title: [Determination of cyanamide in workplace air by high-performance liquid chromatography].
abstract: OBJECTIVE
  To establish a method for determining cyanamide in workplace air by high-performance liquid chromatography (HPLC).
  
  
  METHODS
  Air samples were collected from the workplace using the shock absorption tube containing water solution at a rate of 2.8∼3.0 ml/min for 60 min; dansyl chloride was used as a derivatization reagent to conduct pre-column derivatization, and the procedure was as follows: acetone solution (2.5 ml), mixed solution (1.0 ml) containing 0.016 mol/L Na2CO3 and 0.184 mol/L NaHCO3, and 10 mg/ml acetone solution of dansyl chloride (0.5 ml) were added into the samples, and reaction proceeded in a water bath (50 °C) for 1 h. HPLC was performed on an ODS C18 column (250 mm × 4.6 mm, 5 üm) with a mobile phase of acetonitrile-phosphate buffer (35:65) at a flow rate of 1.0 ml/min and a column temperature of 25°C; a fluorescence detector was used at an excitation wavelength of 360 nm and an emission wavelength of 495 nm.
  
  
  RESULTS
  The minimum detectable concentration of cyanamide was 0.05 üg/ml; a good linear relationship was noted when the concentration of cyanamide was 0.2∼100.0 üg/ml; the intraday relative standard deviation (RSD) was 0.28%∼1.18%, and the interday RSD was 0.22∼2.16%; the recovery rate was 95.7%∼103.0%, and the sampling efficiency was 95.8%∼96.9%. Water solution of cyanamide (pH<6.5) could be stable in the dark at room temperature for 7 d.
  
  
  CONCLUSIONS
  This method is stable, reliable, easy to operate, and highly sensitive and suitable for determination of cyanamide in workplace air.
authors.affiliation: Central laboratory, School of Public Health, Hebei United University, Tangshan 063000, China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Central laboratory, School of Public Health, Hebei United University, Tangshan 063000, China.
authors.forename: Qingzhao
authors.initials: Q
authors.lastname: Li
authors.affiliation: Central laboratory, School of Public Health, Hebei United University, Tangshan 063000, China.
authors.forename: Guoying
authors.initials: G
authors.lastname: Zheng
authors.affiliation: Central laboratory, School of Public Health, Hebei United University, Tangshan 063000, China.
authors.forename: Weijun
authors.initials: W
authors.lastname: Guan
authors.affiliation: Central laboratory, School of Public Health, Hebei United University, Tangshan 063000, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Central laboratory, School of Public Health, Hebei United University, Tangshan 063000, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ma
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003484:Cyanamide / Q000032:analysis*; D016273:Occupational Exposure / Q000032:analysis*; D017132:Workplace
chemical_list: D000393:Air Pollutants; D003484:Cyanamide