The wide use of Dipyrone as a drug individually or in mixtures presupposes the rapid development and improvement of new methods.
ACKNOWLEDGMENT The authors are greatly indebted to Al. Alexandrov from the “Paisii Hilendarskii” University in Plovdiv, Bulgaria, for his valuable assistance in preparing the present work.
(3) A. M. Chodakowski and T. Mosiniak, Acta Pol. Pharm., 24 (5), 511
(1967). (4) K. Kato, M. Urneda. and S. Tsubota, Yakuzaigaku, 24, 116 (1964); Chem. Abstr., 61,15936h. (5)2.Koltchev and I. Benchev. Farmatsiya, 10 (l),1 1 (1960). (6)E. Maggiorelli and Z. Conti, Farmaco, 15, 179 (1960). (7)A. Vegh, Gy.Szasz, and P. Kertesz, Pharmazie, 16,512 (1961). (8)Naobumi Oi, Vakugaku Zassbi, 85 (Il),1001 (1965);Chem. Abstr.. 64,
4870f.
LITERATURE CITED (1)P. S.Vassileva-Alexandrova, Mikrochim. Acta, 4, 615 (1971). (2)V. Koen, Farmatsiya, 5, 23 (1955).
RECEIVEDfor review August 27, 1974. Accepted February 18, 1975.
Determination of Carbonaceous Material in Sediments by Reductive Pyrolysis and Spectrophotometry Neil R. McQuaker and Tony Fung Chemistry Laboratory, Water Resources Service, 3650 Wesbrook Crescent, Vancouver B.C. V6S 2L2, Canada
Recently, various workers have been concerned with the determination of carbonaceous matter in bottom sediments of lakes and rivers (1-6). Particular attention has been focused on the chemical characterization of the organic fraction since the organic loading of sediments and the associated increase in biological activity is likely to affect water quality by causing a depletion of available oxygen together with increased nutrient levels in the overlying water (2, 5 ) . T h e chemical characterization of the organic fraction of the carbonaceous matter in sediments has included analysis for both organic carbon (1-3) and carbohydrates (5,6). Various techniques have been used for the determination of organic (and total) carbon in sediments (and soils). These include both wet and dry combustion methods which depend on the quantitative conversion of the organic (or total) carbon to C02 (7-9). In addition, an approximate assay technique reported by Bremner and Jenkinson has been used (IO). Since Bremner and Jenkinson’s method is equivalent to the determination of chemical oxygen demand (COD) in wastewaters it has been called the COD method (2). With the exception of instrumental dry combustion methods ( 9 ) , the techniques referred to above for the analysis of organic (and total) carbon in sediments (and soils) are time consuming (e.g., 2-3 hr). This contrasts with techniques for water samples which require no more than 5 min. An instrumental technique described by Van Hall and Stenger (1I ) makes use of a nondispersive infrared detector and measures the C02 resulting from the combustion of the carbonaceous compounds. Total and inorganic carbon can be differentiated by the use of different combustion columns and temperatures. More recently, an instrumental technique has been described by Takahashi et al. ( 1 2 ) which makes use of a flame ionization detector and measures the CH4 resulting from the catalytic reduction of both volatile organic compounds (VOC) and COz; the VOC and COZ are produced as the result of vaporization (90 “C) and subsequent pyrolysis (850 “C) of the sample in the presence of a strong oxidant. Total and organic carbon may be differentiated by the use of a by-pass column for CO2 from inorganic carbonates. In both the infrared and flame ionization techniques,
sample handling simply involves the introduction of microliter quantities of the sample into the analytical train. Clearly, the adaptation of either technique to sediment samples could most readily be effected by using a homogeneous suspension of the sediment. In the reductive pyrolysis flame-ionization technique described by Takahashi et al. (12), a microliter pipet (with disposable polypropylene nonwetting tips) may be used to introduce the sample directly into the platinum boat containing the oxidant. This ensures that the sample, including any particulate matter, is in intimate contact with the oxidant from the outset of the analysis, This contrasts with the infrared technique described by Van Hall and Stenger ( I 1 ). In this case, a microliter syringe is used to introduce the sample into a stream of oxygen which then sweeps the sample into the combustion tube. The use of a microliter syringe (which can present problems when samples contain particulate matter) together with the use of an oxygen stream to carry the sample to the combustion tube makes it uncertain that all the particulate matter in the sample will come into (intimate) contact with the packing material of the combustion tube. I t is to be noted, though, that the combustion-infrared technique has been used for the analysis of raw wastewaters and diluted sludges (13). Schaffer e t al. ( 1 3 ) have used a blender to prepare suspensions of samples of this type. After the sample was homogenized, a microliter syringe was used to remove a 2O-kl aliquot from the blender. However, work done in this laboratory has shown that the method described by Schaffer et al. does not necessarily allow for the isolation of a representative portion of the sample in a 2 0 - 4 aliquot ( 1 4 ) .This was found to be particularly true if the sample contained large particles which settled rapidly, and it must be assumed that the precision data presented by Schaffer and coworkers are for samples which have particle sizes of about 20 p or less. Since most sediments are likely to contain a substantial sand fraction, only a small fraction of the particles in sediments are expected to have sizes of less than 20 b. Thus, for determinations involving suspensions of sediments the reductive pyrolysis-flame ionization technique apparently offers the most promising prospects. In the present work, we have explored the feasibility of ANALYTICALCHEMISTRY, VOL. 47, NO. 8, JULY 1975
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Table I. Precision and Accuracy for the Total Carbon and Carbohydrate Tests Sample No.
Analysis
Total carbon
Carbon added, m g / g a
A 15.52(G)
B 18.96(G) C 8.64(G)
D 8.22(C)
Carbon found, r n g / g b
Re1 std de”, %
21.33 f 0.71 35.86 0.81 21.28 0.83 39.95 0.87 10.84 i 0.93 18.87 + 1.23 13.48 0.71 21.80 + 1.02
3.3 2.5 3.9 2.2 8.5 6.5 5.2 4.7 4.6
* * * *
Mean Carbohydrate
Recovery, ?
