A Modified Phenylfluorone Method for Determining Organotin Compounds in the ppb and Subppb Range All reagents used were of the highest available purity and no pretreatment was required. Sodium Hydroxide (50%). 50 g of NaOH pellets were dissolved in distilled water and diluted to 100 mL after cooling. OTC Stock Solution. 44.5 mg of bis(trinbutyltin) oxide (TBTO) (MT Chemical Co., Rahway, NJ (C.A. registry number 56359) Assay (9) 98.9%) was dissolved in 95% ethanol, quantitatively transferred to a 500 mL volumetric flask and diluted to volume in the same solvent to yield 35.5 ~g of tin per mL. TBTO Standard Solution. 3.0 mL of OTC stock solution was diluted to 100 mL with 95% ethanol to prepare a 1.068 ~gmL tin solution. This standard was prepared fresh as needed. Phenylfluorone. I0 mg of phenylflluorone (Eastman Kodak Co., Rochester, NY) 2,6,7trihydroxy9phenylisoxanthane3 one, was dissolved in 25 mL of ethanol containing 0.2 mL of concentrated sulfuric acid, and dilute to 100 mL with ethanol. This solution is stored in the dark and further diluted to a 10 4 M solution when used.
Trang 1A Modified Phenylfluorone Method for Determining
Organotin Compounds in the ppb and Sub-ppb Range L.R Sherman* and T.L Carlson
Department of Chemistry, The University of Akron, Akron, OH 44325
This research was supported by Edna McConnel Clark Founda-
tion, New York, NY
*Author to whom correspondence should be sent
Methods and Materials
Reagents
Introduction
Yrialkyl organotin compounds (OTC) are used as biocidal
agents in controlled-release antifouling preparations (1), mol-
luscicides (2) and mosquito larvicides (3) In order to determine
organotin emission rates from dispensing pellets, and monitor
residual toxicant levels in the hydrosphere, absorbing solid
and biological specimens, it is imperative that analytical
methods be developed that will accurately assess ultra-low con-
centrations T h e method must be specific for organotin species
and overcome interference from the ubiquitous inorganic tin
background
The phenylfluorone method has been proven to be a superior
analytical method having sensitivity in the tzg range when the
colored material is subjected to chloroform extraction (4) The
use o f sensitizers, cetyltrimethylammonium bromide (CTAB),
and cetylpyridinium bromide (CPB), enhances tin IV -catechol
violet complex color formation, but gives a bathocromic shift
(5,6,7) The use of C T A B with phenylfluorone at pH 1.2 yields
an intense k,,o~ at 530 nm and has been successfully utilized in
the range of 0.1 to 4 ppm tin (8) The technique reported herein
is a modification of the latter method keyed to the specific de-
termination of O T C in the sub part-per-billion range
All reagents used were of the highest available purity and
no pretreatment was required
Sodium Hydroxide (50%) 50 g of N a O H pellets were dis- solved in distilled water and diluted to 100 mL after cooling
OTC Stock Solution 44.5 mg of bis(tri-n-butyltin) oxide (TBTO) ( M & T Chemical Co., Rahway, NJ (C.A registry number 56-35-9) Assay (9) 98.9%) was dissolved in 95% ethanol, quantitatively transferred to a 500 mL volumetric flask and diluted to volume in the same solvent to yield 35.5 /~g of tin per mL
TBTO Standard Solution 3.0 mL of O T C stock solution was diluted to 100 mL with 95% ethanol to prepare a 1.068
~ g / m L tin solution This standard was prepared fresh as needed
Phenylfluorone I0 mg of phenylflluorone (Eastman Kodak Co., Rochester, NY) 2,6,7-tri-hydroxy-9-phenylisoxanthane-3- one, was dissolved in 25 mL of ethanol containing 0.2 m L of concentrated sulfuric acid, and dilute to 100 mL with ethanol This solution is stored in the dark and further diluted to a 10 -4
M solution when used
CTAB 0.10 g of cetyltrimethylammonium bromide (East- man Kodak Co., Rochester, NY) was dissolved in warm dis- tilled water and diluted to 100 mL; 1.0 mL was further diluted to
25 mL when used
Preparation of Calibration Curve
Standard T B T O solution, 0-4.0 ug (0,1,2,3, & 4 mL), was added to 200 mL of distilled water and extracted with two 20
