Methamphetamine values

Fig. 3 Concentrations reported for amphetamine-like compounds in surface water of different European and American countries. AM amphetamine MDA 3,4-methylenedioxy amphetamine MDMA 3,4-methylenedioxy methamphetamine (ecstasy) MA methamphetamine N/A Values not availabe, not measured...

Thus, comparison of the charge distribution calculated by CNDO/2, the pKa values and the partition coefficients shows that both NM-X and NM-N are excellent models for a study of conformation-activity relationships of methamphetamine. 

Stephenson GW, Williamson D, Base strengths of cyanoamines, /ACS, 80,5943-5947 (1958). Cited in Perrin Bases. No. 2937 ref. S75. NB Study used a glass electrode with liquid junction potential. Careful calibration of the pH meter was reported and activity effects taken into account. Also reported a pJCa value for methamphetamine, N-(2-cyano)ethyl = 6.95. The mean difference in pJCa caused by the presence of the 2-cyanoediyl group was about —3.28 log unit. 

The categorization of marijuana as a Schedule I drug is certainly controversial. No reputable expert in the field believes that marijuana is more dangerous than cocaine or methamphetamine. The abuse potential of barbiturate (a Schedule IV drug) is far greater than marijuana. A contentious issue is whether marijuana has any medically useful value. This will be discussed in detail in the next chapter. 

In 2003, the worldwide retail market value of marijuana products was 142 billion, cocaine was 71 billion, opiates (primarily heroin) was 65 billion, and methamphetamine, amphetamine, and ecstasy combined was 44 billion. While the U.N. report does not give a breakdown of expenditures for illegal drugs by country, there are estimates by continent. North America spent 144 billion (retail) or 44 percent of the world s total on illegal drugs. North Americas share of cocaine expenditures was 62 percent opiates, 14 percent marijuana, 55 percent and methamphetamine, amphetamine, and ecstasy, 57 percent. Therefore, more than half of the world s retail expenditures on cocaine, marijuana, and stimulant drugs comes from North America. 

Figure 16.9a shows the TLC/EASI-MS results for the spot corresponding to tablet 1 (Tl), which was positive for MDMA (m/z 194 and m/z 423 [24]) and thus confirms that MDMA and methamphetamine exhibited the same Rf in this solvent system (see Figure 16.7c). These results highlight the importance of coupling TLC and EASI-MS for a fast and conclusive analysis. Similar results were obtained for all other tablets (T2-T5 and T7-T8), except for T6, which showed an Rf value that was similar to those of caffeine and ketamine.

The most abundant ion peak in many compounds in the methamphetamine family is found at 58 amu. Mass spectra are processed by assigning the largest peak (called the base peak) a value of 100 and scaling all other peaks to that value. Consequently, many minor peaks may be all but lost. Removing the base peak and renormalizing the... 

On the Stand (Legal Issues and Questions) In methamphetamine and similar cases in which diluted samples are encountered, the forensic chemist may be asked about "usable quantity." In some jurisdictions, the prosecution is required to prove not only that the defendant had a controlled substance, but that the amount possessed was usable. This concept is abo referred to as "measurable quantity." Since quantitation of the methamphetamine femily b not routinely performed, a concentration or percentage value of purity b not always available. The defense may argue that the amoimt present was so small as to be negligible or harmless. Because exhibits are received with low concaitrations of the controlled substance, this b a reasonable question. 

Pseudoephedrine (a similar in stmcture to methamphetamine and MDMA) was detected in the Virgin River (a tributary of the Colorado River) at Cedar Pocket, AZ. Cedar Pocket is located along the digin River and is approximately 18 km downstream from the St. George, UT, WWTP, which empties into the Virgin River. One possibility for detection at this site is the negative log Dow = -1.85, at pH 7, as calculated for pseudoephedrine. This negative value indicates that this compoimd is more hydrophilic, and, therefore, more likely to stay in the water column, as compared to methamphetamine and MDMA. 

For forensic analysis, target metabolomics is focused on the quantitative and qualitative analysis of specific metabolites such as drugs in blood, urine, tissue, or hair. In a recent study using IM-MS, metabolites in hair samples were analyzed. Four of the nine hair samples were positive for caffeine and nicotine and one sample tested positive for methamphetamine in the mass spectrum. However, when mobility data was considered the caffeine and nicotine were found to be true positives while the methamphetamine was determined to be a false positive. The mobility values for the unknown with the mass of methamphetamine did not match that of the methamphetamine standard. This is an excellent example of utility of isomeric/isobaric separation in mobility space. 

Estimate the pK, values for cocaine, amphetamine, and methamphetamine hydrochlorides. Why are the salts more commonly used for oral administration and the free bases for inhalation ... 

Cocaine is a tertiary amine, methamphetamine a secondary amine, and amphetamine a primary amine. Typical pK values for [RjNHjT [RjNHj], and [RNH3] are, respectively, 9.76, 10.66, and 10.63. The salts are water soluble and hence more easily ingested, but they are nonvolatile, so difficult to inhale. The free bases are less water soluble but relatively volatile, hence easier to inhale. Since the lungs are richly supplied with blood vessels, inhalation results in higher and faster bioavailability of the drugs. 

The following chiral reagents were employed for diastereomer formation before sample application and chromatography on silica gel or silica gel G TLC plates (L)-leucine Af-carboxyanhydride for D,L-dopa-carboxyl- " C separated with ethyl acetate/formic acid/water (60 5 35) mobile phase and detected by ninhydrin [7 f 0.38 (d)/0.56 (l)] [43] Af-trifluoroacetyl-L-prolyl chloride for D,L-amphetamine separated with chloroform/methanol (197 3) and detected by sulfuric acid/formaldehyde (10 1) (Rf 0.49 (d)/0.55 (l)) [44] Af-benzyloxycarbonyl-L-prolyl chloride for D,L-methamphetamine separated with n-hexane/ethyl acetate/acetonitrile/diisopropyl ether (2 2 2 1) and detected by sulfuric acid/formaldehyde (10 1) [/ f 0.57 (l)/0.61 (d)] [44] (l/ ,2/ )-(-)-l-(4-nitrophenyl)-2-amino-1,3-propanediol (levobase) and its enantiomer dextrobase for chiral carboxylic acids separated with chloroform/ethanol/acetic acid (9 1 0.5) and detected under UV (254 nm) light R[ values 0.63 and 0.53 for 5- and / -naproxen, respectively) [45] (5)-(4-)-a-methoxyphenylacetic acid for R,S-ethyl-4-(dimethylamino)-3-hydroxybutanoate (carnitine precursor) with diethyl ether mobile phase [/ f 0.55 R)/0J9 (5)] [46] and (5)-(4-)-benoxaprofen chloride with toluene/acetone (100 10, ammonia atmosphere) mobile phase and fluorescence visualization (Zeiss KM 3 densitometer 313 nm excitation, 365 nm emission) (respective R values of R- and 5-isomers of metoprolol, oxprenolol, and propranolol were 0.24/0.28, 0.32/0.38, and 0.32/0.39) [47]. 

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