Milk detection

TABLE 4.15 Recovery, repeatability, and reproducibility for milk detection"... 

Oxacillin and cloxacillin are the most widely used isoxazolyl penicillins, the latter being particularly appropriate for treatment or prevention of bovine staphylococcal mastitis. Following intramammary treatment of a lactating cow with three successive infusions of 200 mg/48 h each of sodium cloxacillin, residues were present in milk (detection limit equal to 3 ppb) from the treated quarter for 60 h after the last infusion crossover from treated to untreated quarter was also observed (59). When cloxacillin benzathine was administered by the intramammary route to dairy cows in the dry period at a dosage of 500 mg/quarter, cloxacillin residues were present neither in serum ( 25 ppb) sampled after 5 days of drug administration nor in milk ( 5 ppb), including the milk collected... 

Medina used an inhibition assay to detect SEE in 2005 [44], SEE was immobilized on the sensing surface. Known concentrations of SEE were then incubated with anti-SEE antibodies, and the incubation solution was passed across the sensing surface. Detections in buffer were seen for concentrations ranging from 0.78 ng/mL to 50 ng/mL. In whole and skim milk, detections were demonstrated for 0.312 ng/mL to 25 ng/mL. 

Borkovi M. Sn elova, J. Possibilities of different animal 41. milk detection in mUk detection in milk and dairy products—A review. Czech J. Food Sci. 2005, 23,41-50. 

The determination of tilmicosin extracted from cow and sheep milk was conducted on a phenyl column (A = 280nm) using a complex 30-min 50/50/0 - 15/85/0-> 15/0/85 acetonitrile/water/water (20mM dibuyflamine phosphate at pH 2.6) gradient This successfully separated the analyte from a host of co-extracted peaks [1460]. Standards ranged from 0.01 to lOpg/mL (sheep milk) and 0.025 to 0.5(ig/mL (cow milk). Detection and quantitation limits were 0.0125 pg/mL and 0.05 pg/mL, respectively. 

Hakim SAE, Mijovid V, Walker J (1961a) Experimental transmission of sanguinarine in milk detection of a metabolic product. Nature (London) 189 201-204 Hakim SAE, Mijovid V, Walker J (1961b) Distribution of certain poppy-fumaria alkaloids and a possible link with the incidence of glaucoma. Nature (London) 189 198-201... 

In milk fat, cholesterol is associated with Hpoproteins in the milk fat globule. It is also a component of animal membranes and controls rigidity and permeabihty of the membranes. Cholesterol has interesting surface properties and can occur in Hquid crystalline forms. Plants contain sterols such as P-sitosterol [83-46-5] (4b) or stigmasterol [83-48-7] (4c). Their functions in plant metaboHsm are not yet well understood. Analysis of sterols has proven useful for detection of adulteration of edible fats (9). 

Milk consists of 85—89% water and 11—15% total soflds (Table 1) the latter comprises soflds-not-fat (SNF) and fat. Milk having a higher fat content also has higher SNF, with an increase of 0.4% SNF for each 1% fat increase. The principal components of SNF are protein, lactose, and minerals (ash). The fat content and other constituents of the milk vary with the animal species, and the composition of milk varies with feed, stage of lactation, health of the animal, location of withdrawal from the udder, and seasonal and environmental conditions. The nonfat soflds, fat soflds, and moisture relationships are well estabhshed and can be used as a basis for detecting adulteration with water (qv). Physical properties of milk are given in Table 2. 

Phosphatase Test. The phosphatase [9001-78-9] test is a chemical method for measuring the efficiency of pasteurization. AH raw milk contains phosphatase and the thermal resistance of this enzyme is greater than that of pathogens over the range of time and temperature of heat treatments recognized for proper pasteurization. Phosphatase tests are based on the principle that alkaline phosphatase is able, under proper conditions of temperature and pH, to Hberate phenol [108-95-2] from a disodium phenyl phosphate substrate. The amount of Hberated phenol, which is proportional to the amount of enzyme present, is determined by the reaction of Hberated phenol with 2,6-dichloroquinone chloroimide and colorimetric measurement of the indophenol blue formed. Under-pasteurization as well as contamination of a properly pasteurized product with raw milk can be detected by this test. 

