Cyclophosphamide. Determination method in workplace air

Abstract

Cyclophosphamide (CP) at room temperature is a fine white crystalline odorless powder. It is used mainly as a cytostatic drug in anticancer therapy. Acute exposure to CP can cause bone marrow damage, hemorrhagic cystitis and cardiomyopathy. Cyclophosphamide has a negative influence on reproducibility in humans. International Agency for Research on Cancer (IARC) has classified CP as carcinogenic to humans (Group 1). In the European Union, cyclophosphamide has been classified as carcinogenic category 1.A and mutagenic category 2.B. Occupational exposure to CP may occur during its production and during preparation and application of CP in oncology wards. Cyclophosphamide may be absorbed mainly by inhalation or skin contact. The aim of this study was to develop and validate a sensitive method for determining cyclophosphamide concentrations in workplace air in the range from 1/10 to 2 MAC values, in accordance with the requirements of Standard No. PN-EN 482. The study was performed using a liquid chromatograph with a tandem mass detection (HPLC-MS/MS). All chromatographic analyses were performed with Supelcosil LC 18 150 × 3 mm analytical column, which was eluted with a mixture of methanol and water with 0.1% of formic acid. The method was based on collecting CP on glass fiber filter, extracting with a mixture of methanol: water with addition of formic acid (0.1%), and chromatographic determining of resulted solution with HPLC-MS/MS technique. The average extraction efficiency of CP from filters was 90%. The method was linear (r = 0.999) within the investigated working range 0.01–0.5 μg/ml. The calculated limit of detection (LOD) and the limit of quantification (LOQ) were 0.00046 and 0.0015 μg/ml, respectively. The analytical method described in this paper, thanks to HPLC MS/MS technique, enables specific and selective determination of CP in workplace air in the presence of other compounds at concentrations from 0.0004 mg/m3 (1/25 proposed MAC value). The method precise, accurate and it meets the criteria for measuring chemical agents listed in Standard No. PN-EN 482. The method can be used for assessing occupational exposure to CP and associated risk to workers’ health. The developed method of determining CP has been recorded as an analytical procedure (see appendix).