MCA

An alternative to the TAC and PHA/ADC is the time-to-digital eonverter (TDC), a unit that eombines the fiinetions of the TAC and PHA/ADC. There are start and stop inputs and an output that provides a binary number direetly proportional to the time diflferenee between the stop and start signals. The TAC ean be direetly eonneeted to a MCA or PC with the appropriate digital interfaee. 

Figure Bl.10.7. Electron impact ionization coincidence experiment. The experiment consists of a source of incident electrons, a target gas sample and two electron detectors, one for the scattered electron, the other for the ejected electron. The detectors are coimected tlirough preamplifiers to the inputs (start and stop) of a time-to-amplitiide converter (TAC). The output of the TAC goes to a pulse-height-analyser (PHA) and then to a nuiltichaimel analyser (MCA) or computer.

Caustic soda is classified as a corrosive material by the DOT and DOT regulations and specifications must be followed for handling, labeling, and transportation in containers. Warning labels are recommended for containers of caustic soda solutions and anhydrous caustic soda by the MCA (79). The DOT identification number is UN1824 for 50 or 73% Hquid, and UN1823 for anhydrous caustic. 

MCA Chemical Manufacturers Association (was Manufacturing Chemists NIOSH... 

Product Bulletin, P-492, FMC Lithium Division, Gastonia, N.C. Technical Data Bulletin, 107A, Cypms-Foote Mineral Co., Kings Mountain, N.C. Chemical Safety Data Sheet SD-91, MCA, Washington, D.C., 1966. 

Chemistry and Biology," MCA Professional Reference Book, American Chemical Society, Washington, D.C., 1995. 

K. P. Beardsley, "An Introduction to the Physics of Material Science," at the MCA Meeting of the 147th Rubber Division, Philadelphia, Pa., May 2—5,1995, American Chemical Society, Washington, D.C. 

L. D. Albia and M. M. Lynn, Chemistry of Elastomers Containing Vinylidene Fluoride, at the MCA Meeting of the Energy Rubber Group, Rubber Division, Educational Symposium, Arlington, Tex, Sept. 23, 1985, American Chemical Society, Washiagton, D.C. 

J. R. Dunn and G. C. Blackshaw, NBR—Chemistry andMarkets, at the MCA Energy Rubber Group Educational Symposium, Dallas, Tex, Sept. 24, 1985, American Chemical Society, Washington, D.C. 

Tables 16 and 17 Hst tke analytical test methods for different properties of interest. The Manufacturing Chemists Association, Inc. (MCA) has pubUshed the Chemical Safety Data Sheet SD 63, which describes in detail procedures for safe handling of use of toluene (46). The Interstate Commerce Commission classifies toluene as a flammable Hquid. Accordingly, it must be packaged in authorized containers, and shipping must comply with ICC regulations. Properties related to safe handling are autoignition temperature, 536°C explosive limits, 1.27—7.0 vol % in air and flash point 4.4°C, closed cup.

Appllca.tlons. MCA is used for the resolution of many classes of chiral dmgs. Polar compounds such as amines, amides, imides, esters, and ketones can be resolved (34). A phenyl or a cycloalkyl group near the chiral center seems to improve chiral selectivity. Nonpolar racemates have also been resolved, but charged or dissociating compounds are not retained on MCA. Mobile phases used with MCA columns include ethanol and methanol. 

Generally, monochloroacetic acid [79-11-8] (MCA) is added to the reaction slurry containing sufficient excess sodium hydroxide to neutralize the MCA and effect its reaction. The use of esters of MCA has also been reported (52). Common reaction diluents are isopropyl alcohol, /-butyl alcohol, or ethyl alcohol (53,54). Dimethoxyethane has also been reported to be effective (55). The product is isolated and washed with aqueous alcohol or acetone to remove by-product salts. Unpurified cmde grades are generally prepared in the absence of diluents (56—59). 

Manufacture. Purified hydroxyethylcellulose is manufactured in diluent-mediated processes similar to those used to produce carboxymethylceUulose except ethylene oxide [75-21-8] is used in place of MCA (63,64) ... 

S. Newman, "Use of Butyl Elastomers ia the Medical Industry," presented at MCA Rjcbber Division Meeting, Las Vegas, Nev., May 29, 1990. 

Manonen, T. B., Bell, K. A., Phalen, R. F., Wilson, A. I-., and Ho, A. (1982). Growth rate mca snrements and depo.sition modelling of hygroscopic aero.sols in human tracheobronchial models. Ann. Occup. Myg. 26, 93-108. 

ANSI. FM, IEEE, lES, NEMA, NFPA, NSC,UL,USCG AMCA, ANSI, ASME, NFPA MCA, NFPA, NSC, OSHA AIA, ANSI, ASTM, AWWA, CGA, CMA, Cl, CTI, FM, HMRB, ISA, NBS, NFPA, NSC, OIA. TEMA, UL, USCG AGA, AICliE. AIUA, AMCA, ANSI, API, ARI, ASHRAE, ASTM, EPA, ISA, NFPA, NSC, OSHA, UL... 

---