Tables. Prepare tables in a consistent form, furnish each with an appropriate title, and number consecutively using Roman numerals in the order of reference in the text. Type each table on a separate page, and collate at end of manuscript. Figures. Submit original drawings (or sharp glossy prints) of graphs and diagrams prepared on tracing cloth or plain paper. If structures are given in the text, original drawings should be provided. All lines, lettering, and numbering should be sharp and unbroken. If coordinate paper is used, use blue cross-hatch lines as no other color will “screen out”. Typed lettering does not reproduce well; use black India ink and a lettering set for all letters, numbers, and symbols. On 8- X 10-inch copy, which we prefer, lettering should be at least inch high and 0.017 inch thick-for example, with a Leroy lettering set, use template 120 C and pen No. 0. Symbols should be compatibly sized. Lettering on copy of other sizes should be in proportion. Label ordinates and abscissas of graphs along the axes and outside the graph proper. Supply glossy prints of photographs. Sharp contrasts are essential. Number all figures consecutively using Arabic numerals in the order of reference in the text. If drawings are mailed under separate cover, identify by name of author and title of manuscript. Figure Captions. Include, on one page, a list of captions and legends for all illustrations. Make the legend a part of the caption rather than inserting within the figure. Keep captions as brief as possible and include detailed information in the text. BRIEF. On a separate page, state in 30 words or less the significant results obtained emphasizing precision and accuracy data when
possible. Do not repeat the title. No Briefs are necessary for Correspondence or Aids. NOMENCLATURE. Nomenclature should conform with rules established by the International Union of Pure and Applied Chemistry, the Nomenclature Committee of the American Chemical Society, and the Chemical Abstracts Service. Avoid trivial names. Well-known symbols and formulas may be used (write out in title and abstract) if no amtiguity is likely. Define trade names and abbreviations at point of first use. First letter of trade names should be capitalized. Use consistent units of measurement (preferably metric) and give dimensions for all terms. If nomenclature is specialized, as in mathematical and engineering reports, include a Nomenclature section at end of paper, giving definitions and dimensions for all terms. Write out names of Greek letters and other special symbols in margin of manuscript at point of first use. Write all equations and formulas clearly (type if possible) and number all equations in consecutive order. Place superscripts and subscripts accurately: indicate capital letters and distinguish between characters which are alike on the keyboard-e.g., one and the letter “EL,” zero and the letter “OH.” Avoid superscripts which may be confused with exponents. For numbers less than one, zeroes precede the decimal point. For specialized nomenclature used by this journal, see “Spectrometry Nomenclature” and “Guide for Use of Terms in Reporting Data in ANALYTICAL CHEMISTRY” which appear annually at the end of the technical section in the December issue. From time to time, ANALYTICAL CHEMISTRY publishes special nomenclature guides promulgated by various organizations.
Spectrometry Nomenclature We have compiled the following list of terms, their definitions, and abbreviations, which occur most frequently in papers on spectrometry. The list indicates our preferred usages in an attempt to obtain some consistency in a field where much discrepancy exists.
Absorbance, A. (Not optical density, absorbancy, or extinction.) Logarithm to the base 10 of the reciprocal of the transmittance A = log10 (1ln.
Absorptivity, a. (Not k). (Not absorbancy index, specific extinction, or extinction coefficient.) Absorbance divided by the product of the concentration of the substance and the sample path length, A a =bc
Absorptivity, Molar, e. (Not molar absorbancy index, molar extinction coefficient, or molar absorption coefficient.) Product of the absorptivity, a, and the molecular weight of the substance. Angstrom, A. Unit of length equal to 1/6438.4696of wavelength of red line of Cd. For practical purposes, it is considered equal to lo-* cm. Beer’s Law. (Representing Beer-Lambert law.) Absorptivity of a substance is a constant with respect to changes in concentration. Concentration, c. Quantity of the substance contained in a unit quantity of sample. (In absorption spectrometry it is usually expressed in grams per liter.) Frequency. Number of cycles per unit time. Infrared. The region of the electromagnetic spectrum extending from approximately 0.78to 300 micrometers. Mlcrorneter, pm. Unit of length equal to cron.)
meter. (Do not use mi-
Nanometer, nm. Unit of length equal to limicron.)
meter. (Do not use mil-
Sample Path Length, b. (Not I or d.) Internal cell or sample length, usually given in centimeters.
Spectrograph. Instrument with an entrance slit and dispersing device that uses photography to obtain a record of spectral range. The radiant power passing through the optical system is integrated over time, and the quantity recorded is a function of radiant energy. Spectrometer, Optical. Instrument with an entrance slit, a dispersing device, and with one or more exit slits, with which measurements are made at selected wavelengths within the spectral range, or by scanning over the range. The quantity detected is a function of radiant power. Spectrometry. Branch of physical science treating the measurement of spectra. Spectrophotometer. Spectrometer with associated equipment, so that it furnishes the ratio, or a function of the ratio, of the radiant power of two beams as a function of spectral wavelength. These two beams may be separated in time, space, or both. Transmittance, T. (Not transmittancy or transmission.) The ratio of the radiant power transmitted by a sample to the radiant power incident on the sample. Ultraviolet. The region of the electromagnetic spectrum from approximately 10 to 380 nm. The term without further qualification usually refers to the region from 200 to 380 nm. Vlslble. Pertaining to radiant energy in the electromagnetic spectral range visible to the human eye (approximately 380 to 780 nm). Wavelength. (One word.) The distance, measured along the line of propagation, between two points that are in phase on adjacent waves-units A, wm, and nm. Wavenumber. (One word.) Number of waves per unit length. The usual unit of wavenumber is the reciprocal centimeter, cm-’. In terms of this unit, the wavenumber is the reciprocal of the wavelength when the latter is in centimeters in vacuo.
ANALYTICAL CHEMISTRY, VOL. 49, NO. 4, APRIL 1977
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