Quantitation of lower levels of the DNA adduct of thymidylyl(3'-5')thymidine methyl phosphotriester by liquid chromatography/negative atmospheric pressure chemical ionization tandem mass spectrometry.
A sensitive method has been developed for the direct quantitation of the methyl phosphotriester DNA adduct of thymidyl(3'-5')thymidine (dTp(Me)dT) from enzymatic DNA hydrolysates prepared from cultured cells treated with low levels of N-methyl-N-nitrosourea (MNU) and methyl methane sulfonate (MMS), by rapid and selective liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry (LC/APCI-MS/MS). The lower limit of quantitation was 0.1 ng/mL (6.4 adducts per 10(8) nucleotides). Linearity of the calibration curve was greater than 0.999 from 0.1 to 50 ng/mL. Intra-day precision for three levels of quality control samples ranged from 4.27 to 15.62%. Interday precision ranged from 2.46 to 11.95%. Using this method, the levels of dTp(Me)dT in DNA enzymatic hydrolysates obtained from a series of incubations of mouse lymphoma cells with low doses of MNU (50 microM) were quantified.
Zhang
Fagen
F
Toxicology and Environmental Research & Consulting, The Dow Chemical Company, 1803 Building, Midland, MI 48674, USA. fzzhang@dow.com
Bartels
Michael J
MJ
Pottenger
Lynn H
LH
Gollapudi
B Bhaskar
BB
Schisler
Melissa R
MR
D000818:Animals; D001274:Atmospheric Pressure; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D018736:DNA Adducts / Q000737:chemistry*; D004273:DNA, Neoplasm / Q000737:chemistry*; D015226:Dinucleoside Phosphates / Q000737:chemistry*; D008223:Lymphoma / Q000235:genetics*; D051379:Mice; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D018736:DNA Adducts; D004273:DNA, Neoplasm; D015226:Dinucleoside Phosphates; C013303:thymidylyl-(3'-5')-thymidine methyl phosphotriester