Determination of a yellow rice toxin, luteoskyrin, in rice by using liquid chromatography-tandem mass spectrometry with electrospray ionization.
Penicillium islandicum produces luteoskyrin (LUT), a yellow rice toxin that has been found frequently in rice. However, conventional analytical methods for determining LUT are limited, are complicated, and exhibit low sensitivity. In this study, an analytical method more sensitive and simple based on high-performance liquid chromatography combined with electrospray ionization mass spectrometry was developed. The cleanup procedure of the method was one step, using a solid-phase extraction cartridge. An isocratic mobile-phase system, consisting of acetonitrile-water-acetic acid (50:49:1 [vol/vol/vol]) at a flow rate of 0.2 ml/min, was utilized to obtain the best resolution. Our method showed good linearity (r = 0.9993, 0.5 to 50 ng/g) and high repeatability (relative standard deviation = 8.9 and 5.1% at levels of 0.5 and 10 ng/g, respectively) in the fortification test. The detection and quantification limits for the method in multiple-reaction monitoring mode were 0.1 and 0.3 ng/g, respectively. The average recovery of LUT in spiked rice at 0.5 and 10 ng/g was 80.7 and 85.2%, respectively. The method developed in this study should be applicable to survey LUT in rice, with high sensitivity, selectivity, and rapidity.
Mizutani
Kohei
K
Analytical Technology Laboratory, Asahi Breweries, Ltd., 1-1-21 Midori, Moriya-shi, Ibaraki 302-0106, Japan.
Kumagai
Susumu
S
Mochizuki
Naoki
N
Kitagawa
Yasushi
Y
Sugita-Konishi
Yoshiko
Y
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D009285:Naphthoquinones / Q000032:analysis*; D012275:Oryza / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D009285:Naphthoquinones; C100224:luteoskyrin