Matrix solid-phase dispersion extraction and gas chromatographic determination of chloramphenicol in muscle tissue

Article abstract of DOI:10.1021/jf025939d

A method based on matrix solid-phase dispersion (MSPD) was developed for the gas chromatographic (GC) determination of chloramphenicol (CAP) residues in animal muscle tissue. Muscle tissue was blended with octadecylsilyl-derivatized silica (C₁₈). A column made from the C₁₈/muscle tissue matrix was washed with n-hexane and acetonitrile/water (5 + 95), after which CAP was eluted with acetonitrile/water (50 + 50) and partitioned into ethyl acetate. The final extract was evaporated, and a trimethylsilyl derivative of CAP was prepared with Sylon HTP and detected by GC with an electron capture detector (ECD) and a mass spectrometer. For quantitation, the internal standard used was the meta isomer of CAP (m-CAP) for GC-ECD. Muscle tissue samples were fortified at three concentration levels. At 5, 10, and 15 μg/kg levels the respective mean recoveries were 93, 96, and 98%, and the repeatabilities were 13, 11, and 3%. The detection and quantitation limits with ECD were 1.6 and 4.0 μg/kg, respectively. No statistically significant difference was observed in the efficiency of CAP extraction from muscle tissue of various animals (bovine, porcine, and poultry) by the MSPD technique.

Full text of DOI:10.1021/jf025939d

J. Agric. Food Chem. 2003, 51, 871−875 871
Matrix Solid-Phase Dispersion Extraction and Gas
Chromatographic Determination of Chloramphenicol in Muscle
Tissue
HELENA KUBALA-DRINCIC,* DAVORIN BAZULIC, JASENKA SAPUNAR-POSTRUZNIK,
MIRELA GRUBELIC, AND GORAN STUHNE
Department of Residue Analysis, Croatian Veterinary Institute, 143 Savska Street,
HR-10000 Zagreb, Croatia
A method based on matrix solid-phase dispersion (MSPD) was developed for the gas chromatographic
(GC) determination of chloramphenicol (CAP) residues in animal muscle tissue. Muscle tissue was
blended with octadecylsilyl-derivatized silica (C18). A column made from the C18/muscle tissue matrix
was washed with n-hexane and acetonitrile/water (5 + 95), after which CAP was eluted with
acetonitrile/water (50 + 50) and partitioned into ethyl acetate. The final extract was evaporated, and
a trimethylsilyl derivative of CAP was prepared with Sylon HTP and detected by GC with an electron
capture detector (ECD) and a mass spectrometer. For quantitation, the internal standard used was
the meta isomer of CAP (m-CAP) for GC-ECD. Muscle tissue samples were fortified at three
concentration levels. At 5, 10, and 15 µg/kg levels the respective mean recoveries were 93, 96, and
98%, and the repeatabilities were 13, 11, and 3%. The detection and quantitation limits with ECD
were 1.6 and 4.0 µg/kg, respectively. No statistically significant difference was observed in the
efficiency of CAP extraction from muscle tissue of various animals (bovine, porcine, and poultry) by
the MSPD technique.
KEYWORDS: Chloramphenicol; gas chromatography; matrix solid-phase dispersion; muscle tissue;
residues
INTRODUCTION
Chloramphenicol (CAP) is a broad-spectrum antibiotic that
has been widely used in veterinary medicine for the treatment
of various infections. Today, however, its use in the treatment
of food-producing animals is prohibited in many countries
because of its proven toxicity to humans (1). The use of CAP
for therapeutic and prophylactic purposes may result in the
presence of its residues in edible animal tissues, which might
pose a risk to the consumer’s health (1). Due to possible abuse,
a permanent control of CAP levels in foodstuffs of animal origin
is indispensable. The structure of CAP is shown in Figure 1.
For the determination of CAP residues in foodstuffs of animal
origin, various methods are used, based on different analytical
techniques. The most commonly used methods for the deter-
mination of CAP in muscle tissue include gas chromatography
Figure 1. Chemical structure of CAP.
varied. Being rather time-consuming and complicated, they are
impractical for testing a large number of samples within a
reasonable period of time.
