1
|
Rosser SPA, McLachlan AJ, Hempel G, Chung J, Shaw PJ, Keogh SJ, Nath CE. Validation of a liquid chromatography-tandem mass spectrometry method for simultaneous quantification of N,N-dimethylacetamide and N-monomethylacetamide in pediatric plasma. J Sep Sci 2023; 46:e2201003. [PMID: 36879545 DOI: 10.1002/jssc.202201003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/07/2023] [Accepted: 03/04/2023] [Indexed: 03/08/2023]
Abstract
N,Na-dimethylacetamide is an excipient used in intravenous busulfan formulations, a drug used in hematopoietic stem cell transplantation conditioning. The aim of this study was to develop and validate a liquid chromatography-tandem mass spectrometry method for simultaneous quantification of N,N-dimethylacetamide, and its metabolite N-monomethylacetamide in plasma from children receiving busulfan. A 4 μl aliquot of patient plasma was extracted using 196 μl 50% methanol solution and quantified against calibrators prepared in the extraction solvent given negligible matrix effects across three concentrations. 9 [H2 ]-N,N-dimethylacetamide was used as an internal standard. Separation of N,N-dimethylacetamide and N-monomethylacetamide was achieved using a Kinetex EVO C18 stationary phase (100 mm × 2.1 mm × 2.6 μm) running an isocratic mobile phase of 30% methanol containing 0.1% formic acid at a flow of 0.2 ml/min over 3.0 min. The injection volume was 1 μl. Calibration curves for N,N-dimethylacetamide and N-monomethylacetamide were linear up to 1200 and 200 μg/L, respectively, with a lower limit of quantification 1 μg/L for both analytes. Calibrator accuracy and precision were within ± 10% of the test parameters across four concentration levels. Analytes were stable over 14 days at three different storage conditions. This method was successfully applied to measure N,N-dimethylacetamide and N-monomethylacetamide concentrations in a total of 1265 plasma samples from 77 children.
Collapse
Affiliation(s)
- Sebastian P A Rosser
- The Children's Hospital at Westmead Clinical School, University of Sydney, Sydney, Australia.,Department of Biochemistry, The Children's Hospital at Westmead, Sydney, Australia.,Cancer Centre for Children, The Children's Hospital at Westmead, Sydney, Australia
| | - Andrew J McLachlan
- Sydney Pharmacy School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Georg Hempel
- Institute for Pharmaceutical and Medicinal Chemistry and Clinical Pharmacy, University of Münster, Sydney, Germany
| | - Jason Chung
- The Children's Hospital at Westmead Clinical School, University of Sydney, Sydney, Australia.,Department of Biochemistry, The Children's Hospital at Westmead, Sydney, Australia
| | - Peter J Shaw
- The Children's Hospital at Westmead Clinical School, University of Sydney, Sydney, Australia.,Cancer Centre for Children, The Children's Hospital at Westmead, Sydney, Australia
| | - Steven J Keogh
- Cancer Centre for Children, The Children's Hospital at Westmead, Sydney, Australia
| | - Christa E Nath
- Department of Biochemistry, The Children's Hospital at Westmead, Sydney, Australia.,Cancer Centre for Children, The Children's Hospital at Westmead, Sydney, Australia.,Sydney Pharmacy School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| |
Collapse
|
2
|
