5, and the correlation coefficient r=0.9998. The detection limit of MIBK was 5.0 μg/L and the quantification limit of MIBK was 16.0 μg/L. The average recovery rate was 95.3%~100.2% at three spiked concentrations of low (50.0 μg/L) , medium (200.0 μg/L) and high (500.0 μg/L) . The intra-day and inter-day precisions were 1.7%~3.8% (n=6) and 1.2%~4.0% (n=6) respectively. This method was stable for the determination of MIBK, and the urine could be kept 14 d at -20 ℃ without significantly loss. Conclusion: This method is proved to be simple, practical and highly sensitive. It can satisfy the request for the determination of urine samples of workers exposed to MIBK.
Gas Chromatography-Mass Spectrometry ; Humans ; Methyl n-Butyl Ketone

OBJECTIVES: The purpose of this study is to evaluate the tire manufacturing work environments extensively and to identify workers' exposure to hazardous substances in various work processes. METHODS: Personal air sampling was conducted to measure polycyclic aromatic hydrocarbons, carbon disulfide, 1,3-butadiene, styrene, methyl isobutyl ketone, methylcyclohexane, formaldehyde, sulfur dioxide, and rubber fume in tire manufacturing plants using the National Institute for Occupational Safety Health Manual of Analytical Methods. Noise, carbon monoxide, and heat stress exposure were evaluated using direct reading instruments. Past concentrations of rubber fume were assessed using regression analysis of total particulate data from 2003 to 2007, after identifying the correlation between the concentration of total particulate and rubber fume. RESULTS: Workers were exposed to rubber fume that exceeded 0.6 mg/m3, the maximum exposure limit of the UK, in curing and production management processes. Forty-seven percent of workers were exposed to noise levels exceeding 85 dBA. Workers in the production management process were exposed to 28.1degrees C (wet bulb globe temperature value, WBGT value) even when the outdoor atmosphere was 2.7degrees C (WBGT value). Exposures to other substances were below the limit of detection or under a tenth of the threshold limit values given by the American Conference of Governmental Industrial Hygienists. CONCLUSION: To better classify exposure groups and to improve work environments, examining closely at rubber fume components and temperature as risk indicators in tire manufacturing is recommended.
Aerosols ; Atmosphere ; Butadienes ; Carbon Disulfide ; Carbon Monoxide ; Cyclohexanes ; Formaldehyde ; Hazardous Substances ; Hot Temperature ; Humans ; Limit of Detection ; Methyl n-Butyl Ketone ; Noise ; Occupational Exposure ; Occupational Health ; Polycyclic Hydrocarbons, Aromatic ; Rubber ; Styrene ; Sulfur Dioxide ; Threshold Limit Values

Organic solvents are hydrocarbon-based substances that dissolve another substance. Organic solvents are usually lipid soluble, volatile and commonly used for painting, printing, degreasing, cleaning, thinning and extraction. Due to their volatility and lipid solubility, organic solvents are easily absorbed across the alveolar-capillary membrane and through the skin. Because organic solvents are lipophilic, they tend to be distributed to lipid-rich tissue, such as adipose tissue, nervous system and liver. Almost all organic solvent can induce skin diseases such as acute irritant dermatitis and chronic eczema. Some organic solvents are associated with allergic contact dermatitis. General and nonspecific central nervous system depression is another common toxic effect induced by most organic solvents. It shows symptoms which are the same as those from alcohol drinking, and those symptoms are completely resolved by removal from exposure to solvents. Long term and repeated exposures to organic solvents can also lead to chronic adverse neurobehavioral effects. These effects are also called as chronic toxic encephalopathy, chronic solvent intoxication and psycho-organic syndrome, and commonly reported symptoms of them are headache, depression, anxiety, and impairment of recent memory. Organic brain lesions can be found in workers suffering from psycho-organic syndrome, and in this case, there is a possibility of persistent disabilities. Carbon disulfide, n-hexane, and methyl n-butyl ketone are specifically toxic to the peripheral nervous system, and cause a symmetric ascending sensory and motor polyneuropathy. Halogenated hydrocarbons including carbon tetrachloride show toxic effects on the heart, liver, kidney, and blood. Toluene can sensitize the heart to arrhythmogenic effects of epinephrine, so sudden death in young and healthy people can be ensued from glue sniffing. Benzene is able to induce any type of leukemia, especially in victims with benzene-associated aplastic anemia. Exposure to some solvents during pregnancy has potential to induce congenital malformation and spontaneous abortion. In the treatment of diseases by organic solvents, the first step should be removal from exposure to the causative solvent.
Abortion, Spontaneous ; Adipose Tissue ; Alcohol Drinking ; Anemia, Aplastic ; Anxiety ; Benzene ; Brain ; Carbon Disulfide ; Carbon Tetrachloride ; Central Nervous System ; Death, Sudden ; Depression ; Dermatitis ; Dermatitis, Allergic Contact ; Dermatitis, Irritant ; Eczema ; Epinephrine ; Female ; Headache ; Heart ; Hexanes ; Humans ; Hydrocarbons, Halogenated ; Inhalant Abuse ; Kidney ; Leukemia ; Liver ; Membranes ; Memory ; Methyl n-Butyl Ketone ; Nervous System ; Neurotoxicity Syndromes ; Occupational Diseases ; Paint ; Paintings ; Peripheral Nervous System ; Polyneuropathies ; Pregnancy ; Resin Cements ; Skin ; Skin Diseases ; Solubility ; Solvents ; Stress, Psychological ; Toluene ; Volatilization