In this work, muscle tissue samples were prepared by means
of the matrix solid-phase dispersion (MSPD) technique as first
described by Barker et al. (11). The technique, which is very
simple and fast, permits the simultaneous determination of a
number of compounds in a single sample. In the past decade,
MSPD has been increasingly applied for the preparation of
different biological samples for the determination of residues
of veterinary drugs and contaminants (12). The referent literature
describes one application of this technique for the extraction of
CAP residues from muscle tissue and their determination by
LC with photodiode array detection (13). In the reported case,
however, the CAP detection level was not low enough and CAP
could not be detected in a 5 µg/kg spiked material.
(GC) (2-6) and liquid chromatography (LC) (7-10). In general,
the use of LC facilitates the extract cleanup process, whereas
lower detection levels are achieved by means of GC analysis
with an electron capture detector (ECD) or a mass spectrometer
(MS) (4). The procedures for CAP extraction from muscle tissue
and those of extract cleanup reported in the literature are widely
*
Author to whom correspondence should be addressed (telephone +385
612 3636; fax +385 1 619 0841; e-mail helena.kubala-drincic@
zg.hinet.hr).
1
1
0.1021/jf025939d CCC: $25.00 © 2003 American Chemical Society
Published on Web 01/16/2003

872 J. Agric. Food Chem., Vol. 51, No. 4, 2003
Kubala-Drincic et al.
Our objective was to develop a method that would include
the preparation of muscle tissue samples by the MSPD technique
for the GC-ECD determination of CAP. The method was
validated in terms of recovery, repeatability, and limits of
detection and quantitation. Our aim was also to find whether
the efficiency of CAP extraction by the MSPD technique
depended on the type of matrix (muscle tissue of various
animals) and to compare the results obtained by the MSPD
technique to those obtained by the method previously used in
this laboratory (14).
disk. The column content was pushed with a syringe plunger toward
the bottom, making sure not to compress it too much. The column was
washed with 10 mL of n-hexane and 12 mL of acetonitrile/water (5 +
9
5). CAP was eluted with 10 mL of acetonitrile/water (50 + 50) into
a tube. A 5 mL amount of water-saturated ethyl acetate was then added
into the eluate and stirred with a vortex mixer for 1 min. The sample
was centrifuged at 1700g for 10 min, and the top layer was separated
for evaporation. The extraction with ethyl acetate was then repeated.
The combined organic phase was subsequently evaporated on a rotary
evaporator to a volume below 0.5 mL and dried up with nitrogen. A
0.5 mL amount of methanol was then added to the dry residue, and
the sample was put in an ultrasonic bath for 5 min. The extract was
transferred into a 1.5 mL tube and well dried under a gentle stream of
nitrogen.
MATERIALS AND METHODS
Apparatus. Two chromatographic systems were used: (1) A gas
Method B. An 8 mL amount of acetonitrile/4% aqueous sodium
chloride (50 + 50) was added to the sample and stirred thoroughly.
After stirring, the sample was centrifuged at 4000g for 10 min. Five
milliliters of n-hexane was then added to the separated supernatant,
stirred thoroughly, and centrifuged at 1700g for 5 min. The top layer
was removed, and extraction with n-hexane was repeated. After the
separation of the top layer, 5 mL of water-saturated ethyl acetate was
added to the lower aqueous phase and stirred thoroughly. After the
centrifugation at 1700g for 5 min, the top layer was separated and
extraction with ethyl acetate was repeated. The combined organic phases
were evaporated to dryness, and the dry residue was dissolved in 3
mL of acetonitrile/water (5 + 95). The C18 column was washed with
5 mL of each methanol, chloroform, and methanol and with 10 mL of
water. The extract was transferred in the column, and the column was
washed with 5 mL of acetonitrile/water (5 + 95). CAP was eluted with
3 mL of acetonitrile/water (50 + 50). From the eluate CAP was
extracted twice, each time with 5 mL of water-saturated ethyl acetate.
After each extraction, it was centrifuged at 1700g, the top layer was
separated, and the combined organic phases were evaporated to dryness.