Yamamoto S, Matsumoto A, Yui Y, Miyazaki S, Kumagai S, Hori H, Ichiba M. Concentration determination of urinary metabolites of N,N-dimethylacetamide by high-performance liquid chromatography-tandem mass spectrometry. J Occup Health 2018; 60:140-147. [PMID: 29213009 PMCID: PMC5886881 DOI: 10.1539/joh.17-0098-oa] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 11/08/2017] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVES N,N-Dimethylacetamide (DMAC) is widely used in industry as a solvent. It can be absorbed through human skin. Therefore, it is necessary to determine exposure to DMAC via biological monitoring. However, the precision of traditional gas chromatography (GC) is low due to the thermal decomposition of metabolites in the high-temperature GC injection port. To overcome this problem, we have developed a new method for the simultaneous separation and quantification of urinary DMAC metabolites using liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS Urine samples were diluted 10-fold in formic acid, and 1-μl aliquots were injected into the LC-MS/MS equipment. A C18 reverse-phase Octa Decyl Silyl (ODS) column was used as the analytical column, and the mobile phase consisted of a mixture of methanol and aqueous formic acid solution. RESULTS Urinary concentrations of DMAC and its known metabolites (N-hydroxymethyl-N-methylacetamide (DMAC-OH), N-methylacetamide (NMAC), and S- (acetamidomethyl) mercapturic acid (AMMA) ) were determined in a single run. The dynamic ranges of the calibration curves were 0.05-5 mg/l (r≥0.999) for all four compounds. The limits of detection for DMAC, DMAC-OH, NMAC, and AMMA in urine were 0.04, 0.02, 0.05, and 0.02 mg/l, respectively. Within-run accuracies were 96.5%-109.6% with relative standard deviations of precision being 3.43%-10.31%. CONCLUSIONS The results demonstrated that the proposed method could successfully quantify low concentrations of DMAC and its metabolites with high precision. Hence, this method is useful for evaluating DMAC exposure. In addition, this method can be used to examine metabolite behaviors in human bodies after exposure and to select appropriate biomarkers.
Collapse
Affiliation(s)
- Shinobu Yamamoto
- Department of Environmental Measurement and Control, University of Occupational and Environmental Health
- Department of Social Medicine, Saga University
| | | | | | | | - Shinji Kumagai
- Department of Occupational and Environmental Management, University of Occupational and Environmental Health
| | - Hajime Hori
- Department of Environmental Measurement and Control, University of Occupational and Environmental Health
| | | |
Collapse
|
3
|
MIYAUCHI H, TSUDA Y, MINOZOE A, TANAKA S, ARITO H, TSUKAHARA T, NOMIYAMA T. Occupational exposure to N,N-dimethylformamide in the summer and winter. INDUSTRIAL HEALTH 2014; 52:512-20. [PMID: 25224331 PMCID: PMC4273019 DOI: 10.2486/indhealth.2014-0070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 07/16/2014] [Indexed: 05/26/2023]
Abstract
We evaluated total body burden of N,N-dimethylformamide (DMF) taken through the lung and skin by personal exposure of workers to DMF and urinalysis of N-methylformamide (NMF) and N-acetyl-S(N-methylcarbamoyl)-cysteine (AMCC). A total of 270 workers were engaged in four different jobs in a workplace distant from main production lines emanating high levels of DMF. They were not required to wear any personal protective equipment including respirators or gloves. We found that log-transformed urinary levels of NMF and AMCC increased with an increase in log-transformed concentrations of exposure to DMF. Urinary levels of NMF and AMCC were significantly higher in the summer than the winter, although there was no significant seasonal difference in the concentrations of exposure to DMF. Our findings suggested that the increased urinary levels of NMF and AMCC in the summer resulted in increased skin absorption of DMF due to an increased amount of DMF absorbed by the moisturized skin under humid and hot conditions. Seasonal changes in the relative internal exposure index confirmed the present finding of enhanced summertime skin absorption of DMF. AMCC is thought to be a useful biomarker for assessments of cumulative exposure to DMF over a workweek and for evaluations of workers' health effects.