mL aliquots of hexane Extracts were then added to 1 mL of cone H2SO4 in a 30 mL beaker and the hexane slowly evapo- rated under reflux conditions When HzSO4 reflux initiated, 30% hydrogen peroxide was added one drop at a time to the sample to destroy the organic material and oxidize the tin Heating continued until the colorless refluxing acid filled ap- proximately 2/3 of the beaker About 15 mL of distilled water and 2.2 mL of C T A B were added to the cooled samples, 50%
N a O H was used to adjust pH to 1.2, and materials were quanti- tatively transferred to 25 mL flasks 1 mL of phenylfluorone and distilled water, previously adjusted to pH 1.2 with H2SO4, was added to dilute the samples to volume After 40 minutes at
31
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Trang 2room temperature, the samples were measured on a Bechman
25 U.V.-Vis spectrophotometer at the ,X.m~ near 535 nm using
water as the blank
Fleld Samples
A number of controlled release monolithic molluscides con-
taining T B T O have been field tested on St Lucia Island in the
Caribbean Environmental samples of water, soil, plants, fish,
and other aquatic life have been collected and have been qual-
itatively tested for O T C as follows:
Water Samples: 200 mL of water was extracted with hexane
as described above for the TBTO curve
Solid Samples: The soils were extracted with hexane and the
hexane removed as described above 2 mL of H2SO4 was used
Plants, Fish, and Other Aquatic' Specimens: These were
totally dissolved in 2-4 mL sulfuric acid and analyzed as de-
scribed previously
Results
Extractions
A set of standard T B T O samples were prepared as outlined
in the experimental section under T B T O Standards and were
extracted with 1,2,3, and 4 -10 mL samples of hexane and de-
termined as described under Preparation of Calibration Curve
The results, given in Table I, indicate that two bexane extrac-
tions will quantitatively remove T B T O from an aqueous sam-
ple The results for all the samples were within the experimental
limitations of the method; however, because the single extrac-
tion was less than quantitative, a second extraction is recom-
mended to avoid errors
Addition of Inorganic Tin
To each of five standard T B T O samples was added 3.156 #g
of inorganic tin The samples were extracted and processed as
field samples The results are tabulated in Table 11 Although
the percent of recovered tin varied randomly from one sample
to the next, the average for the two sets of samples indicates
that inorganic tin is not extracted with the organotin and that
there is negligible suppression or enhancement of the color
development
The Slope of the Lines
The slope of the line, calculated by the method of least
squares, for the inorganic tin standards was 0.0346 and the
intercept was 0.0144 The slope of the T B T O curve was 0.0344,
and intercept was 0.0580 with an average correlation coefficient
of 0.975 Three different technicians have been using this
method; their first sample usually produced a slope of tess than
0.030 and a correlation coefficient of approximately 0.94 As
their technique improved, the slope was enhanced After three
or four attempts, the correlation coefficient was better than 0.99
with a standard deviation of 0.0133 or less The slope o f t h e O T C
and inorganic tin is definitely within experimental values; how-
ever, when corrected for the different procedure they are about
20% greater than the published values(8) and reflect an improve-
ment in the analytical method The large difference in the inter-
Table I Effect of Hexane Extraction Upon the Analysis of T B T O
Sample ppb Sn Analysis % Recovered
1 Extraction 21.6 20.5 94.9
2 Extraction 21.6 21.6 100.0
3 Extraction 21.6 22.3 103.2
4 Extraction 21.6 21.6 100.0
Table II Effect of Inorganic Tin Upon Analysis of TBTO
Micrograms*
Sn as TB TO Micrograms Added to Recovered % Recovered Samples 200 mL of H20 Set l Set2 Set1 Set2
0 0.00 0.00 0.00 0.00 0.00
1 1.08 0.94 1.05 87.0 97.2
2 2.16 2.03 2 3 1 94.0 108.9
3 3.24 3.26 2.77 100.8 85.5
4 4.32 5.10 4.29 118.0 99.3
Average 99.9 97.2
"Each sample contained 5.710,ug of tin sulfate
cepts is due to either colored impurities in the hexane, sulfuric acid and hydrogen peroxide, or due to the fact that different spectrophotometers and cells were used in preparing the two curves Furthermore, only unmatched 1 X 1 cmcells wereavail- able in preparing the O T C curve whereas matched 1 X 10 mm cells were available in preparing the inorganic curve