CAP was silylated directly in a tube after the evaporation of ethyl
acetate, the reagent was evaporated, and subsequently 100 µL of hexane
was added. CAP was determined by means of gas chromatography with
a mass spectrometer as detector, and deuterated CAP was used as the
internal standard (14). The course of the procedure following the last
ethyl acetate evaporation was modified in our laboratory and was
comparable to that of the MSPD method after ethyl acetate evaporation.
Derivatization. CAP was silylated by adding 50 µL of the silylating
reagent to the dry residue and stirred on a vortex mixer for 10 s. A
further 50 µL of n-hexane was then immediately added and stirred for
further 10 s (if the extract turned turbid, it was centrifuged at 1700g
for 5 min). A 1 µL amount of the extract was injected into the gas
chromatograph.
Method Validation. The linearity of the method was evaluated by
analysis of calibration graph samples. These were prepared by fortifying
blank samples of bovine muscle tissue with CAP and m-CAP
immediately after weighing. The 40, 50, 100, 150, and 200 µL amounts
of standard spiking solution were added to the calibration graph samples
prepared by the MSPD method and 30, 75, 150, 225, and 300 µL
amounts of the same solution were added to those prepared by method
B. For each point of the calibration graph six samples were prepared.
The concentrations ranged from 4 to 20 µg of CAP/kg for the MSPD
method and from 2 to 20 µg of CAP/kg of muscle tissue for method
B. The peak area ratios between CAP and m-CAP (y) were plotted
against the corresponding concentrations (x) by applying the least-
squares method.
chromatograph model ATI UNICAM 610 series was equipped with a
6
3
splitless injector, a Ni electron capture detector, and a fused silica
capillary column DB-1, 30 m × 0.32 mm i.d., film thickness ) 1 µm
(
J&W Scientific). The operating conditions were as follows: carrier
gas, argon with 5% methane; splitless time, 1 min; injector temperature,
50 °C; detector temperature, 310 °C; column temperature, 120 °C,
2
held for 1 min, raised to 280 °C at 20 °C/min, and held for 11 min;
injection volume, 1 µL. (2) A gas chromatograph model ATI UNICAM
AUTOMASS 615 GC SYSTEM 2 was equipped with a splitless
injector, a quadrupole mass spectrometer, and a fused silica capillary
column DB-1, 30 m × 0.25 mm i.d., film thickness ) 0.25 µm (J&W
Scientific). The operating conditions were as follows: carrier gas,
helium; splitless time, 1 min; injector temperature, 250 °C; transfer
line temperature, 280 °C; source temperature, 130 °C; column tem-
perature, 120 °C, held for 1 min, raised to 280 °C at 20 °C/min, and
held for 11 min; injection volume, 1 µL; electron ionization; ionization
energy, 70 eV.
Reagents and Solutions. The trimethylsilyl derivatizing reagent
Sylon HTP (hexamethyldisilazane/trimethylchlorosilane/pyridine, 3 +
+ 9) was purchased from Supelco Inc. Chloramphenicol was from
Sigma Chemical Co. Standard stock solution was prepared by dissolving
0.0 mg of CAP in 100 mL of methanol at 100 µg of CAP/mL. Standard
spiking solution was prepared by diluting the stock solution with
methanol at 0.2 µg of CAP/mL. The solution at 0.2 µg of CAP/mL
was also used as the standard working solution for GC-MS identification
of CAP. One hundred microliters of the solution was evaporated with
nitrogen and derivatized as described under Derivatization. The internal
standard working solution (m-CAP) at 1 µg of m-CAP/mL, dissolved
in ethanol, was a gift from the Federal Institute for Health Protection
of Consumers and Veterinary Medicine (Berlin, Germany). The
reference material used was BCR-445, lyophilized porcine muscle tissue
with the certified value of 8.9 µg of CAP/kg incurred material
1
1
(
Community Bureau of Reference).