Collapse
Affiliation(s)
| | - Yoko TSUDA
- Department of Preventive Medicine and Public Health, Shinshu
University School of Medicine, Japan
| | | | - Shigeru TANAKA
- Department of Public Health, Graduate School of Human Life
Science, Jumonji University, Japan
| | - Heihachiro ARITO
- Occupational Health Research and Development Center, Japan
Industrial Safety and Health Association, Japan
| | - Teruomi TSUKAHARA
- Department of Preventive Medicine and Public Health, Shinshu
University School of Medicine, Japan
| | - Tetsuo NOMIYAMA
- Department of Preventive Medicine and Public Health, Shinshu
University School of Medicine, Japan
| |
Collapse
|
4
|
Tsuda Y, Miyauchi H, Minozoe A, Tanaka S, Arito H, Tsukahara T, Nomiyama T. Seasonal difference in percutaneous absorption of N,N-dimethylformamide as determined using two urinary metabolites. J Occup Health 2014; 56:252-9. [PMID: 24826962 DOI: 10.1539/joh.13-0228-oa] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE We evaluated the percutaneous absorption of N,N-dimethylformamide (DMF) in DMF-exposed workers in the summer and winter by assessing their urinary levels of DMF metabolites. METHODS Breathing-zone concentrations of DMF and workers' urinary levels of N-methylformamide (NMF) and N-acetyl-S-(N-methylcarbamoyl)-cysteine (AMCC) were simultaneously measured in the summer and winter in 193 male workers wearing a respirator and chemical protective gloves. RESULTS The mean breathing-zone concentrations of DMF in both seasons were below the occupational exposure limit of 10 ppm. Although there was no significant seasonal difference in the breathing-zone concentrations of DMF, workers' urinary levels of NMF and AMCC were significantly higher in the summer than in the winter. Log-transformed urinary levels of the metabolites were significantly correlated with log-transformed breathing-zone concentrations of DMF in the summer, whereas no significant correlation between AMCC and DMF was found in the winter. The urinary levels of AMCC were dispersed more widely than those of NMF, suggesting that urinary AMCC reflected the cumulative exposure to DMF over a workweek. CONCLUSIONS Percutaneous absorption was the principal route of exposure to DMF for the respirator-wearing workers. Increased urinary levels of NMF and AMCC in the summer were attributed to increased percutaneous absorption of DMF resulting from the increased amount of water-soluble DMF absorbed by sweaty skin caused by the increased summertime room temperature and humidity.
Collapse
Affiliation(s)
- Yoko Tsuda
- Department of Preventive Medicine and Public Health, Shinshu University School of Medicine
| | | | | | | | | | | | | |
Collapse
|
5
|
Kennedy GL. Toxicology of dimethyl and monomethyl derivatives of acetamide and formamide: a second update. Crit Rev Toxicol 2012; 42:793-826. [DOI: 10.3109/10408444.2012.725028] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
6
|
Jung SJ, Lee CY, Kim SA, Park KS, Ha BG, Kim J, Yu JY, Choi T. Dimethylacetamide-induced hepatic injuries among spandex fibre workers. Clin Toxicol (Phila) 2008; 45:435-9. [PMID: 17503240 DOI: 10.1080/15563650601117897] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVES To investigate clinical features of dimethylacetamide-induced hepatic injuries (DIHIs). METHODS Workers exposed to dimethylacetamide (DMAc) in two spandex factories were monitored for DIHI. We identified 38 DIHI cases as study subjects between 2001 and 2004. DMAc exposure was estimated with urinary N-methylacetamide (NMAc) results from 2003 to 2004. RESULTS All 38 cases showed hepatocellular-type liver injury. The interval between first exposure and identification of hepatic injury (latent period) was mostly less than two months and never exceeded six months. In addition, three repeat DIHI cases showed much shorter latent periods for recurrence than their initial latent periods of hepatic injury. A 50% decline of serum alanine aminotransferase (ALT) levels after the cessation of DMAc exposure took less than 14 days and a 90% decline less than 31 days. The median urinary NMAc level of DIHI group (samples from the department of DIHI cases) was 25.1 mg/g Cr; higher than that of all other urinary NMAc results (11.8 mg/g Cr). CONCLUSIONS Our data suggest that DMAc can induce hepatocellular-type liver injury and the mechanism of DIHI may be idiosyncratic. Although our exposure estimation was incomplete, the workers with DIHIs might be exposed to higher levels of environmental DMAc than the workers who did not develop DIHIs. All workers exposed to DMAc need to be closely observed for occurrence of hepatic injury for at least six months.
