Spiked drinks

A Cosmopolitan cocktail sits on a drink coaster that is used to detect date rape drugs. The coaster has test sensors that turn blue in 30 seconds if a spiked drink splashes on it. Although colleges around the country have bought similar coasters, law enforcement experts warn that the coasters are not always effective and may cause people to have a false sense of security. 

The developed method was applied to spiked drinking water, ground water, and river water samples and was used to detect halo-phenols in paper mill effluents. The described method is rapid and can be applied to control the water quality of environmental waters with respect to these important classes of organic pollutants and ammonia. 

Cavalli et al. [36] report a method based on ion-exclusion chromatography and MS detection. The column used is a microbore lonPac ICE-ASI column (250 x 4 mm i.d.). MS was in ion selected-ion monitoring (SIM) mode by a single quadrupole system with electrospray ionization. Large voliunes of spiked drinking water were also injected. The LOD was 0.2 ppb for 500 pL injection volume. 

Quality Assurance Recovery experiments were conducted by spiking drinking water and river water samples, respectively, with known amounts of the analytes at neutral pH and pH 2. (Quantification of the compounds was obtained by using a nine-point external calibration curve ranging between 0.001 and 0.3 mg/L,... 

Recovery Recovery experiments were conducted by spiking drinking ... 

A potential concern with the hydroxybutyrates has to do with the use of one member of the series as an illieit drug. So-called gamma-butyrate, 4-hydroxybutyric aeid, is the infamous date-rape drug, which has caused fatalities to victims who have ingested it with spiked drinks. 

In according to proposed procedure the drinking water samples with spiked copper (II) standai d solution and the copper-smelting plant wastewater samples have been analyzed. The found results were verified by atomic absoi ption spectrometry. The developed method (standard addition version) was found suitable for determination of Cu (II) in drinking water and industrial wastewater. 

Figure 2.11 (a) HPLC chromatogram obtained for a sample of drinking water spiked with... 

Figure 5.3 Analysis of 100 ml of (a) surface water and (b) drinking water sample spiked with 0.1 pig/ml of microcystins, using column-switching HPLC 1, microcystin-RR 2, microcystin-YR 3, microcystin-LR. Reprinted from Journal of Chromatography A, 848, H. S. Lee et al, On-line trace enrichment for the simultaneous determination of microcystins in aqueous samples using high performance liquid chromatography with diode-array detection , pp 179-184, copyright 1999, with permission from Elsevier Science.

Table I shows the summarized recovery data with spiking levels and precision. This table includes, for purposes of comparison with polar compounds, some data for nonpolar compounds [volatile organics (VO) and the neutrals in WABN] also, the recoveries for NOVA are not for drinking water. The mean recovery for 217 compounds was 82 the mean relative standard deviation (RSD) (for three or more measurements) was 12. Several observations can be made in regard to these data (1) The best recoveries and precision are obtained for VO and ESSA compounds. (2) NEWS organics, a new class of analytes, are...

Mean recoveries are for triplicate determinations from drinking water, spiked at 0.8-1.2 ppb (nominally 1 ppb), plus triplicate determinations from a 60-40 industrial-municipal waste water, spiked at 40-63 ppb (nominally 50 ppb). c Mean recoveries are for triplicate determinations from 60-40 industrial-municipal waste water only, spiked at 40-63 ppb (nominally 50 ppb). 

Mean recoveries are for triplicate determinations from drinking water, spiked at 0.5-5 ppb (nominally 1 ppb), using XAD-4 resin sorbent columns. 

To estimate the validity of the results obtained by GC-MS analysis of XAD extracts, eight fortified drinking water extracts were analyzed by two GC-MS laboratories. Several target-compound mixture solutions were prepared, and fortified extract was made by spiking various aliquots of the mixture solutions into analyte-free LV-XAD extracts. The extracts were fortified with at least two concentrations of target compounds (see the list below). By assuming a 150-L representative water extract, the analyte amounts would be equivalent to approximately 1-100 ng/L of water. 

Another performance requirement often specified is spike recovery. Sometimes, response to analyte is affected by something else in the sample. We use the word matrix to refer to everything else in the sample other than analyte. A spike, also called a fortification, is a known quantity of analyte added to a sample to test whether the response to a sample is the same as that expected from a calibration curve. Spiked samples are analyzed in the same manner as unknowns. For example, if drinking water is found to contain 10.0 pg/L of nitrate, a spike of 5.0 pg/L could be added. Ideally, the concentration in the spiked portion found by analysis will be 15.0 pg/L. If a number other than 15.0 pg/L is found, then the matrix could be interfering with the analysis. 

Spike recovery and detection limit. Species of arsenic found in drinking water include AsO (arsenite), AsO - (arsenate), (CH3)2As02 (dimethylarsinate), and (CH3)AsO (methylarsonate). Pure water containing no arsenic was spiked with 0.40 pg arsen-ate/L. Seven replicate determinations gave 0.39, 0.40, 0.38, 0.41, 0.36, 0.35, and 0.39 pg/L.12 Find the mean percent recovery of the spike and the concentration detection limit (pg/L). 

A bibliographic search has shown that the majority of the HPLC techniques for determining OPPs and OCPs have been applied to the determination of residues in surface, ground- and drinking water. Table 5 lists pesticides determined, extraction and cleanup methods used, HPLC conditions, contaminated matrix and analyte detection limits taken from the literature for water, animal tissues, milk, fruit and vegetables, and cereals. The majority of the studies were done on spiked samples, and in the best of cases there were few real samples analyzed. 

Fig. 2.4. Speciation analysis of drinking water spiked with 10 ppb Pb2+ as a function of sample pH performed with Pb2+-selective electrode described in Ceresa et al. [17]. The dotted line represents the behaviour calculated on the basis of lead-carbonate complexation [12]. Reprinted from Ref. [12] (p. 205), with permission from Elsevier.

This has earned Rohypnol its most common nickname the date rape drug. On college campuses, women are warned not to leave their drinks unattended or accept a drink from someone they do not know. Because Rohypnol is colorless and odorless, it can be used to spike just about any beverage. When placed in an alcohlic beverage, Rohypnol increases the effects of the alcohol and the rate at which the person will start to feel drunk. ... 

First, the autocorrelation function must be computed. In the example plot a strong seasonal effect could be seen in the explanatory variable (nitrate concentration in the feeder stream) as well as in the dependent variable (nitrate concentration in the drinking water reservoir) (Fig. 6-2). The autocorrelation function (Fig. 6-16) has, therefore, the expected exponentially decreasing shape and, because of the seasonal fluctuations, increasing values at x = 12, 24,. .. A better tool for determining the order is the partial autocorrelation function. This function shows the partial correlation between x(t) and x(t - x) and ignores the influences of other variables, e.g. x(t - x + 1). It reveals the order one by the spike at x = 1 in Fig. 6-17. 

An important objective of this project was to provide elements of method validation by estimating the bias, that is to say the difference between the measured value and the true value of measurands in samples. This can be underlined through a proficiency testing analysing either a spiked pure water or a matrix sample (drinking water), according to the diagram represented in Fig. 3. 

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