Extraction Materials. Bulk C18 (octadecylsilyl derivatized silica,
4
0-63 µm) was purchased from Merck. The C18 was cleaned by
sequentially washing a 50 mL column containing bulk C18 (20 g) with
column volumes each of n-hexane, dichloromethane, and methanol
and then dried. Plastic syringe barrels of 10 mL, washed with hot soapy
water, rinsed with demineralized water, and air-dried, were used as
extraction columns.
Sample Preparation. MSPD Method (Method A). Muscle tissue was
minced by means of a mixer, and 2 g of the sample was weighed into
a glass grinding mortar. A 30 µL amount of internal standard working
solution was added. For recovery experiments, 50, 100, or 150 µL of
standard spiking solution was added to the sample to obtain three
spiking levels (5, 10, and 15 µg of CAP/kg).
Method Used Thus Far (Method B). A 30 µL amount of the internal
standard working solution was added to 3 g of minced muscle tissue.
For recovery experiments, 75, 150, or 225 µL of standard spiking
solution was added to obtain the identical spiking levels as with the
MSPD method.
2
The accuracy of both methods was checked using the samples of
muscle tissue to which a known CAP quantity had been added. The
measured CAP levels were expressed as percentages of the CAP
quantities added (recovery). Considering that the maximum residue limit
(MRL) for muscle tissue in Croatia is 10 µg of CAP/kg (15), checks
were made at three levels corresponding to 0.5, 1, and 1.5 times the
MRL (5, 10, and 15 µg of CAP/kg of muscle tissue) with six samples
Extraction and Cleanup. Method A. A 3 g amount of C18 was added
to the sample and blended by means of a glass pestle until a
homogeneous mixture was obtained. Two filter paper disks were
inserted at the bottom of the syringe, followed by 0.5 g of C18 and
m
for each level (16). For each level the mean value (X ) and relative
standard deviation (RSD) were calculated. The accuracy of the MSPD
method was also checked on the basis of the analysis of four samples
of the reconstituted reference material with the certified value of 8.9
µg of CAP/kg.
C18/muscle tissue matrix blend, and covered with another filter paper

Chloramphenicol in Muscle Tissue
J. Agric. Food Chem., Vol. 51, No. 4, 2003 873
Figure 2. Chemical structure of disilylated trimethylsilyl-CAP derivative.
Table 1. CAP Recovery from Muscle Tissue Samples Fortified at
Three Levels, Prepared by the Two Methods
recovery %
method A
method B
RSD, %
CAP added,
µg/kg
Xm, %
RSD, %
Xm, %
a
b
a
b
a
4a
5
100 (93 )
10 (13 )
99
a
a
a
a
1
0
96
11
104
3
a
a
a
a
15
98
3
105
3
a
Bovine muscle tissue (n ) 6). b Bovine, porcine, and chicken muscle tissues
(n ) 18).
The repeatability of the method was assessed using the calculated
RSD values.
To determine the limit of detection (LOD), 20 muscle tissue samples
with a CAP content below the LOD were analyzed. The samples were
prepared by both methods. The detection limit was calculated as the
apparent content corresponding to the value of the mean plus 3 times
the standard deviation for 20 blank determinations (17), and the
calibration line was based on the peak height ratio of CAP and m-CAP.
The limit of quantitation (LOQ) was determined as the smallest
measured content of the analyte in a sample that could be quantified
with a specified degree of accuracy and precision (16). LOQ cor-
responded to the lowest concentration point on the calibration graph.
CAP Identification. In samples prepared by the MSPD method CAP
was identified by means of a mass spectrometer after GC separation.
Electron ionization was applied, and the samples were tested for the
presence of disilylated trimethylsilyl-CAP-characteristic ions (m/z 208,
Figure 3. GC-ECD chromatograms of muscle tissue samples prepared
by the MSPD method: (a) blank bovine muscle tissue; (b) bovine muscle
tissue fortified with CAP at 15 µg/kg. Peak 1, m-CAP; peak 2, CAP.
taken from different animals at the level of 5 µg/kg (Student’s
t test, P >0.05). On the basis of this observation, 93% recovery
was calculated as the mean value for bovine, porcine, and
chicken muscles at the level of 5 µg of CAP/kg (Table 1).