Field Samples
A large number of environmental samples (approximately 400) consisting of water, soil, plants, fish, and other aquatic life were recovered from the test area on St Lucia Island in the Caribbean and have been analyzed for residual OTC The en- vironmental samples were treated as described above and the organotin assayed as tin varies f r o m non-detectable to 44 ppb, which corresponds to 8.8 ~ug of tin Most of the samples con- tained between 250 and 1.00 ug of tin (10) Although the data
is readable to three significant figures, reproducibility of re- plicated environmental samples was about + I in the second significant figure
C o n c l u s i o n s
The modified phenylfluorone method for analyzing tin can
be used for the specific analysis of organotins in the ppb range The method can be used for very reliable analysis of water, soil,
or aquatic life, in the range of 500 ppt (100 ng) to 25 ppb (5 ,ug) Above 25 ppb the samples no longer fit a Beers Law plot and need to be diluted before developing the color
32
Trang 3References
1 N.F Cardarelli Controlled Release Pesticide Formulations
CRC Press, Cleveland, OH 1976, p 210
2 N.F Cardarelli Controlled Release Molluscicides, monogr
The University of Akron, Akron, OH 1977, p 136
3 N.F Cardarelli Controlled release organotins as mosquito
larvicides Mosq News 3:328-33 (1978)
4 A Sh Shakhabudinov and O.A Tataen Reaction between
tin (IV) and trihydroxyfluorones in the presence of antipyrene
J Anal Chem USSR 27:2163-66 (1972)
5 H Corbin Rapid and selective pyrocatechol violet method
for tin Anal Chem 45:534-37 (1973)o
6 R.M Dagnall, T.J West, and P Young The catechol violet
colour reaction for tin (IV) sensitized by cetyltrimethylam-
monium bromide Analyst (London) 92:27-30 (1967)
7 V Svoboda and V Chromy Reactions of metallochromic
indicators on micelles-III Talanta 13:237-44 (1966)
8 V.H Kulkarnl and M.L Good Phenylfluorone method for the determination of tin in submicrogram levels with cetyl-
trimethylammonium bromide Anal Chem 50:973-75 (1978)
9 N.H Furman Standard Methods of Chemical Analysis D
Van Nostrand Co., Inc., Princeton, NJ 1962, pp 1078-79
10 J.D Christie, T.L Carlson, L.R Sherman, and N.F Cardarelli Laboratory and field trials of a slow release organotin mollus- cicide in St Lucia In production University of Texas, Galveston, TX 77550 (1980)
Manuscript received July 23, 1979
Quantitative Determination of 2-Hydroxy-3-Methoxy-
6/3-Naltrexol (HMN), Naltrexone, and 6/3-Naltrexol
in Human Plasma, Red Blood Cells, Saliva, and Urine
by Gas Liquid Chromatography
K Verebey, A De Pace, D Jukofsky, J.V Volavka, and S.J MuI(~
New York State Division of Substance Abuse Services, Bureau of Laboratories and Testing, 80 Hanson Place,
Brooklyn, NY 11217
Introduction
2-Hydroxy-3-methoxy-6/3-naltrexol (HMN) is a minor metabolite of naltrexone in man (!-4) (Figure 1) It was isolated from human red blood cells and urine of subjects taking nal- trexone (1) A methylated 2,3-catechol type metabolite of naltrexone with the same mass unit as HMN was also reported (2) The assignment of the methyl group in the -3- position was initially based on the fact that this metabolite is excreted only
in the free form Naltrexone, 6/3-naltrexol and various similar molecules are being glucuronidated in the 3 position and large percentages of such molecules are excreted into the urine in the conjugated form If the 3 position is blocked by methylation,
no glucuronide can form, as it was observed with HMN (1) More recently, the structure of HMN was proven by synthesis (3) and by studies utilizing nuclear magnetic resonance spectra (4) In an earlier pharmacokinetic study, HMN was quantitated
in urine and expressed as 6/3-naltrexol equivalents (5) The recent availability of synthetic HMN allowed development of new and specific quantitative methodology In this communi- cation we report on clinically applicable methods for the de- termination of HMN, naltrexone and its major metabolite 6/3-naltrexol in plasma (or serum), RBC, saliva, and urine
Reprint requests to: Dr K Verebey, New York State Division of Substance Abuse Services, Bureau of Laboratories and Testing,
80 Hanson Place, Brooklyn, NY 11217
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