- 作者：Chia-Chu Liu ; Chia-Fang Wu ; Jentaie Shiea ; Yi-Tzu Cho ; Tusty-Jiuan Hsieh ; Yii-Her Chou ; Bai-Hsiun Chen ; Shu-Pin Huang ; Wen-Jeng Wu ; Jung-Tsung Shen ; Mei-Yu Chang ; Chun-Hsiung Huang ; Ai-Wen Chang ; Ming-Tsang Wu
- 关键词：Melamine ; Urolithiasis ; MALDI-TOF MS ; Infrared spectroscopy
- 刊名：Clinica Chimica Acta
- 出版年：2012
- 出版时间：9 October, 2012
- 年：2012
- 卷：413
- 期：19-20
- 页码：1689-1695
- 全文大小：911 K
Background
The link between melamine-contaminated daily foodstuffs and urolithiasis formation has drawn an international concern. However, detection of melamine levels in urine may not completely represent external melamine exposure. Thus, finding an additional analytical method for the study of environmental melamine exposure and its adverse effect in humans is crucial.Methods
Eleven adult patients diagnosed with uric acid urolithiasis were retrospectively analyzed. Melamine levels in their overnight one-spot urine samples were measured by a triple quadrupole liquid chromatography tandem mass spectrometry (LC-MS/MS). The compositions of stone samples were analyzed by the Fourier transform infrared (FTIR) spectrophotometer and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).
Results
Seven (63.6 % ) out of 11 patients had detectable melamine levels in their urine specimens (method of detection limit: 0.8 ng/ml). Three patients (27.3 % ) were highly suspected of having melamine-containing urolithiasis in FTIR spectra. In one of those three cases who still had available stored stone specimens, MALDI-TOF MS further confirmed melamine components in this male patient's stone specimens. In contrast, his urinary melamine level was below the detection limit by LC-MS/MS.
Conclusions
Direct analysis of melamine in the composition of urolithiasis by MALDI-TOF MS can be an additional analytical method to evaluate for external melamine exposure.