Comparison of the two methods failed to demonstrate any
significant difference in terms of the efficiency of CAP
extraction from bovine muscle tissue at levels of 5 and 10 µg
of CAP/kg (Student’s t test, P > 0.05).
225, and 242) (2). The analysis included the standard working solution
of CAP and the extract of a bovine muscle sample prepared by the
MSPD method, to which 10 µg of CAP/kg had been added. The
structure of disilylated trimethylsilyl-CAP is shown in Figure 2.
Repeatability. Repeatability results are presented in Table
1
(RSD values). Considering that no statistically significant
difference was noted in the efficiency of the MSPD method as
a function of different matrices, the repeatability of 13% at the
level of 5 µg of CAP/kg was calculated from the results for
bovine, porcine, and chicken muscle tissues (Table 1).
Detection Limit. The CAP detection limits were 1.6 µg of
CAP/kg for the MSPD method and 0.7 µg of CAP/kg, for
method B.
Quantitation Limit. The quantitation limits for CAP were
set at 4 and 2 µg of CAP/kg levels for the MSPD method and
method B, respectively. They were determined by analysis of
spiked tissue samples (n ) 6) at concentration levels of 4 µg
of CAP/kg for the MSPD method and 2 µg of CAP/kg for
method B. The respective CAP recoveries were 103 and 99%,
with an RSD of 5%.
RESULTS
Linearity. The calibration graphs for CAP determination by
the two methods were linear over the concentration ranges tested
(
4-20 and 2-20 µg of CAP/kg, respectively). CAP determi-
nation by the MSPD method followed the equation y ) -0.020
+
0.003x (correlation coefficient r ) 0.9992) and by method
B y ) 0.026 + 0.003x (r ) 0.9975).
Accuracy. The results of accuracy testing are presented in
Table 1. Figure 3 shows the chromatograms of the bovine
muscle tissue samples prepared by the MSPD method without
any CAP added and with 15 µg of CAP/kg added.
The accuracy of the MSPD method was also evaluated by
analyzing the certified reference material. The measured CAP
content was expressed as a percentage of the certified value.
The mean value was 108%, with an RSD of 3%.
CAP Identification. The peak detected in the sample extract
had the same retention time as the peak detected in the standard
CAP working solution with identical characteristic ions (Figure
The relationship between different matrices (muscle tissues
of different animals) and the efficiency of CAP extraction by
the MSPD technique was examined on samples of chicken and
pork tissues (six samples of each tissue) to which 5 µg of CAP/
kg was added. CAP recovery was 90%, with an RSD of 15%,
for the chicken tissue and 90%, with an RSD of 13%, for pork.
It was established that there was no significant difference in
the efficiency of CAP extraction from muscle tissue samples
4
).
DISCUSSION
Extraction of drug residues from a tissue is a demanding task
because it involves a very complex biological matrix. Conven-
tional extraction and extract cleanup techniques are usually time-
consuming and complicated. Besides, they require large volumes

874 J. Agric. Food Chem., Vol. 51, No. 4, 2003
Kubala-Drincic et al.
to be acceptable for the determination of CAP residues in muscle
tissue. The detection limit of a method is subject to a number
of factors, such as sample quantity, efficiency of the extraction
technique, final volume of the extract, quantity of the extract
injected in the instrument, sensitivity, and certain specific
features of the detector unit used, as well as the presence of
interfering compounds (19). Besides, methods for calculating
LOD values have not been standardized. Therefore, comparison
of the results published in the literature is hardly possible as
most of the factors influencing the LOD differ from one paper
to another (5, 7, 9, 13).
Figure 4. Selected ion chromatograms of a bovine muscle tissue sample
fortified with CAP at 10 µg/kg and prepared by the MSPD technique: (a)
m/z 242; (b) m/z 225; (c) m/z 208.
of solvents and make the preparation of a large number of
samples within a reasonable time impractical.
The GC-MS identification of CAP confirms the suitability
of the MSPD method for the determination of CAP in muscle
tissue and the sensitivity of the mass spectrometer as a gas
chromatographic detector for the identification of CAP at the
level of 10 µg of CAP/kg.
