Impurity profiling and classification of seized methamphetamine may play an important role in the... more Impurity profiling and classification of seized methamphetamine may play an important role in the interpretation of analytical results, the determination of the synthetic method employed, and the criminal investigations of drug traffic routes. Our study is focused on classifying seized methamphetamine samples according to the groups sorted by the types and quantities of impurities present in illicit methamphetamine samples. The samples (100mg) were dissolved in 2 mL of potassium phosphate buffer (pH 7.0), extracted with 200 microL of ethyl acetate under basic condition, and then analyzed by gas chromatography-mass spectrometry (GC-MS) with a DB-1 capillary column (30 m x 0.25 mm i.d., 0.25 microm). Five impurities are used as criteria for the classification of seized methamphetamine samples by Emde and Nagai method. A total of fifty-two samples of seized methamphetamine were analyzed by GC-MS and classified by five organic impurities, and then sorted into four groups, which are Nagai type, Emde Type, Undetermined I type, and Undetermined II type.
The Journal of steroid biochemistry and molecular biology, 2014
Cannabis, or marijuana, the most commonly used illicit drug in the world, has been shown to be re... more Cannabis, or marijuana, the most commonly used illicit drug in the world, has been shown to be responsible for suppressing the production and secretion of androgens, particularly testosterone. However, despite such findings in animals, the chronic effects of marijuana use on human endocrine systems have proved to be inconsistent. Here, we investigated the reference ranges of urinary levels of testosterone (T) and epitestosterone (E) as well as their metabolic ratio of T/E in a Korean male population (n=337), which would enable an evaluation of abnormal changes in steroid metabolism induced by habitually administered cannabis. The T/E ratio was significantly decreased in the marijuana group (n=18), while the urinary testosterone concentrations were also tended to decrease. This study is the first to provide data for the reference values of two urinary androgens and T/E values among control Korean males, and, furthermore, suggests that the T/E ratio, though not testosterone levels, mi...
Lithiated NiO cathode dissolution has been a major problem for the development of molten carbonat... more Lithiated NiO cathode dissolution has been a major problem for the development of molten carbonate fuel cells (MCFCs). Many studies have been contributed to find new alternative cathodes; here, lithium cobalt oxide, LiCoO 2, was coated onto the commonly used NiO ...
Impurity profiling and classification of seized methamphetamine may play an important role in the... more Impurity profiling and classification of seized methamphetamine may play an important role in the interpretation of analytical results, the determination of the synthetic method employed, and the criminal investigations of drug traffic routes. Our study is focused on classifying seized methamphetamine samples according to the groups sorted by the types and quantities of impurities present in illicit methamphetamine samples. The samples (100mg) were dissolved in 2 mL of potassium phosphate buffer (pH 7.0), extracted with 200 microL of ethyl acetate under basic condition, and then analyzed by gas chromatography-mass spectrometry (GC-MS) with a DB-1 capillary column (30 m x 0.25 mm i.d., 0.25 microm). Five impurities are used as criteria for the classification of seized methamphetamine samples by Emde and Nagai method. A total of fifty-two samples of seized methamphetamine were analyzed by GC-MS and classified by five organic impurities, and then sorted into four groups, which are Nagai type, Emde Type, Undetermined I type, and Undetermined II type.
Recently, &am... more Recently, 'detox' agents have been popularly used as forms of diets or nutritional supplements. Especially, several cases have been reported that these detox agents have been used to mask drug tests among drug abusers. In the present study, capsule and drink types of detox agents were evaluated for their ability to alter the elimination of methamphetamine (MA) in rats. For this study, MA and its major metabolite, amphetamine (AP) in urine samples were determined using LC-tandem mass spectrometry after administration of the detox agents to MA-treated rats. As a result, significant differences were not shown between control and detox-dosed groups in the amounts of MA and AP excreted into urine as well as the volume of excreted urine. This result suggests that the detox agents tested may not affect the metabolism or elimination of MA and further might have minimal effect on narcotics detection in the urine samples of drug abusers.
... References 1. A. Shankar, R. Klein, BEK Klein, and SE Moss, Exp. Clin. Endocrinol. ... 20. AK... more ... References 1. A. Shankar, R. Klein, BEK Klein, and SE Moss, Exp. Clin. Endocrinol. ... 20. AK Hewavitharana and HL Bruce, J. Chromatogr., B, 2003, 784, 275. 21. SK George, MT Dipu, UR Mehra, P. Singh, AK Verma, and JS Ramgaokar, J. Chromatogr., B, 2006, 832, 134. 22. ...
