Classification of Analytical Samples PHILIP J . ELVWG Purdue University, Lafayette, Indiana
T
HE convenient classification and arrangement of sample are present they may be differentiated by use of the samples used in the various courses in quantita- a fourth digit, e. g., HlOOO to HI099 for ferric salts and tive analysis is a decided problem in many colleges HllOO to HI199 for ferrous salts, or 1000 for chlorides, and universities which possess large collections of ana- 1100 for nitrates, and 1200 for sulfates of the same lytical samples. In an attempt to systematize the metallic element. arrangement of samples for quantitative analysis and to The other sixteen classes of samples, J to 2, omitting facilitate the keeping of records of these samples the I and 0, provide for the numbering not only of the alloy classification shown in Table 1was devised. The basis and rock samples used in the ordmary elementary of the system of classification is the sample number, courses in quantitative analytical chemistry but also consisting in general of a letter and a three-digit num- for the samples necessary for the usual courses in ber, e. g., 0 6 4 3 . The letter indicates the class to which metallurgical analysis, technical analysis of all types, the sample belongs, the first or hundredth digit shows rock analysis, food analysis, agricultural analysis, the subclass or type of the sample and the last two digits quantitative organic analysis, spectroscopy, etc. Progive the number of the particular sample of the given vision is also made for primary standards and various type. The vertical column on the left of Table 1 gives other special classes of substances. Ample provision is the code letters indicating the classes of samples while allowed for new samples and classes of samples. The the other vertical columns provide for ten types of classes or samples may be readily extended by using a samples in each class. The arrangement, in part, is double key letter, i. e., AA, A B , etc. based on the Periodic System. In most cases there would be no real need to change The first eight classes of samples, A to H , provide the present numbers on samples in switching over to for simple unknowns of the elements of the eight groups this or a similar classification of samples. It would be of the Periodic System, the elements in each group being merely necessary to prefix a key letter and a key number indicated by the hundredth digit used. Thus, samples to the present two- or three-digit number, aluminum B300 to 23399 are intended for the determination of salt sample No. 12 becoming C212. Where students calcium. Numbers 1 to 99 in each class are reserved may see into the sample storeroom the advantage of a for samples containing more than one member of the sample being marked "C212" instead of "Aluminum 12" group, e. g., A 1 to A99 might be samples in which both is evident. sodium and potassium are to be determined. Numbers Arrangement of the samples alphabetically and 100 to 599 are, in general, reserved for the elements of numerically in the storeroom greatly facilitates locating the principal subgroup, numbers 600 to 899 for elements a sample of a given type and number, especially when a of the other subgroup. Numbers 900 to 999 are re- large number of samples containing only a few of each served for samples in which the elements of the group type are kept in the same location. Record-keeping is are present or are to be determined as anions, e. g., GMO simplified since the sample records can be systematized to G699 would be samples of manganous salts while on the same alphabetical-numerical basis. G9OO to G999 could be samples for the determination of TABLE 2 permanganate. Similarly, F200 to F299 could be samples for the determination of sulfide and F900 to Key Lclln TyPc of Sample A Element F999 for the determination of sulfate. Usually, the B Simple binary d t or oxide samples in classes A to H will consist of simple salts Simple salts, r . g., metallie rulfates C Simple mes. C. g., metallic oxides or sulfides D diluted with inert material. E Complex ores, e, 8.. phosphate rock If more than a hundred samples of a piven species are P
B2999 if necessary. If several types of the same
XO~.:
~h~
rsmp~ermay be diluted ~ 5 t h
inert
An alternative system of classification of analytical ment in the group and the particular sample as in the samples is also based in part on the Periodic System, scheme of classification previously described. Thus, employing for the first eight classes of samples a two- AF6OO to AF699 would be copper-base alloys while letter, three-digit code, e. g., BD372, where the first let- EG306 might be a sample of Paris Green in which only ter, A to H, denotes the group of the Periodic System arsenic is to be determined. For classifying steels, while the second letter indicates the nature of the sam- fuels, agricultural products, etc., the original system is ple as shown in Table 2. The number locates the ele- applicable. TABLE 1 CLASSIX-ICATION OP ANA'YTICALSAMPLBS
sorn*ic Numbers
HCOI
1-99
100-199
+ COa
Li Be B C N 0
Mixed halides
F
Bureau of Standard3 samples
K L
Iron
Steel, containing Cu
Steel, containing W and Cr Cu ores
Steel, containing W, Cr, and V Zn ores
Steel. containing Mo
Sted, containing Mo. W. Cr. V
Al oren
Pb ores
"Silicates" "Limeatones" Coal and coke Fertilizen
Feldspars Limestones Petroleum cruder Feed ntu6s
Orthoelases Dolomitie limestones Gasoline Insecticides
Dolomites Light burning oils Soils
N P
Q
Alloy steels
R
Ores, mctallL content ores, non-metallic content Silicata Carbonate.. etc. Fuels Agricultural and food pmducte
T
U V
W X
Y
Z
ampler
Bronze Zn-base alloyn Sb-base alloy^ Co-base alloys Steel, contaioing Ni
Brand bronze Bebare alloys Sn-base alloys Ni-base alloys
S
Fe Bureau of Standards
Na ME A1 Si P S CI Co Staodaqds for rpeefroreopy
Brass Mg-ba3e dloys P b ~ b a r ealloys Ni-Cr alloys Plain carbon steel
Copper alloy' Light metal alloys "White metal" alloys Resistant alloys Iron and s t 4
M
200-299
Mkcellaneous teehnieal products Bl-hing powders Paints Carbon-hydrogen Samples for organic quantitative Metals and residues analysis Gare.. waters, etc. Single or "pure,' gases Flue gases
cr Ba TI Pb Bi Po and U
Fuel gases
Rh Primary standards, alkalimetry
Cr Mn Pd primary standards. oridimetry
C u ~ Nalloys i At-base alloys Solders
Cu-Ni-Zn alloys
Cu-Mn alloys
Cu-Si alloys
Babbitts
Fusible alloys
Pyrophoric alloys
Steel. containing Si, Mn Steel containing Mo
Steel, containing c r or
Steel, containing Cr and Ni
Steel, containing Cr and V
Mn ores
Ni
Glass Boiler scale
Siliea refractories Soda nrh
Greaser Meat products
waxer
Ru primary sfaod*rdr, midimetry
and
v
Miscellaneous g a ~ c s
AS Cd Ce z r and Hf Cb Mo Ma 0s primary ~t%"dard*, reduetimefry
V
Textiles Halogen
%rrplosives Nitrogen
cu Zo
Sc and Y Ti
Al-, phosphor-, nod other bmnres Cd-base alloys Bi-base alloys
Rare earths Th Ta
w
BIOJ and borate CO.
so.
Re
Ir
Pf
primary standards, precipitimetry and complex formation
Ag, A", and P t alloys Sfeel, containing "X" Ferro-alloys
Steel, containing "X.'nnd "Y'. Alloying metals
"X" Sulfide ores cements Burned limestone. lime. magnesia, etc. Fuel and road oils Dairy products
ore5
direct"
Rubber, paper, ete.
Carbohydrates and starcher organic chemical.
Sulfur
Molceulsr weight
Neutralization equivalent Functional group*
Potable wate,
Boiler feed water
Sewage and effluents
Miscellaneous waters
Bitvminovs pmduet3 Oils and fats
Beverages
Metallic oaltr
Non-metallic chemical.
"Moisture determination"
specific gravity, density