Comparative results show that the MSPD method facilitates
selective and efficient extraction of CAP from animal muscle
tissue. Being fast and easy to use, this method permits analysis
of a larger number of samples (seven samples per sequence
compared to four by the former method) using a small quantity
of solvents.
Most methods for GC determination of CAP in muscle tissue
include several steps (2-6). Tissue homogenization is followed
by the addition of a suitable solvent for extraction. After
centrifugation, the extract is separated and a defatting solvent
is added. CAP is then re-extracted from the extract. Further
cleanup is usually performed either by means of liquid-liquid
extraction or by solid-phase extraction. The final extract is
evaporated and CAP is silylated. Acetonitrile (2, 4, 5) and ethyl
acetate (3) are most commonly used for CAP extraction from
muscle tissue. Lipids are usually removed with n-hexane
(4, 5). Solid-phase extraction (4) generally serves for the extract
cleanup. Some authors combine the extract cleanup on a silica
gel column with LC purification (3) or cleaning by immuno-
affinity chromatography (5).
The method used in our laboratory so far has been rather
time-consuming and complicated to perform because it involves
six liquid-liquid extractions and seven cetrifugation and extract
separation cycles. Our aim was therefore to facilitate sample
preparation by applying the MSPD technique.
LITERATURE CITED
(
1) Settepani, J. A. The hazard of using chloramphenicol in food
animals. J. Am. Vet. Med. Assoc. 1984, 184, 930-931.
(
2) Malisch, R. Multimethode zur Bestimmung der R u¨ ckst a¨ nde von
Chemotherapeutica, Antiparasitica und Wachstumf o¨ rderern in
Lebensmitteln tierischer Herkunft. Z. Lebensm. Unters. Forsch.
1
987, 184, 467-477.
The mechanisms included in the MSPD technique make it
possible for sample homogenization, destruction of cellular
structure, extraction, and cleanup to be carried out in a single
procedure. Further extract cleanup prior to the analyte deter-
mination may be performed but need not be necessary (11).
In MSPD procedures, the proportion of tissue and solid phase
is usually 1:4 (0.5 g of tissue and 2 g of solid phase), but in our
case it was slightly modified (2 g of tissue and 3 g of solid
phase) because of the small quantities of CAP that had to be
detected while maintaining the quantities that are acceptable
for this particular technique (11). The interfering compounds
were removed by the column washing with n-hexane and an
aqueous solution of acetonitrile. After the evaporation of the
final extract, CAP was silylated before being injected in the
gas chromatograph. The reagent used for silylation was hexa-
methyldisilazane/trimethylchlorosilane/pyridine (3 + 1 + 9).
The silylation reagent is usually removed (wholly or partly) by
evaporation before the final solvent is added (4, 5). However,
the silylated CAP may be lost (18). We have omitted this step
because a loss of silylated CAP was noted, which seriously
affected the sensitivity of the method.
(
3) van Ginkel, L. A.; van Rossum, H. J.; Zoontjes, P. W.; van
Blitterswijk, H.; Ellen, G.; van der Heeft, E.; de Jong, A. P. J.
M.; Zomer, G. Development and validation of a gas chromato-
graphic-mass spectrometric procedure for the identification and
quantification of residues of chloramphenicol. Anal. Chim. Acta
1
990, 237, 61-69.
(
4) F u¨ rst, P.; Kr u¨ ger, C.; Meemken, H. A.; Groebel, W. GC/MS-
Bestimmung von Chloramphenicol in Lebensmitteln im ppt-
Bereich. Dtsch. Lebensm. Rundsch. 1988, 4, 108-113.
5) Gude, T.; Preiss, A.; Rubach, K. J. Determination of chloram-
phenicol in muscle, liver, kidney and urine of pigs by means of
immunoaffinity chromatography and gas chromatography with
electron-capture detection. J. Chromatogr. B 1995, 673, 197-
204.
