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A rapid determination method is presented for gold (Au(3+)) and platinum (Pt(4+)) in tissues using matrix-assisted laser desorption ionization quadrupole time-of-flight mass spectrometry (MALDI-Q-TOF-MS). Au and Pt ions in wet-ashed tissue solution were reacted with diethyldithiocarbamate (DDC), and the resulting chelate complex ions Au(DDC)2 (+) and Pt(DDC)3 (+) were detected by MALDI-Q-TOF-MS using α-cyano-4-hydroxycinnamic acid as a matrix. The limit of detection (LOD) was 0.8 ng/g tissue and the quantification range was 2-400 ng/g for Au, and the LOD was 6 ng/g tissue and the quantification range was 20-4,000 ng/g for Pt. The Pt levels detected by MALDI-Q-TOF-MS in several tissues of a patient overdosed with cisplatin were nearly the same as those detected by flow-injection electrospray ionization mass spectrometry. The LODs of Au and Pt were 0.04 pg per well (sample spot) and 0.3 pg per well, respectively. To our knowledge, this is the first attempt to quantify Au(3+) and Pt(4+) ions in tissues by MALDI-Q-TOF-MS.

A rapid and sensitive electrospray ionization tandem mass spectrometric (ESI-MS-MS) procedure was developed for the determination of cyanide (CN(-)). CN(-) in biological fluids was reacted with NaAuCl(4) to produce dicyanogold, Au(CN)(2)(-), which was extracted with methyl isobutyl ketone (MIBK). One microliter of the extract was injected directly into an ESI-MS-MS instrument. Quantification of CN(-) was performed by selected reaction monitoring of the product ion CN(-) at m/z 26 that derived from precursor ion Au(CN)(2)(-) at m/z 249. CN(-) could be measured in the quantification range of 10(-7) to 5x10(-5) M with the limit of detection at 4x10(-8) M using 10 microL of urine within 10 min. A victim's urine and gastric content were diluted with water to 4-fold and 500-fold and measured, respectively.

Inorganic arsenic species are metabolized to monomethylarsonic acid (MMA(V)) and dimethylarsinic acid (DMA(V)) and excreted into urine. A simple, rapid and sensitive method has been developed using electrospray ionization tandem mass spectrometry (ESI-MS-MS) for the simultaneous determination of MMA(V) and DMA(V). MMA(V) and DMA(V) in a sample were allowed to react with citric acid (CiA). Adduct compounds were extracted together with isoamyl alcohol (IAA). An aliquot (1-microL) of the IAA layer was directly injected into the ESI-MS-MS instrument, and was detected within 1 min. Quantification was done using selected reaction monitoring for MMA(V) and DMA(V) as follows: [MMAH + 2CiA - 3H(2)O](+) --> [MMAH + CiA - 2H(2)O](+) [DMAH + CiA + MeOH - 2H(2)O](+) --> [DMAH + MeOH - H(2)O](+) where MMAH and DMAH denote the protonated forms of MMA(V) and DMA(V), and MeOH denotes methanol (carrier liquid in ESI-MS-MS). This method was validated for the analysis of urine samples. The limit of detection of As was 0.3 microg L(-1) for MMA(V) and 0.6 microg L(-1) for DMA(V) using 10 microL of sample solution. Results were obtained in <10 min with a linear calibration range of 3-100 microg L(-1). Inorganic arsenic compounds (and other organic arsenic compounds) found in urine did not interfere with the detection of MMA(V) and DMA(V). Concentrations of MMA(V) and DMA(V) in the reference urine SRM 2670a were estimated after partial purification, and those in urine of a patient treated with As(2)O(3) were measured after dilution.

Arsenic pollution of public water supplies has been reported in various regions of the world. Recently, some cancer patients are treated with arsenite (As(III)); most Japanese people consume seafoods containing large amounts of negligibly toxic arsenic compounds. Some of these arsenic species are metabolized, but some remain intact. For the determination of toxic As(III), a simple, rapid and sensitive method has been developed using electrospray ionization mass spectrometry (ESI-MS). As(III) was reacted with a chelating agent, pyrrolidinedithiocarbamate (PDC, C(4)H(8)NCSS(-)) and tripyrrolidinedithiocarbamate-arsine, As(PDC)(3), extracted with methyl isobutyl ketone (MIBK). A 1 microL aliquot of MIBK layer was directly injected into ESI-MS instrument without chromatographic separation, and was detected within 1 min. Arsenate (As(V)) was reduced to As(III) with thiosulfate, and then the total inorganic As was quantified as As(III). This method was validated for the analysis of urine samples. The limit of detection of As was 0.22 microg L(-1) using 10 microL of sample solution, and it is far below the permissible limit of As in drinking water, 10 microg L(-1), recommended by the WHO. Results were obtained in <10 min with a linear calibration range of 1-100 microg L(-1). Several organic arsenic compounds in urine did not interfere with As(III) detection, and the inorganic As in the reference materials SRM 2670a and 1643e were quantified after the reduction of As(V) to As(III).