A widely used instmment for air monitoring is a type of ionization chamber called a Kaimn chamber. Surface contamination is normally detected by means of smears, which are simply disks of filter paper wiped over the suspected surface and counted in a windowless proportional-flow counter. Uptake of tritium by personnel is most effectively monitored by urinalyses normally made by Hquid scintillation counting on a routine or special basis. Environmental monitoring includes surveillance for tritium content of samples of air, rainwater, river water, and milk. 

In the Netherlands, milk from every farmer is tested twice a year for the extent of lipolysis, using the BDI method. However, the BDI method only detects long chain FFA, which does not induce off-flavor. On the other hand, headspace sampling does detect the short chain FFA. The aim of this study is to compare the BDI method to headspace sampling. 

The opportunity of use of a ternary complex of ions Eu(III) with oxatetracycline (OxTC) and citrat-ions (Cit) for luminescent detection of OxTC in milk after chromatographic isolation is shown. 

Many proteins and polymers have been analyzed on SynChropak GPC and CATSEC columns. Table 10.6 lists some of the published applications. The use of a surfactant to analyze the caseins in milk is illustrated in Eig. 10.12. Viruses have also been analyzed on SynChropak GPC columns, as seen in the chromatogram from Dr. Jerson Silva of the University of Illinois (Pig. 10.13). Dr. Nagy and Mr. Terwilliger analyzed cationic polymers on a series of CATSEC columns using differential viscometry as detection (Pig. 10.14) (9). 

A. Glausch, J. Hahn and V. Schurig, Enantioselective determination of chiral 2,2, 3,3, 4,6-hexachlorohiphenyl (PCB 132), in human milk samples by multidimensional gas clnomatography/electi on capture detection and by mass spectrometiy , Chemosphere 30 2079-2085 (1995). 

Children are expected to be exposed to methyl parathion by the same routes that affect adults. Small children are more likely to come into contact with methyl parathion residues that may be present in soil and dust both outside and inside the home, due to increased hand-to-mouth activity and playing habits. Methyl parathion has been detected in a few samples of breast milk, indicating potential for exposure of nursing infants. However, available data are not adequate for determination of the importance of this route of child exposure. 

The available evidence suggests that excretion of methyl parathion metabolites in humans and animals following acute oral exposure is essentially the same and occurs rapidly. Excretion occurs primarily via the urine. Methyl parathion can also be excreted in breast milk, although it has been detected only in a limited number of samples from women of central Asia, for which exposure data were not available (Lederman 1996) (see also Section 3.4.2.2). A study in rats also reported excretion of methyl parathion in the milk (Golubchikov 1991 Goncharuk et al. 1990). 

An extensive study was undertaken to determine if pesticide residues are present in any infant formula products (Gelardi and Mountford 1993). Milk- and soy-based formulas were analyzed, as was the water used to make the formula. No pesticide residues, including methyl parathion, were detected in any infant formula manufactured in the United States. Thus, it does not appear that infants will be exposed to... 

Baynes RE, Bowen JM. 1995. Rapid determination of methyl parathion and methyl paraoxon in milk by gas chromatography with solid-phase extraction and flame photometric detection. J Assoc Off Anal Chem 78 812-815. 

No data were located concerning whether pharmacokinetics of endosulfan in children are different from adults. There are no adequate data to determine whether endosulfan or its metabolites can cross the placenta. Studies in animals addressing these issues would provide valuable information. Although endosulfan has been detected in human milk (Lutter et al. 1998), studies in animals showed very little accumulation of endosulfan residues in breast milk (Gorbach et al. 1968 Indraningsih et al. 1993), which is consistent with the rapid elimination of endosulfan from tissues and subsequent excretion via feces and urine. There are no PBPK models for endosulfan in either adults or children. There is no information to evaluate whether absorption, distribution, metabolism, or excretion of endosulfan in children is different than in adults. 

---