(
(6) Mineo, H.; Kaneko, S.; Koizumi, I.; Asida, K.; Akahori, F. An
analytical study of antibacterial residues in meat: The simulta-
neous determination of 23 antibiotics and 13 drugs using gas
chromatography. Vet. Hum. Toxicol. 1992, 34, 393-397.
(
7) Hummert, C.; Luckas, B.; Siebenlist, H. J. Determination of
chloramphenicol in animal tissue using high-performance liquid
chromatography with a column-switching system and ultraviolet
detection. J. Chromatogr. B 1995, 668, 53-58.
(
8) Li, T. L.; Chung-Wang, Y. J.; Shih, Y. C. Determination and
confirmation of chloramphenicol residues in swine muscle and
liver. J. Food Sci. 2002, 67, 21-28.
The efficiency of CAP extraction (Table 1) by both methods,
at all three levels, was in accordance with the criteria as defined
in the European Communities recommendations (16). According
to the criteria, the recoveries at those levels should range from
(9) Delepine, B.; Sanders, P. J. Determination of chloramphenicol
in muscle using a particle beam interface for combining liquid
chromatography with negative-ion chemical ionization mass
spectrometry. J. Chromatogr. 1992, 582, 113-121.
10) Hormazabal, V.; Ynestad, M. Simultaneous determination of
chloramphenicol and ketoprofen in meat and milk and chloram-
phenicol in egg, honey, and urine using liquid chromatography-
mass spectrometry. J. Liq. Chromatogr. Relat. Technol. 2001,
7
0 to 110%. Our results show the accuracy and repeatability of
the MSPD method to be fully comparable to those of the highly
efficient methods described by Hummert et al. (7) and Delepine
et al. (9).
The detection and quantitation limits for CAP determined by
the MSPD method (1.6 and 4 µg of CAP/kg) were higher than
those by the method used so far (0.7 and 2 µg of CAP/kg).
However, considering that the MRL for animal muscle tissue
in Croatia is 10 µg of CAP/kg, the MSPD method is considered
(
2
4, 2477-2486.
(
11) Barker, S. A.; Long, A. R.; Short, C. R. Isolation of drug residues
from tissues by solid phase dispersion. J. Chromatogr. 1989,
475, 353-361.

Chloramphenicol in Muscle Tissue
J. Agric. Food Chem., Vol. 51, No. 4, 2003 875
(
12) Barker, S. A. Applications of matrix solid-phase dispersion in
food analysis. J. Chromatogr. A 2000, 880, 63-68.
(16) Commission of the European Communities, Draft SANCO/1805/
2000 rev. 6.
(17) Commission of the European Communities, Commission Deci-
sion 93/256, April 14, 1993. Off. J. Eur. Communities 1993, L
(
13) Le Boulaire, S.; Bauduret, J. C.; Andre, F. Veterinary drug
residues survey in meat: An HPLC method with a matrix solid
phase dispersion extraction. J. Agric. Food Chem. 1997, 45,
1
18/64.
2
134-2142.
(18) Kijak, P. J. Confirmation of chloramphenicol residues in bovine
(
14) Chloramphenicolsconfirmation of chloramphenicol in meat by
gas chromatography-mass spectrometry. In Agriculture-Veteri-
nary Drug ResiduessResidues in Food-Producing Animals and
Their Products: Reference Materials and Methods; Heitzman,
R. J., Ed.; Commision of the European Communities: Brussels,
Belgium, 1992; pp 161-166.
milk by gas chromatography/mass spectrometry. J. AOAC Int.
1
994, 77, 34-40.
(
19) Barker, S. A.; Long, A. R. Tissue drug residue extraction and
monitoring by matrix solid phase dispersion (MSPD)-HPLC
analysis. J. Liq. Chromatogr. 1992, 15, 2071-2089.
(
15) Regulation of the permissible levels of pesticides, toxins,
mycotoxins, metals and histamines and similar substances that
may be present in foodstuffs and on other terms and conditions
governing the safety of foodstuffs and objects intended for
general use; Official Gazette 46; Zagreb, Croatia, 1994; pp
Received for review September 5, 2002. Revised manuscript received
November 7, 2002. Accepted December 2, 2002.
1
579-1586.
JF025939D