Impurity profiling and classification of seized methamphetamine may play an important role in the... more Impurity profiling and classification of seized methamphetamine may play an important role in the interpretation of analytical results, the determination of the synthetic method employed, and the criminal investigations of drug traffic routes. Our study is focused on classifying seized methamphetamine samples according to the groups sorted by the types and quantities of impurities present in illicit methamphetamine samples. The samples (100mg) were dissolved in 2 mL of potassium phosphate buffer (pH 7.0), extracted with 200 microL of ethyl acetate under basic condition, and then analyzed by gas chromatography-mass spectrometry (GC-MS) with a DB-1 capillary column (30 m x 0.25 mm i.d., 0.25 microm). Five impurities are used as criteria for the classification of seized methamphetamine samples by Emde and Nagai method. A total of fifty-two samples of seized methamphetamine were analyzed by GC-MS and classified by five organic impurities, and then sorted into four groups, which are Nagai type, Emde Type, Undetermined I type, and Undetermined II type.
The Journal of steroid biochemistry and molecular biology, 2014
Cannabis, or marijuana, the most commonly used illicit drug in the world, has been shown to be re... more Cannabis, or marijuana, the most commonly used illicit drug in the world, has been shown to be responsible for suppressing the production and secretion of androgens, particularly testosterone. However, despite such findings in animals, the chronic effects of marijuana use on human endocrine systems have proved to be inconsistent. Here, we investigated the reference ranges of urinary levels of testosterone (T) and epitestosterone (E) as well as their metabolic ratio of T/E in a Korean male population (n=337), which would enable an evaluation of abnormal changes in steroid metabolism induced by habitually administered cannabis. The T/E ratio was significantly decreased in the marijuana group (n=18), while the urinary testosterone concentrations were also tended to decrease. This study is the first to provide data for the reference values of two urinary androgens and T/E values among control Korean males, and, furthermore, suggests that the T/E ratio, though not testosterone levels, mi...
Lithiated NiO cathode dissolution has been a major problem for the development of molten carbonat... more Lithiated NiO cathode dissolution has been a major problem for the development of molten carbonate fuel cells (MCFCs). Many studies have been contributed to find new alternative cathodes; here, lithium cobalt oxide, LiCoO 2, was coated onto the commonly used NiO ...
Impurity profiling and classification of seized methamphetamine may play an important role in the... more Impurity profiling and classification of seized methamphetamine may play an important role in the interpretation of analytical results, the determination of the synthetic method employed, and the criminal investigations of drug traffic routes. Our study is focused on classifying seized methamphetamine samples according to the groups sorted by the types and quantities of impurities present in illicit methamphetamine samples. The samples (100mg) were dissolved in 2 mL of potassium phosphate buffer (pH 7.0), extracted with 200 microL of ethyl acetate under basic condition, and then analyzed by gas chromatography-mass spectrometry (GC-MS) with a DB-1 capillary column (30 m x 0.25 mm i.d., 0.25 microm). Five impurities are used as criteria for the classification of seized methamphetamine samples by Emde and Nagai method. A total of fifty-two samples of seized methamphetamine were analyzed by GC-MS and classified by five organic impurities, and then sorted into four groups, which are Nagai type, Emde Type, Undetermined I type, and Undetermined II type.
Recently, &am... more Recently, 'detox' agents have been popularly used as forms of diets or nutritional supplements. Especially, several cases have been reported that these detox agents have been used to mask drug tests among drug abusers. In the present study, capsule and drink types of detox agents were evaluated for their ability to alter the elimination of methamphetamine (MA) in rats. For this study, MA and its major metabolite, amphetamine (AP) in urine samples were determined using LC-tandem mass spectrometry after administration of the detox agents to MA-treated rats. As a result, significant differences were not shown between control and detox-dosed groups in the amounts of MA and AP excreted into urine as well as the volume of excreted urine. This result suggests that the detox agents tested may not affect the metabolism or elimination of MA and further might have minimal effect on narcotics detection in the urine samples of drug abusers.
... References 1. A. Shankar, R. Klein, BEK Klein, and SE Moss, Exp. Clin. Endocrinol. ... 20. AK... more ... References 1. A. Shankar, R. Klein, BEK Klein, and SE Moss, Exp. Clin. Endocrinol. ... 20. AK Hewavitharana and HL Bruce, J. Chromatogr., B, 2003, 784, 275. 21. SK George, MT Dipu, UR Mehra, P. Singh, AK Verma, and JS Ramgaokar, J. Chromatogr., B, 2006, 832, 134. 22. ...
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