Collapse
Affiliation(s)
- Sang-Jae Jung
- Department of Occupational and Environmental Medicine, Gumi CHA Medical Center, College of Medicine, Pochon CHA University, Gumi, South Korea
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Oechtering D, Boos J, Hempel G. Monitoring of N,N-dimethylacetamide in children during i.v.-busulfan therapy by liquid chromatography-mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 838:129-34. [PMID: 16725388 DOI: 10.1016/j.jchromb.2006.04.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Revised: 04/18/2006] [Accepted: 04/21/2006] [Indexed: 11/19/2022]
Abstract
Recently, an intravenous (i.v.) formulation of busulfan using the potentially hepatotoxic and neurotoxic N,N-dimethylacetamide (DMA) as a solvent was introduced. There is a need to assess the exposure of DMA in patients during the intravenous high dose therapy. A rapid and selective LC-MS method was developed to quantify relevant DMA concentration in plasma. After protein precipitation with trichloroacetic acid, the isocratic separation was achieved using a 150 mm x 2 mm C18 column and elution with a mobile phase containing 0.1% formic acid in water/acetonitrile (97:3). Detection of DMA was carried out with a ThermoFinnigan single-quadrupole mass spectrometer in selected-ion monitoring mode as H+ -adduct at m/z 88.2. Deuterium-labelled DMA was used as the internal standard. The LC-MS method was accurate, precise and reproducible in the range from 0.25 to 150 mg/l and met the generally accepted criteria for bioanalytical methods. Two calibration ranges from 0.25 to 7.5 mg/l and 7.5 to 150 mg/l were used. The intra- (n = 7) and interassay (n = 7) accuracy and precision were both < 7.7% and the limit of quantification is 0.25 mg/l. The method was successfully applied to investigate 203 plasma samples in children during the i.v.-busulfan therapy.
Collapse
Affiliation(s)
- Doris Oechtering
- Klinik und Poliklinik für Kinder- und Jugendmedizin, Pädiatrische Hämatologie/Onkologie, Albert-Schweitzer-Str. 33, 48129 Muenster, Germany
| | | | | |
Collapse
|
8
|
Tolando R, Zanovello A, Ferrara R, Iley JN, Manno M. Inactivation of rat liver cytochrome P450 (P450) by N,N-dimethylformamide and N,N-dimethylacetamide. Toxicol Lett 2001; 124:101-11. [PMID: 11684362 DOI: 10.1016/s0378-4274(01)00384-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
N,N-dimethylformamide (DMF), an organic solvent widely used in industry, is bioactivated by cytochrome P450 (P450) to reactive metabolites which are believed to be responsible for the hepatotoxicity observed in animals and humans. A decrease of the activating enzyme has been reported in rats treated with DMF, although the specific P450 isoform(s) involved and the nature of the reactive species responsible for this and the other toxic effects are still being investigated. In the present work, the effect of DMF and of the structurally related N,N-dimethylacetamide (DMAc) on the activating enzyme and the nature of the reactive species involved in the mechanism of P450 inactivation by the two chemicals were investigated in vitro. Incubation of liver microsomes from pyridine-induced rats with either substrate resulted in a dose-dependent (0-20 mM) loss of P450 (up to 28 and 24% for DMF and DMAc, respectively), microsomal haem (up to 24 and 20% for DMF and DMAc, respectively), but not protoporphyrin IX content. Moreover, bubbling of CO through the incubation mixture gave almost complete protection against substrate-dependent P450 inactivation, and the spin trapping agent N-tert-butyl-alpha-phenylnitrone, but neither glutathione nor vitamin C, provided a significant protection against DMF- or DMAc-dependent haem loss. Finally, electron spin resonance analysis of microsomal incubations in presence of DMF or DMAc showed spectral evidence for a carbon centered radical intermediate. The results indicate, overall, that both compounds are metabolized in vitro by P450, probably CYP2E1, to free radical metabolites which attack the haem prosthetic group, leading to suicidal enzyme inactivation.
Collapse
Affiliation(s)
- R Tolando
- Institute of Occupational Medicine, University of Padua, Via Facciolati, 71, Padua 35128, Italy
| | | | | | | | | |
Collapse
|